Monday, July 31, 2006

Teach a person to shoot: Part 2

by B.B. Pelletier

Teach a person to shoot: Part 1

Making students aware of safety
How do you make a student as aware of gun safety as the instructor? You make a game of it. First, you teach the students the most basic safety rules, with the first one being Never point a gun at anything you do not intend shooting. That's sometimes watered down to Always point a gun in a safe direction, but I have seen too many people (myself included) who cannot initially appreciate how far a bullet or pellet can reach out. That's why I like the first way best. If you think it's necessary, you might want to set up a few demonstrations of what it looks like when a pellet hits something. Rotten fruit is good for this, as are plastic milk jugs filled with water dyed red.

Make the students repeat the safety rules, and let THEM discuss what each rule means. To make sure every student participates in the discussion, to hold it in a setting that is as informal as possible, while still maintaining control over the class. Then, demonstrate what an infraction of the rule looks like. In the beginning, some students will get the idea right off, but some will require more processing time before they start responding to the infraction. The goal is for every shooter to respond to an unsafe act without thinking about it. For example, I have found myself shouting, "Cease fire" at airgun shows when someone dry-fires a gun indoors. I was as surprised as those around me, but the shooter got the message.

Testing without the formal structure
You can test the students on all the safety rules by committing infractions during the rest of the training. This is an old training tip, and it's a far better method than a formal paper or memory regurgitation test. However, once again, your students will not all respond at the same speed. You'll have a bright young girl who is as quick on the draw as Wyatt Earp, and there will be a quiet thoughtful boy who seems to be a half-second behind everyone else. You must find a way to test every student without embarrassing any of them.

Never stop testing the safety rules!
Continue to throw in a careless act from time to time during the rest of the training. The students will become so immersed in the shooting safety rules that they will surprise you someday. I have seen children shooters catching coaches and officials in unsafe acts at public events. I've been caught, myself. When the shooter knows the rules to that level, you have succeeded as an instructor.

Teaching shooters to use sights
This is the first lesson in training someone how to shoot. Guns are not required for this lesson, so you can even work it into a demonstration class held in a place that's inappropriate for actual shooting! I learned this in the NRA introductory class I took almost 50 years ago, and we practiced it for three successive weeks before ever shooting a gun. As a result, all the bullets from the first-time shooters landed somewhere inside the black bullseye!

The triangulation method
This method uses a flat stick (such as a yardstick), a chair for the instructor to sit on, two cardboard boxes, a target, a piece of paper and a lead pencil. An instructor is needed for each student. First, a sturdy set of paper sights is attached to the flat stick. You can also use real sights taped to the stick, but the front sight may have to be raised up on a block to align properly.

The sight trainer is simple and inexpensive to make.

Notice that we made an aperture rear sight. The shooters in formal training programs will be shooting with aperture sights, so it's important to not confuse them during training. Also, an aperture is MUCH more precise than any other open sight.

In the next lesson, I'll tell you how this training method works.

Friday, July 28, 2006

Colt M1911A1 Tactical: Part 2
Another action pistol from Umarex

by B.B. Pelletier

Today, we'll look at the performance of this pistol. It has a 5" barrel, so we expect it to be in the 400-425 f.p.s. region with lighter lead pellets. I'm interested in a pellet that shoots as accurately as possible.

Make mine wadcutters
All the Umarex action pistols are .177 caliber only. I use wadcutter pellets exclusively because the low velocity means the pellets will try to tear the target paper and wadcutters don't do that at the velocity these airguns can generate. If I were shooting action targets , I'd want accuracy but the shape of the nose would be less important. My choices for the Colt M1911A1 Tactical are Gamo Match, JSB Match Diabolo (pistol), RWS Diabolo Basic, RWS Club, Crosman Wadcutters, Crosman Premier Super Match and RWS Hobby pellets. I chose these on the basis of pellet shape and price. An action-pistol shooter is going to shoot a lot, so price has to be a factor...the same as accuracy.

Velocity and number of shots per powerlet
I chronographed the pistol with three different wadcutters to give you a good feel for the gun's potential. From a fresh powerlet, Crosman Super Match averaged 397 f.p.s., with a spread of 24 f.p.s. and a high of 410. RWS Hobby averaged 416 with a spread of 27 f.p.s. and a high of 430. Gamo Match averaged 408 f.p.s. with a spread of 10 f.p.s. and a high of 414. This pistol gave over 60 good shots per powerlet - a big suprise, because I only saw 45 good shots from the Walther CP88 Tactical!

Accuracy was best with Gamo Match, by a wide margin. With a careful hold, they will give 1" 5-shot groups or better at 25 feet. I feel they are capable of even a little better, like 3/4", but I didn't see it. Crosman Super Match pellets were second, and, being smaller, they loaded easiest of all. All other pellets have to be pressed into the magazine with a tool to get the skirts in all the way. A pellet seater works well for this. And RWS Hobbys gave surprisingly large groups - in the 1.5" range.

Adjusting the dot sight
The sight adjustments on the Walther MDS sight are backwards. Turn TOWARD the right to move the group left, and so on. This is in line with German target sights in general, and opposite how most of the rest of the world marks sights.

The grip safety on an Umarex Colt pistol has always been a bit "clicky" compared to the firearm. I mean, you can feel a click in your hand when it takes the gun off safety. The test gun's grip safety was very noticable. The single-action trigger-pull, however, is as crisp as I have come to expect on this model. A couple weeks ago, I commented on the nice trigger on the new Walther CP88 Tactical. That trigger broke at 6 lbs., and I liked it. Well, the trigger on this Colt breaks at 3 lbs., 4 oz. and is just as crisp! I can do some good shooting with a trigger like this!

The Colt M1911A1 is my favorite of all the Umarex pistols. Only the S&W 586 shoots better for me. This tactical version has a great dot sight that really enhances the gun's performance. If you've been wondering which Umarex to get, I'd suggest one of these Colts.

Thursday, July 27, 2006

Colt M1911A1 Tactical
Another action pistol from Umarex

by B.B. Pelletier

The 1911 Colt semiautomatic pistol is a handful! I used to swear it couldn't hit a barn wall if the shooter was on the inside, but then I met a member of the 2600 club (NRA High Master rating) who taught me how to shoot the .45. After that, I knew what millions of shooters have learned - the M1911A1 Colt is one of the all-time best handguns ever made.

What's good about it?
Many of the reasons for the firearm's greatness do not transfer to a pellet pistol. The .45 ACP (Automatic Colt Pistol) is one of the top manstoppers in military history; the 1911 action is virtually unstoppable in the field and maintenance is a breeze. But the accuracy, the grip and the training value of the Colt M1911A1 Tactical pistol are worthy reasons for buying one.

What makes it different?
All the pistols Umarex makes have similar features and performance. Most use the 8-shot circular magazines, all are powered by 12-gram CO2 cartridges, and all have similar accuracy, velocity and the ability to mount accessories. What makes the Colt M1911A1 different is that the design of the gun copies the original Colt pattern so faithfully. A shooter can actually derive training value from this pellet pistol because it mimics the weight, the sights and the special hold required for the firearm. It has a real functioning grip safety that I tested. It works! Unlike the firearm, the hammer falls on the pellet pistol when the trigger is pulled without the grip safety being depressed, but the gun does not discharge CO2.

This is an 8-shot repeater that fires with each pull of the double-action trigger. The firearm has a single-action trigger, and the recoiling slide cocks the hammer for each new shot besides loading the chamber with a fresh round. The pellet pistol has no recoiling slide, so a double-action trigger is required for rapid fire capability. The trigger-pull is very light and smooth - especially after you get used to it. It makes the rapid engagement of targets such as Daisy's Shatterblast as fun as a practical pistol match. That's where Walther's Multi Dot Sight really shines.

Walther Multi Dot Sight (MDS)
The MDS is different than other dot sights, in that you can adjust the SIZE of the dot as well as the brightness - that's the "multi" in Multi Dot. Shooters find that different lighting situations call for flexibility in the illumination of the dot, and the MDS is one of the most flexible sights in its price range. It comes already mounted on the pistol, so everything is ready to shoot when you get it. I found this sight very useful on the different ranges where I tested the Colt. Even in bright afternoon summer sun, the dot was always visible outside. As an acid test, I sighted on yellow flowers and bright clouds in a sunny sky and, with the largest dot set on the brightest intensity, I could still see it easily. This sight is part of what makes this a tactical gun.

There is the adjustment for dot size under the MDS module. It's a feature not often found in this price range.

It really doesn't silence the gun, but the tactical silencer spins on the muzzle, just like the real thing. It's quite light and does not change the balance much. The foam-lined hard case is cut to house the silenced gun with dot sight mounted without any disassembly.

Tomorrow, I'll give you some performance data and discuss shooting.

Wednesday, July 26, 2006

Sighting-in a scope
Don't get carried away!

by B.B. Pelletier

Sighting-in a scope must be frightening to many shooters because, of all the technical questions we get, a large percentage deal with problem scopes. Many of the problems can be traced to the fact that they haven't been sighted-in correctly.

Problem 1. Sight-in distance IS NOT YOUR CHOICE!
You can choose any distance you like to sight-in your scope, so what can I be saying? Just this - yes you CAN choose ANY distance at which to sight-in, but you aren't going to like more than a very limited selection of distances. You will be frustrated if you sight-in at ALL OTHER distances, then I will get a confused comment like this:

B.B. I sighted-in my rifle to hit dead-on at 40 yards, but at every other distance the pellet shoots below the aim point! I can understand when it does that at ranges farther than 40 yards, but why does it also shoot lower at 20 yards? CONFUSED

Dear Confused,

Your gun shoots lower at all other distances because THAT'S THE WAY YOU SIGHTED IT IN!! If you want your car to stop within 25 feet of applying the brakes, don't slam them on at 70 mph!

The laws of physics are more unforgiving than the laws of man.

When your pellet leaves the muzzle, IT IMMEDIATELY STARTS FALLING TOWARD THE GROUND! It doesn't rise up above the bore and then fall, like the drawings seem to show. It falls instantly, and it falls at the same rate as a pellet dropped from the same height as the muzzle. If the bore is parallel to the earth and the shot and dropped pellets both take off at the same time, they will both hit the ground at the same time. The shot pellet will hit some distance from the gun because of its velocity.

To compensate for the drop of the pellet when we sight-in, we point our scopes slightly down toward the ground, so the exiting pellet will SEEM to rise above the line of sight. That is why we speak of TWO distances at which the pellet will be dead-on with the crosshairs. I discussed this in an earlier posting about sight-in distances (At what range should you zero your scope?).

Here is where physics steps in. Those two distances are determined by the velocity of the pellet AND the rate at which it slows down because of drag. With modern adult airguns all shooting at pretty similar velocities (750-950 f.p.s.) and with diabolo pellets being so similar, the choices of aim points is limited - IF YOU WANT TWO AIM POINTS, THAT IS.

If you insist on sighting-in at 40 yards, go ahead. But don't ask me why the pellet shoots lower at all other distances. You have selected the spot in the trajectory curve where that will happen. Actually, given a spread of velocities, there is a short span of distances, all hovering around 37-45 yards, at which this will happen.

Yeah, well, B.B., I want to sight-in at six yards, because that's the distance from my back door to the garbage cans, and we have problems with raccoons. Now, can you tell me why my pellet is so much higher at all other distances? I mean, until I get way out past 50 yards, my pellet is in orbit! Please tell me how to get it back on target at 30 yards, because that's where the bird feeder is.


[B.B. has left the building - escorted by two nice men in white coats.]

Tuesday, July 25, 2006

Spring gun tuning: Part 8
Disassembly of other spring guns (contd)

Spring gun tuning: Part 1
Spring gun tuning: Part 2 - Building a mainspring compressor
Spring gun tuning: Part 3 - Mainspring compressor continued
Spring gun tuning: Part 4 - Let's disassemble a gun!
Spring gun tuning: Part 5 - Powerplant disassembly
Spring gun tuning: Part 6 - Disassembly completed
Spring gun tuning: Part 7 - Disassembly of other spring guns

by B.B. Pelletier

Today, I'll discuss sidelevers, underlevers and anti-beartrap mechanisms. All these things are additions to what is basically the same mechanism we looked at in the breakbarrel Beeman R1. In fact, there are some Walther target rifles that are breakbarrels with the same type of anti-beartrap mechanisms as the underlever HW77. So, what you already know about spring powerplant disassembly still applies.

Both sidelevers and underlevers usually employ a sliding compression chamber that moves the piston into the cocked position. The exception is any gun with a different type of breech, like BSA's rotary breech (the Gamo CF-X has one), all taploaders and guns that use a flip-up transfer port to gain access to the breech, like the Diana 46 and the Webley Eclipse.

When a gun has a sliding compression chamber, disconnect the cocking mechanism from the sliding chamber and remove it from the gun. In some cases, certain underlevers are held on by rivets, so just take off the connecting link.

The Diana 48 and 52 sidelevers are fairly easy to work on. Pop the sidelever away from the receiver and remove the pins that hold it to the cocking link and receiver. Notice that the cocking link is slightly bent. The bend goes against the receiver to keep tension on the sidelever when it is stored. Leave the cocking link attached to the sliding chamber until the mainspring is out. Finally, remove the ratchet safety mechanism located under the receiver.

You can now install the receiver in your compressor, put some tension on the end cap and remove the two crosspins we discussed yesterday. Back off the tension on the compressor and the trigger block will be pushed out of the gun, followed by the mainspring. The piston can be removed now, too.

The sliding chamber can now be slid to access the Allen screw that holds the cocking link. Then, the chamber will come out of the tube as well. Other sidelevers are just variations of this theme.

Think of an underlever as a sidelever turned 90 degrees, because that's all it is. Look at the TX200.

The TX200 cocking link looks similar to the R1 link. This link is connected to the sliding compression chamber that houses the piston. It must slide back to cock the gun, then forward to act as a compression chamber when the piston springs forward. Notice the large vertical bolt (extreme right) that holds the TX powerplant together.

The cocking link connects to the sliding chamber.

Anti-beartrap devices
Most anti-beartrap devices are simple, like the ratchet on the RWS 48/52, but Weihrauch uses a sliding steel bar that connects the cocking lever to the trigger.

The big bolt in front of the HW97 trigger doesn't hold the mainspring. It's a bushing for the stock screw and holds down the anti-beartrap mechanism (small spring).

The HW97 anti-beartrap mechanism is disassembled.

That's the end of powerplant disassembly. Next, I'll show you how to tune a gun. The mainspring compressor will be shown in greater detail in that segment.

Monday, July 24, 2006

Spring gun tuning: Part 7
Disassembly of other spring guns

Spring gun tuning: Part 1
Spring gun tuning: Part 2 - Building a mainspring compressor
Spring gun tuning: Part 3 - Mainspring compressor continued
Spring gun tuning: Part 4 - Let's disassemble a gun!
Spring gun tuning: Part 5 - Powerplant disassembly
Spring gun tuning: Part 6 - Disassembly completed

by B.B. Pelletier

Thanks for being patient. Today, I'll show the other common types of spring gun disassemblies. Few other airguns have the screw-in end cap like Weihrauch (except for many Beeman R-series guns, of course); but, in the 1950s, Anschütz made a military model called the Hakim and a civilian version of the same gun and both had a screw-in end cap.

Stock disassembly
When disassembling the action from the stock, you'll find both triggerguard screws don't attach to the action on some rifles. Usually, the rear screw is just a wood screw. When you find this, just leave it in place. Some modern guns, such as the Gamo CF-X, have only a single stock screw in the triggerguard area. Because the stock is a one-piece molded affair, the triggerguard doesn't have to be held on, and this is obviously just the rear action screw.

Study the action
Something has to hold the powerful mainspring in place. If you study the action long enough, it becomes clear what that is. There are two very common methods of holding a spring gun powerplant assembly inside the mainspring tube - the vertical bolt and the crosspin.

Vertical bolt
This type is found on the FWB 124, the TX 200 and others. A large bolt comes up from the bottom of the mainspring tube and holds either the trigger housing or a sheetmetal sleeve that restrains the mainspring. Some guns, such as the 124, come apart in pieces, and you have to catch several small parts and springs as the assembly backs out of the mainspring tube. Others, such as the TX200, are modular. The TX trigger unit is held in place by the same two pins I showed you in the R1. The end cap is held in by the bolt.

A large vertical bolt holds the FWB 124 together

Before you start to remove the vertical bolt, try to relieve the tension the mainspring is putting on it. There's usually something in the end of the mainspring tube that can be pushed by your mainspring compressor to do this. This is where you'll need to make various pusher blocks to augment your compressor. If you look at the R1 disassembly, you'll see I put folded cardboard inside the headstock cup to push on the end cap.

The other mainspring restraining method is with crosspins, and two is the normal number. Diana has long been using two crosspins on their rifles. The older models had trigger assemblies that were not constrained by anything more than the mainspring tube. When disassembling these guns, watch for trigger parts that try to fly everywhere. Reassembly of these guns is an art that must be learned and practiced often. Newer guns have unitized trigger assemblies that contain all the little parts. These guns are much easier to work on, except for the automatic safety bar that has to be fiddled in between the two crosspins.

This vintage Diana 27 has two pins at the very rear of the spring tube. Modern pins are farther forward than this.

Often, one crosspin will have all the tension on it, and the other is just a backup. Dianas are like that. In older Webley guns, one crosspin is held by a grub screw that is hard to locate. If pins don't drift out easily, look for things like this.

Tomorrow, I'll write about underlevers, sidelevers and anti-beartrap mechanisms.

Friday, July 21, 2006

The Logun Domin8tor: Part 2
The rest of the story

Read the first part of this review (The Logun Domin8tor: Part 1/A light hunting rifle worth consideration).

by B.B. Pelletier

I'll finish looking at the Logun Domin8tor today. Let's start at the range.

Getting ready
It took 60 pump strokes to fill the rifle from 2,000 psi to 3,000 psi. On high power, you get about 18-20 shots. That's about three pump strokes per shot. While filling the gun, I noticed that the fill port is always open. That's unacceptable for a hunting airgun; however, the solution is simple. Just cover the fill port with something that prevents dirt and debris from entering the port. If dirt is blown into the reservoir during a fill, it could cause a leak if it gets onto the surface of the valve. Keep the fill port as clean as possible!

The bolt and magazine pin are both withdrawn.

Loading the magazine
Nothing could be easier! Pellets seem to drop into the funnel-shaped chamber openings in the circular magazine. The Logun Domin8tor is made by FX of Sweden, so their magazines fit the gun. I found JSB Exacts especially easy to load. Be sure to inspect the pellet skirts before you load them, or have a ballpoint pen handy to pop out the bad ones.

The Logun Domin8tor stock has enough drop at the butt to feel comfortable shooting off a bench. When the rifle fires, a strong puff of air is felt on the left hand. It's coming from the magazine slot and is completely normal. The magazine rotates counterclockwise when the bolt works, and there's an inspection slot in the right side of the receiver so you can see if a pellet is available for the next shot.

Other features
There's a pressure gauge under the stock to tell you when its time to refill. There's also a Picatinny rail molded into the bottom of the synthetic stock to accept a bipod. If you own a silencer, you can attach it to the muzzle. It's threaded on the outside with 1/2" fine threads. My own .22 rimfire silencer has 1/2" by 28 threads that are common on firearm silencers but too coarse to fit the Logun Domin8tor. Of course I could have an adapter made. The 19.7" barrel is entirely free-floated.

I shot on two different days. One day there were breezes gusting to 10 m.p.h.; the other day was dead calm. The results from both days were similar. On high power the best 50-yard 5-shot group of JSB Exacts measured 0.821". The average JSB group was just under nine-tenths of an inch.

Best 50-yard group of JSBs measured 0.821".

On both medium and low power, the groups opened to 1.25" to 1.5". I did try shooting Crosman Premiers, but the groups were much larger so I didn't pursue them.

With 20.5-grain Logun Penetrators (shot only on high power), the best group at 50 yards was 1.057". One group with that pellet was 1.40" but most were close to the one-inch mark.

The bottom line
The Logun Domin8tor is a lightweight, powerful rifle that should be considered by hunters. You'll like the fast cocking action, the built-in pressure gauge, the power adjuster and the 8 quick shots.

Thursday, July 20, 2006

The Logun Domin8tor: Part 1
A light hunting rifle worth consideration

by B.B. Pelletier

Logun's new Domin8tor is a lightweight, powerful new hunting rifle. Shown here with a Bushnell 6-18x Trophy scope.

I've been shooting a .22 caliber Logun Domin8tor for the past few weeks. It has some good points - and some great points - that I'll share with you today. By the way, this was a poor choice for a model name, since the Walther Dominator has already been on the market for 4 years. Do not confuse the two rifles.

Biathlon-style "flipper" cocking
The first thing I had to get used to was the biathlon flipper that cocks the gun. On the new gun, it was stiff and sticky. After 100 rounds had been fired, it smoothed out and became easy to operate. Cocking the rifle is easy: your shooting hand pulls back on a sidelever that's located where a conventional bolt would be. It's called a flipper because, on a biathlon firearm, all the shooter has to do is flip his shooting hand backward to cock and reload. On the Logun Domin8tor, however, you must close the bolt positively. Don't rely on the flipper return spring, or you'll get misfires that lead to double feeds.

The flipper handle flips back to cock the rifle, and a spring returns it to the forward position. You must make certain the bolt is locked closed or the pellet will not fire well. Notice the circular magazine sticking up above the receiver.

One final comment on the bolt. It loads very smoothly. You probably won't feel resistance when the pellet enters the breech.

Very light!
This rifle weighs just over 5 lbs., making it one of the lightest precharged rifles around. Only a few Falcons are lighter. The adjustable trigger is very crisp and positive, breaking at 1 lb., 4 oz., on the rifle I've been shooting. It's a delight to use!

The magazine
First of all, the 8-shot circular magazine sticks up above the receiver, so you must use two-piece scope mounts. Second, it has pellet length limits that can just accommodate a Beeman Kodiak (I tested the .22 caliber rifle). When you release the mag from the receiver to load it, be ready to catch it - as a spring throws it from the gun. It fits the receiver only one way, so there will be no confusion about which side the pellet goes in - assuming you know the pellets will eventually exit the muzzle!

Power adjustment
The Logun Domin8tor has adjustable power with three settings. The lever to select which power you want is on the left side of the action. It is EXTREMELY HARD to move until it has been cycled several times. Then, it loosens up, but it becomes hard to move again as the rifle sits between sessions. My advice is to plan what you want to do beforehand and set the power then. This problem will be especially noticeable in cold weather.

A detent holds the power adjustment lever in each position. This is set on high.

The three levels are very well planned for most shooting. On high power, I got an average of 914 f.p.s. with 15.8-grain JSB Exacts, which works out to an energy of 29.32 foot-pounds. I got about 18 shots from a charge on that setting. The rifle was clearly most accurate at that setting, too. I also tried some 20.5-grain Logun Penetrators, which gave an average of 792 f.p.s., but they varied widely in velocity. The spread for 8 shots was 68 f.p.s., and they were not quite as accurate as the JSBs.

On the medium-power setting with the same JSB pellet I got an average of 769, which is a muzzle energy of 20.75 foot-pounds. Accuracy at 50 yards was not quite as good. On low power, the average was 635 f.p.s. for an energy of 14.15 foot-pounds. Accuracy was average at long range.

Tomorrow, I'll finish this report with a look at some targets and some other features of the gun.

Wednesday, July 19, 2006

Walther CP99

by B.B. Pelletier

I was asked for a report on the Walther CP99 several times, the last being in the comments to the CP88 report. We have a reader who calls himself (I only assume it's a man) CP99 Fan, but there are several others who are also interested in this airgun.

Modern gun in all respects
Walther doesn't tell me their secrets; but, if I had to guess, I'd say the P99 was developed to be the law enforcement sidearm that the P88 never quite became. Both firearms shoot the 9x19mm Parabellum round that is currently so popular among law enforcement agencies around the world. Recoil isn't an issue, but magazine capacity, ergonomics and manufacturing costs are, and the P99 excels in all but mag. cap., where it is equal. And the ruggedness of the newer polymer-framed P99 is quickly becoming the stuff of legends. But, we're interested in the pellet pistols, not the firearms.

No. 1 advantage of the CP99
Like the firearm, the CP99 comes with three different-sized backstraps to adjust the gun to the size of your hand. Having the correct backstrap fitted changes the natural "pointability" of the gun from that of a two by four to something more like a Single-Action Army or even a Luger. As practical as Walther's P38 was, it robbed the soldier of a natural-pointing handgun. Their pocket pistols, such as the PPK, still point well, and their later service-sized sidearms handled better than the P38, but they were not world-beaters.

The CP99 comes with three different backstraps, so the shooter can make it fit his hand. Just drift one pin from the frame to change backstraps!

The P88 was the most recent Walther service pistol and was a wonderful gun that was developed for U.S. Army trials to replace the M1911A1. It proved too expensive to make, but it was a wonderful natural-pointing pistol. Well, the P99 went one step farther by offering a gun the shooter can size to his own hand.

Better fit than the CP88
I like the CP88 better than the CP99, but that's just my personal taste. The CP99 does fit my hand better, and a P99 would undoubtedly make a better defense weapon for that reason alone. I set up my CP99 to get the gun pointing where I looked and was able to shoot accurately from the hip. At distances up to about 20 feet, this is how I would engage targets most times.

In all other respects, it's an UMAREX air pistol!
These guns are so much alike under the skin that you can pretty much extrapolate their performance specs from one gun to another. If you have a 4" barrel, expect velocities around 350-400 f.p.s. If the barrel is 6", the velocity will top 400, going perhaps to 425. I used to think the 4" guns could shoot no better than a 1-1/8" 5-shot group at 25 feet, but using the Walther red dot sight on the CP88 Tactical demonstrated that the gun is capable of a little better accuracy at that distance - perhaps one inch. You should get the same 45 shots or so from a powerlet before needing to change.

It comes down to personal taste, once again. The P99 is now James Bond's service sidearm; so if that's your inclination, you're in good company!

Tuesday, July 18, 2006

Jury finds airgun silencer illegal

by B.B. Pelletier

Michael A. Crooker was found guilty, last Wednesday, of illegally making a silencer. He faces a mandatory sentence of 15 years in federal prison. The case was followed by Massachusets newspaper The Republican.

The actual charge was "causing a firearm to travel in interstate commerce." You see, under federal law, a silencer is considered to be a firearm.

The law
From U.S. Code, Title 18, Part 1, Chapter 44, Section 921 Definitions:

(3) The term "firearm" means

(A) any weapon (including a starter gun) which will or is designed to or may readily be converted to expel a projectile by the action of an explosive;

(B) the frame or receiver of any such weapon;

(C) any firearm muffler or firearm silencer; or

(D) any destructive device. Such term does not include an antique firearm.

(24) The terms "firearm silencer" and "firearm muffler" mean any device for silencing, muffling, or diminishing the report of a portable firearm, including and combination of parts, designed or redesigned, and intended for use in assembling or fabricating a firearm silencer or firearm muffler, and any part intended only for use in such assembly or fabrication.

Mr. Crooker made the silencer for a Big Bore 909 air rifle. Then, he sold the rifle to an Ohio man in 2004 and shipped both it and the silencer by mail to the buyer. The package was intercepted enroute by government authorities and the silencer was tested by BATF&E by installing it on a firearm, where it muffled the report. That is the test that determines whether or not something is a silencer.

The jury
The jurors deliberated 10 hours before reaching their verdict. They came back to the judge one time, asking for a better definition of a silencer (join the club!), but the judge told them they would have to go by the definition in the law as it is written.

In his closing argument, defense attorney Vincint A. Bongiorni told the jury that he defied them to find any evidence that his client had actual knowledge that the silencer he made would work on a firearm. That was probably the wrong thing to say, because Mr. Crooker was already a convicted felon with a history of skirting the law.

What does this outcome mean?
This verdict will probably serve to embolden the BATF&E, which has many cases that are waiting for this kind of result. The fact that this was a jury trial is very significant, because the judge had ruled that the prosecutor had to prove the INTENT of Mr. Crooker to make a firearm silencer. The jury obviously concluded that he had that intent. If this case had been decided by this judge, alone, it is doubtful that the same verdict would have been reached.

In my opinion, the future of silencers that are not part of the integral design of the airgun is in jeopardy. My thanks to Tom Gaylord's blog, All About Airguns, for alerting me to this news.

Monday, July 17, 2006

Spring gun tuning: Part 6
Disassembly completed

Spring gun tuning: Part 1
Spring gun tuning: Part 2 - Building a mainspring compressor
Spring gun tuning: Part 3 - Mainspring compressor continued
Spring gun tuning: Part 4 - Let's disassemble a gun!
Spring gun tuning: Part 5 - Powerplant disassembly

by B.B. Pelletier

Now, the pivot bolt can be unscrewed from the left side of the compression/mainspring tube.

The pivot bolt has been removed from the left side of the compression/mainspring tube. The large washer sitting on the base block next to the bolt hole is one of two thrust washers that fit between the base block and the sides of the compression/mainspring tube. They allow the base block to pivot freely without galling the compression/mainspring tube.

Pay attention here!
Notice the large thrust washer laying on the base block. It is very thin, but it allows the base block to pivot without scraping against the compression/mainspring tube. You can see where it wore some of the finish from the base block around the pivot bolt hole. Lubricating these washers (there is another one on the other side of the base block) with a heavy-duty lube is very important to a smooth cocking cycle. Also, lubricate the pivot bolt, itself, for the same reason. I use a moly-impregnated grease, because molybdenum disulfide particles bond with the steel and continue to lubricate the region for a long time. Moly is one of the slickest substances known.

Notice that the cocking link is riveted to the base block. It never needs to come off unless there's a problem. As of this moment, the cocking link is still attached to the piston by a sliding link. It is quite easy to now separate the barrel cocking link from the sliding link by just moving the barrel away from the compression/mainspring tube.

The cocking link has been separated from the sliding link in the piston. The sliding link is seen at 7 o'clock to the center of this photo.

How to get the piston out
You can see an enlargement in the cocking slot under the cocking link in the picture. The sliding link can be slid up to this enlargement and drop free of the gun, making the piston free to come out. The piston will require some coaxing, because it is really tight in the compression/mainspring tube. Use a screwdriver blade through the cocking slot to gently shove the piston to the rear of the tube.

The edges around the cocking slot are razor-sharp, and I am not exaggerating. Working around the slot to remove the piston, you can easily slice your fingers. Please be careful. Also, the piston has a cocking slot in it that's nearly as sharp. Handle these parts as though they were knives.

The powerplant consists of the piston, mainspring and spring guide. The end cap is aligned with the spring guide exactly as it was inside the gun (look at the picture of the end cap when it came loose from the mainspring tube).

This disassembly took about 30 minutes. The first time you do it with a brand new R1 should take 2 hours. Other spring guns are not as easy to disassemble and will take longer. I'll stop here today. I will return in a few days to discuss the other ways guns come apart. I want to do a few other reports before then so we don't bore anybody.

Friday, July 14, 2006

Spring gun tuning: Part 5
Powerplant disassembly

Spring gun tuning: Part 1
Spring gun tuning: Part 2 - Building a mainspring compressor
Spring gun tuning: Part 3 - Mainspring compressor continued
Spring gun tuning: Part 4 - Let's disassemble a gun!

by B.B. Pelletier

First, the trigger comes out by drifting two crosspins from the left. The safety is spring-loaded and will be released when the trigger unit drops free.

Two pins are drifted out and the Rekord trigger is free.

Here's the trigger with the crosspins, the safety and its spring.

Unscrew the end cap
The end cap is the reason Weihrauch spring rifles are much easier to disassemble. It holds the mainspring in the gun under compression. It simply unscrews from the spring tube. The first time you take it off it may be hard to start, so insert a wrench handle in the slot where the Rekord trigger was and bump it from the side. Mine's been off before so it simply unscrews.

The end cap simply unscrews! The action is not yet in the compressor because the end cap is still restraining the spring, however, at this point, it goes in!

This is where other spring guns cause problems. In a later posting, I'll discuss several of the other common ways of holding the mainspring in the rifle.

The end cap is out and the mainspring is coming out of the tube. This is where you really need to keep the gun under control, and the compressor does that for you.

With the end cap out, I simply back off tension until the mainspring relaxes and I can safely remove the action from the compressor. Now, the mainspring and spring guide will come out of the rifle, but not the piston! It's held in by the cocking link that's connected to the barrel (this is a breakbarrel, remember?).

The end cap is off, and the mainspring is out, but the piston is still connected to the barrel by the barrel link, shown here.

Separate the barrel from the spring tube to release the piston.
This involves removing the pivot bolt that serves as the barrel's axle when it breaks open. On Weihrauch rifles, there is a nut on the right side that's removed first.

The pivot nut looks like a large screw head. It has been removed from the bolt in this photo.

I'll finish disassembly in the next post.

Thursday, July 13, 2006

Spring gun tuning: Part 4
Let's disassemble a gun!

Spring gun tuning: Part 1
Spring gun tuning: Part 2 - Building a mainspring compressor
Spring gun tuning: Part 3 - Mainspring compressor continued

by B.B. Pelletier

Enough build-up. Today, the disassembly begins! I've selected a Beeman R1 to tune for you. That means I'm now going to get specific about parts and how they come off, but I will make provisions for other airguns, as well. What I can't do is provide complete disassembly instructions for every spring gun made because there isn't enough time and I haven't taken all of them apart. I'll provide general instructions for different categories of guns, and you'll have to be clever enough to follow along and to figure things out on your own.

Before you start
Is this a project you SHOULD do, or are you a person who goes halfway and quits? If the latter is the case, DON'T START! I will not assemble any basket cases for anyone, nor is Pyramyd Air responsible in any way for your actions. I am doing this series so those who want to learn about their spring gun powerplant - can. I make no guarantees to anyone about anything.

Make certain the gun is neither loaded nor cocked. You'll be sorry if you get the gun partly disassembled, only to discover that it's cocked. It can kill you if you don't handle it carefully, so take NO CHANCES.

Remove the action from the stock
The R1 has two forearm screws and two screws through the triggerguard. All four are removed, and the triggerguard comes off before the action is removed from the stock.

R1 action removed from stock. Sights have been removed.

B-Square's mainspring compressor is lightweight and very adjustable. Can you identify the headstock, bridge and tailstock?

The bridge uses five bolts to enclose the rifle's action and keep it from moving when the mainspring is decompressed. The bolts on top will pass over the action. I use a heavy leather belt around the gun to keep from scratching the metal.

Install the action in the mainspring compressor
I'm using a B-Square mainspring compressor, and the big thing with that one is to restrain the middle of the action. Since the bridge is different than the one found on homemade compressors, you have to spend a little time snugging the middle of the gun. Also, make sure you allow enough travel in the headstock so the mainspring can be decompressed all the way. If you don't, you'll have to assemble the gun again and adjust the compressor.

What if you have no idea how far the mainspring will travel to decompress? Well, that happens when taking apart a gun that's new to you. Don't trust what anyone tells you, because your gun may have an aftermarket spring that's a lot longer than they say. What I do is allow a maximum of five inches of headstock travel when I'm not familiar with a certain gun. The worst I have seen was about 4 inches of travel on factory FWB 124s (all of them) and also once on a tuned HW77.

Tomorrow, I'll put the rifle in the compressor and remove some parts!

Wednesday, July 12, 2006

Walther CP88 Tactical - part 3

Read the first part and the second part of my review of the Walther CP88 Tactical.

by B.B. Pelletier

The muzzle of the pistol is threaded for a screw-in silencer. As noted in the last report, this is not a real silencer - it's just for looks. In a curious turn of events, this silencer actually sharpens and magnifies the report! A flat pop becomes a sharp crack with the can screwed on.

Being a functional guy, I don't go for eye candy, but a lot of shooters do, and the CP88 Tactical pistol was designed for them. To their credit, Umarex cut the foam inside the CP88 Tactical's hard gun case to fit the gun with the silencer mounted, as well as a special spot for it when it's taken off.

Pistol comes in a hard case. Foam is cut to accept pistol with all accessories installed, plus a separate cutout for the silencer (it now holds the Allen wrenches, rear sight and clips).

The sweet trigger mentioned in the last report, plus the generous grip make this pistol a delight to shoot. I was glad I had loaded a bunch of Walther clips in the Speedloader report, because I went through them rather fast. I don't remember my first CP88 being quite as much fun to shoot as this one, and I'll attribute the difference to the trigger that I believe has gotten better over the years. I still prefer the M1911A1 trigger, because my hand fits that grip configuration better; but the physical performance of the CP88 trigger is probably just as nice.

The CP88 shocked the world with its realistic look when it first came out. Nothing has changed in that respect. This is still a pellet pistol that fools a lot of gun buffs. The weight, the feel of cold metal and the realistic finish all tell you this is the genuine article. Because it's made by Umarex - the parent of Walther, this REALLY IS a Walther pistol! Collectors need it to complete their roster of specimens from Ulm.

I got five-shot groups of 1" at 10 yards when shooting H&N Finale Match pellets. That's about 1/8" better than the other Umarex pistols with similar-length barrels, and I think I know why. Longer-barrelled pistols often give me tighter groups, a trait I must attribute to their longer sight radius, but the red dot on the CP88 Tactical does away with the sights altogether. The accuracy has probably always been there and it just took an optical sight to bring it to the surface. The regular rear sight blade is also provided, in case you want to revert back to the CP88 with open sights.

If you favor large 9mm service-type pistols, the CP88 Tactical is probably the gun for you.

Tuesday, July 11, 2006

Walther CP88 Tactical - part 2

by B.B. Pelletier

Read the first part of my review of the Walther CP88 Tactical

The temperature was 95 degrees. The first four Gamo Match pellets shot single-action through the chronograph registered an average of 392.7 f.p.s., with a high of 399.9 and a low of 383.8. The next four were fired double-action, with an average of 372.1, a high of 374.4 and a low of 369.0 That's with a fresh CO2 powerlet.

For the benefit of all you velocity freaks, I shot a clip of Gamo Raptors. Single-action averaged 461.1 f.p.s., with a high of 469.4 and a low of 454.8. Double-action got an average of 431.7 f.p.s., with a high of 437.7 and a low of 426.4.

So, shooting single-action nets a little higher velocity than double-action, which is normal on Umarex airguns. The rated velocity of 393 is right on the money, although I tested the gun on a very warm day. The higher numbers with Raptors should be considered a benefit, as we sure don't want manufacturers testing their guns with them and then using those numbers in advertising!

I got four clips of very powerful shots (32) and another 13 good shots for a total of 45 good shots from one powerlet. I expected a few more shots; but, for the velocity, 45 is fine.

What I like BEST about this pistol
What makes the CP88 Tactical a "tactical" model is the Walther red dot sight and a fake silencer/compensator. I unscrewed the fake can immediately, but the red dot sight is the best feature of this model. It's well-made and very clear with lots of features not seen on red dots in this price range. For starters, it has the popular picture window style instead of a conventional optical tube. When Bushnell pioneered this look, they charged $500 for the pleasure of their company - Walther charges you about $85.

Then, there's the switch that lets you enlarge the size of the dot! Most red dots get larger as the intensity of the light increases, but Walther keeps the intensity separate from the switch that enlarges the dot! That gives you more control of the sighting situation. This sight would be welcome on a firearm, as well as a pellet pistol.

The one drawback on the dot sight was that the elevation screw was mismarked, but that became evident the moment I adjusted it. The instructions in the dot sight manual that come with the gun were correct.

The trigger on this pistol is really good. On single-action, it breaks cleanly at 6 lbs. but feels like 4. Double-action goes off at 7.5 and is as smooth as a fine DAO firearm pistol. The blade is quite wide and smooth, and that probably contributes to the good feel.

The P88 firearm has a double-stack magazine, so the grip is very wide and full. That carries over to the pellet pistol, and it feels as large as a Colt .45 even though it's just a 9mm. That's probably what spelled the end for the firearm, but in a pellet pistol, who cares?

Not quite finished yet. Tomorrow for sure.

Monday, July 10, 2006

Walther CP88 Tactical

by B.B. Pelletier

We got a question last week about the CP88. The guy asked whether it was "worth it." I don't know how to answer that, because I don't have that guy's value system memorized. The best I can do is tell you how a gun performs and let you decide whether or not it's worth it. Today, I'll look at the new Walther CP88 Tactical.

CP88 was the FIRST pellet gun from Umarex!
I'll never forget when I first picked up a CP88. I said to myself, "They're going to sell a million of these," and I bought one of the first ones to come into the U.S. The gun is so realistic that I immediately went on a hunt for a 9mm P88 firearm to accompany it, but alas, they were already winding down production on that model.

What IS a CP88?
A CP88 is an 8-shot pellet pistol powered by CO2. It's actually a revolver disguised to look like a semiautomatic pistol, but Umarex made the double-action trigger so light and smooth that it's hard to tell from a real semiauto. The gun can be fired either double-action by pulling the trigger or single-action by cocking the hammer first. The gun is all metal with thin plastic grips, though walnut grips are available.

Inserting a new CO2 cartridge
Put the gun on safe. Pop the left grip panel off by pressing on the round button on the right rear of the triggerguard. You now see the cartridge in the grip frame. To release the old cartridge, pull down on what appears to be the front of the magazine lip, but it's actually a cleverly disguised lever. If the cartridge is spent, a small amount of gas will usually exhaust; if it was full, the amount of gas will be greater. Rotate the brass wheel under the CO2 cartridge until there is enough clearance to remove the cartridge.

Left grip is off, and the lever is lowered. Note that the brass adjustment screw is adjusted down.

CO2 powerlet is in, adjustment screw up and lever closed. Powerlet has been pierced. Replace left grip panel and shoot.

Slip in a fresh cartridge, and rotate the brass wheel until the cartridge is snug inside the grip. DON'T OVER-TIGHTEN THIS SCREW OR THE CARTRIDGE SEAL COULD BE DAMAGED! Now, move the lever back up to the closed position. Point the gun in a direction safe to shoot, take the safety off and pull the trigger. If there is no pop, the cartridge hasn't been pierced and you need to go through the procedure again to adjust the brass wheel tighter. When the gun fires with a pop, you are ready to load and shoot.

Loading an Umarex pistol
We also had a question about this, so I'm going to show the process in detail. First, put the gun on safe. To load a new clip, open the slide by pressing down on the latch located on the left side of the gun. The front of the slide is spring-loaded and wants to jump forward, so control it with your hand. If there is an empty clip inside, remove it. A loaded circular clip is dropped into the open pistol with the ratchet teeth to the rear. Close the slide and rotate the latch back to its starting position. The gun is now loaded.

First put the safety on.

Slide catch is rotated down, and slide pops forward.

Clip goes in opening with ratchet teeth to the rear. Close the slide and rotate the catch closed. The gun is loaded and ready to shoot.

The gun is now loaded with gas and pellets. Tomorrow I'll shoot it for you.

Friday, July 07, 2006

Airgun HELP!

by B.B. Pelletier

Many readers post ads for their airguns on old posts in this blog - where the same gun is reviewed. There's nothing wrong with that except that most people don't read those old posts, so your ad isn't seen by many people.

We also get a lot of inquiries about where to buy old guns and parts for them. Once again, these are placed on the bottom of old posts and don't get read by anyone except me. So, today, I'm taking the time to explain the resources available to readers.

Airgun shows
These are the best places to buy and sell those old airguns. They happen every year at the same time and are a wonderful resource if you're serious about airgunning.

Little Rock, Arkansas
Happens on the last weekend in April. This year's show is past, but there will probably be one next year. Look for collectible Daisys, Sheridans, Benjamins and Crosman guns. Parts, too. This year, a local airgunner unloaded a large collection of modern springers from 1970-2000. Most were like new in the box. He asked what he paid for them, so it was possible to buy a Diana 50 TO1 underlever for what you would have paid in 1988. For show details, contact

Baldwinsville, New York
This is an especially good show for Crosman guns and air canes. Held on the third Friday in July. There's still time to make it this year! Contact Larry Behling at
315-695-7133 or

Daisy Get-Together in Mason, Michigan
Meet the top Daisy collectors in the world! This is the place to find hard-to-get Daisys and other turn-of-the-century BB guns. Held on August 26 this year. Contact Bill Duimstra at 616-878-0306 or

Roanoke Airgun Expo in Roanoke, Virginia
Held the first Friday and Saturday in November. This is the big one. A genuine Austrian Girandoni military rifle sold for $3,500 at this show. BB gun collections have sold for over $40K! Expect to find ANYTHING at this show. Contact Fred Liady at fax 540-345-4210 or

Internet resources
Go here to Airgun Info and check it out. This site is sponsored by Pyramyd Air and lists dealers, repair stations, free classified ads and more. You really should bookmark this site.

Repair stations and parts
For pneumatic Crosman, Benjamin and Sheridan guns:
George Pena at or 512-863-2951.

For pneumatic and CO2 Crosman, Benjamin and Sheridan guns:
Rick Willnecker at or 717-382-1481.

For spring gun parts, new springs and seals, plus lead shot:
John Groenewold, PO Box 830, Mundelein, IL 60060-0830, or 847-566-2365

For vintage Daisy guns:
Jim Coplen, PO Box 7297, Rochester, MN 55903 or 507-281-2314
Jim Dry, Claremore, OK, 918-341-9104

For CO2 and pneumatic tunes:
Dave Gunter Airguns or 503-556-1439

That's a pretty exhaustive list of resources. Yes, there are other places, but these are the ones I know and trust.

Thursday, July 06, 2006

Check out the Diabolo Speedloader

by B.B. Pelletier

I'm surprised I've never reported on the Diabolo Speedloader. As many articles as I've written about Umarex pellet pistols, I've only mentioned it three times, and never done an in-depth look until today.

What IS a speedloader?
A speedloader is a tool to help you load the circular clips for certain repeating airguns. It organizes pellets and starts them into the clips. Another part of the speedloader pushes them all the way in - and you're done.

How it works
Step one is to place seven empty clips on the base of the speedloader, with their ratchet side up. Next, place the loading plate over the base. Two pins will align the plate so the holes in it are in line with the holes in the empty clips. Step three places a retaining ring around the loading plate, so pellets will remain on the plate when they are poured on it. Now, the speedloader is ready for pellets.

The loader base has short pins to align the clips.

The loading plate fits on top of the base, over two plastic pins.

A retaining ring slips over the loading plate.

Pour pellets onto the speedloader. Notice that some have already aligned with holes! The retaining ring keeps the pellets from falling off the loading plate as you move them around.

I moved the pellets with my finger until all fall into a hole. I removed the retaining ring, which created two wide notches, and pushed the leftover pellets back into the tin. You're ready to push the pellets into the clips with the pusher plate. Some pellets are higher than others because there are small variations.

Pushing the pellets into the clips
The pusher plate has pins that push all the pellets to the same depth. The base plate has very short pins to keep the pellets from going too far. Look at this photo of a Crosman 1077 speedloader to see the relationship of the parts.

This photo of the parts of a 1077/NightStalker speedloader illustrates how they work together.

Don't go for a speed record
The first few times I used a speedloader, I botched it pretty bad. I realized the instructions said it takes less than one minute to load seven clips, and I was timing myself! After I stopped doing that, the speedloader got a lot easier to use. It was made to load wadcutters, but domed and pointed pellets load the easiest. Not watching the clock is the real secret to this job.

This speedloader works only with Umarex clips (not the Daisy, Crosman or Gamo clips that look similar), and the larger speedloader works only with clips for the Crosman 1077 and NightStalker. If you shoot a lot of pellets through these guns, you need a speedloader!

Wednesday, July 05, 2006

What IS a good tuneup?

by B.B. Pelletier

As long as we're looking at tuneups, it might be good to discuss the goals of a good tuneup. So many times I've read the comments of beginning tuners, who haven't got an idea of what they are after except for greater velocity. I've been shooting spring-piston airguns for almost 30 years, and I think I can tell a good tune from a bad one. Perhaps reading this discussion will help some of our newer shooters set their sights on what is possible.

The spring-piston powerplant is the harshest type!
Compared to pneumatic or gas guns, spring guns vibrate, recoil and require lots of holding technique to shoot well. So, the chief goal of a spring gun tuneup should be to make the gun shoot smoother.

Anti-recoil is not the answer!
If you've never experienced a non-recoiling gun, you might think they're the solution to traditional spring gun problems. They do away with all recoil, which seems like a good thing until you actually shoot one and discover what is left behind. The vibration and the firing impulse is still there in most recoilless airguns. A Diana model 6 or 10 pistol may not kick, but you still feel the jolt when it fires. A Diana 75 rifle also has a jolt, as does an FWB 300. In fact, the 300 often has a bundle of vibration, besides. A Diana 54 is the same, with lots of jolt and some vibration when it fires. Even a handmade Whiscombe rifle, which is the gentlest of all recoilless airguns, still packs a good jolt on firing.

Therefore, the primary goal of a good spring gun tune is to eliminate the firing jolt and vibration. The recoil can remain, because, of the three forces, it turns out to be the least objectionable.

Tight tolerances remove vibration
The fit of the moving parts in a spring gun powerplant is what causes vibration. Also, things like a bent mainspring (see How long does a mainspring last? Part 1) or a bent spring guide can contribute to vibration. By making the clearance between moving parts the smallest space commensurate with good operation, you can remove much of the vibration.

Reduce the jolt by balancing the pellet to the powerplant
The other BIG trick is to use a pellet that moves at a time that prevents the piston from bouncing or slamming into the end of the compression cylinder. You can feel a good pellet by the LACK of firing impulse it has! Conversely, when a pellet makes a gun jolt, it's not a good idea to use it even if it's accurate. The ideal pellet will be both smooth-shooting AND accurate.

Power comes last
After you have smoothed the powerplant, you can look for more power. As long as more power doesn't make the gun harsher, it's okay. The goal for a spring gun tune should be smoothness, less recoil and power - in that order.

Accuracy never changes as these factors change. It's easier to shoot a smooth gun more accurately, so that might be an additional benefit.

Tuesday, July 04, 2006

Spring gun tuning: Part 3
Mainspring compressor continued

by B.B. Pelletier

Spring gun tuning: Part 1
Spring gun tuning: Part 2 - Building a mainspring compressor

Happy Birthday, USA!

Today, I'll finish the mainspring compressor with details, dimensions and important tidbits.

The plank
The plank has to be long enough to accommodate any spring gun held between the vise and the tailstock. I used two 2"x8" boards, one on top of the other, but the top one isn't as long as the bottom, which has to could accommodate the vise. Look at the side view to see what I mean. The bottom board is longest (mine is 58").

The view from the side shows how the vise fits on the plank.

The tailstock and bridge are both held to the plank by long bolts. I found it unnecessary to use nuts on the tailstock bolts because all the force was lateral. The nuts on the bridge bolts restrain the gun from moving in all directions. When the mainspring comes out of the gun, it can push in all directions.

The pusher cover
Make a wooden cap to pad the steel pusher ram of the vise. The wooden cover pushes against the end cap of the gun or against another pusher adapter that reaches inside a gun. For a BSA rifle, use a dowel to reach inside the mainspring tube. Cut a wide slot in the center to reach past a retaining pin. As you work on different airguns, you'll create special tools to accommodate them.

The bridge
The bridge is three pieces of wood attached in a U-shaped pattern. It covers the gun laying on the plank and is held to the plank by long bolts. Make it wide enough for any gun to fit through it. Use pieces of wood inside the bridge to shim the gun tight once the bridge has been tightened to the plank. If the plank is 8" wide, make the bridge almost as wide. Align the vertical attachment holes with the holes in the plank (see part 2).

The tailstock
Make the tailstock as wide as the plank. Stack three pieces of plank board to make the tailstock and position them with the edge of the grain toward the vise. The muzzle of the gun pushes against the tailstock, and the end grain cushions best.

The headstock/tailstock relationship
The headstock and tailstock accommodate a spring rifle action between them. When you disassemble the rifle, the headstock ram is pulled back (away from the tailstock) several inches to relax tension on the mainspring. Then FWB 124 and HW 77 need the most travel (about 4"), so factor that into your building plans. When you assemble those rifles, the ram must be allowed to travel the same distance in the other direction. It's bad when you almost get a rifle disassembled, only to discover that your compressor won't let you put it together because it doesn't have sufficient travel.

Monday, July 03, 2006

Spring gun tuning: Part 2
Building a mainspring compressor

by B.B. Pelletier

This is the most important tool a spring gun tuner owns. It may not be used for every job, but working without one when you need it is like walking a tightrope without a net. I now use a B-Square compressor, but for many years I used a homemade rig that did everything I asked of it. The plans for my compressor came from Tom Gaylord's Beeman R1 book. I've seen simpler compressors, but I've never seen one that was easier to make.

Mainsprings are under tension
To get maximum power from an airgun, the mainspring is usually under tension (compression). In modern spring guns, the trend is toward more compression than in the past. A few rifles such as the TX200 are under almost none - but they are the exception.

You can't contain it!
Never think you can contain the force of a mainspring. Eventually, you'll be able to do so with certain guns you have disassembled many times or even with certain gun models you may have learned very well; but the first time you work on a spring gun, you need to use a compressor.

Simple design
All a compressor does is restrain the rifle while relaxing (or decompressing) the mainspring with control. The task would be simple if all spring guns were built alike - but they aren't. I will address several different methods of gun design in a later posting. For now, just take my word that the compressor has to be very adaptable.

This compressor is built on a 2x8 piece of wood. All the parts attach to a plank.

The headstock, the bridge and the tailstock
The headstock contains the moving ram that compresses the mainspring. You can make a rugged one from a bench vise. There's really nothing to build! The vise is bolted to the plank and used in reverse. The tail of the vise puts tension on the end of the gun holding the mainspring.

The bridge is a tunnel through which the body of the gun passes. It keeps the body of the gun from moving sideways when the mainspring is under tension but not restrained by the gun.

The tailstock is a block of wood with the grain end exposed. The muzzle is pressed against it and the gun cannot move.

The bridge and tailstock are adjustable to accommodate different guns. They can also adjust for a gun that has the barrel on or off.

Here is the thousand-word picture. The bridge has a large hole running through it for the gun.

A great vise for a compressor. The tailstock has a long reach!

Tomorrow, I'll finish this project and have some details and dimensions for you.