Archive for August 2013
by Tom Gaylord, a.k.a. B.B. Pelletier
Today was supposed to be Part 2 of the report on the BSA Scorpion 1200 SE, but I had an accident (actually a stupident) last night that prevented me from completing the test. I was slicing open a roll of bullet grease for my sizer/lubricator, and I slipped and cut my hand deeply. Today, as I was pumping the Hill pump to fill the rifle for the test, the wound reopened and I had to stop. Because the BSA fills to 232 bar and has a proprietary fill probe, I use the Hill pump because I don’t want to change out my more common Foster adapter on my carbon fiber tank since it fills most of the PCPs I own. Proprietary fill couplings are relegated to the hand pump.
This is also going to delay the next report of the Hatsan AT P1 pistol and the Evanix Rainstorm 3D bullpup rifle, as both of those PCPs also have proprietary fill probes and, of course, none of them fit any other gun — nor do they fit the BSA rifle! So, the only PCP I can report on for a week or 2 will be the Benjamin Marauder because it has a standard Foster fill coupling.
Today, I want to address the issue that blog reader Beazer brought up the other day when I talked about calling shots and following through. He mentioned that with his heavy-recoiling gas spring rifle, which he calls Mr. Nasty, he cannot keep the crosshairs on the point of aim after the shot fires. He wondered what to do about it. Let me pull a quote from his comment that explains everything well.
… should my sight picture return to p.o.a. after all the dust settles? Asked another way, if my reticle winds up off target, but my shot is close to on target, is something wrong in my shot execution?
Several other readers made similar comments about recoiling firearms. Obviously, this was a point that I failed to make in that report. Today, I want to set things right and talk about the ideal shooting position.
Let’s say I’m shooting at a 100-yard target with the open sights on a bolt action O3-A3 Springfield military rifle. This rifle is caliber .30-06, and it does recoil significantly. Nobody can hold the sights on the point of aim while this gun recoils. What I was trying to say in the report is that at the last instant before the shot fires, you look at your aim point reference for calling your shot. Someone else said it better — I think it was Fred. He says he takes a “mental snapshot” of the sight picture just before the gun fires. That’s a great way of saying what has to happen. No one can hold so still that they always know where the shot will go, but experienced shooters do watch their sights so they know where the gun is at the instant it fires. That tells them where the shot is going, and that’s how you call the shot.
So, on the O3-A3, I’m watching the front sight blade through the rear peep aperture, and I note the instant that the big service rifle fires. Of course, I lose all track of the target and sight picture after that. But if I saw where the front blade was at the moment of cartridge ignition, I know what I need to know to determine where the bullet probably went.
But what about what Beazer asked? Should the rifle return to the aim point after firing? In an ideal world, I guess it should, and maybe that’s possible for pellet rifles and rimfires more than it is for powerful centerfire firearms. The big kickers, like my .30-06, are going to push you around some, so don’t be surprised if you aren’t on target after the dust settles.
Instead of looking at it that way, I would like to turn things around and look from a different perspective. I would like to talk about how you settle in before you take the shot.
When I’m on a benchrest, or even when I’m in a seated or standing-supported firing position, it takes time for me to settle-in properly. I keep adjusting things until the rifle is aimed at the target when I’m completely relaxed. Don’t get confused — I don’t necessarily mean that I’m holding the rifle loosely. If the gun is a pellet rifle, I’m probably holding it loosely; but if I’m shooting a hard-recoiling rifle like a .30-06, you can be sure that I have the butt tight against my shoulder and the thumb of my firing hand is positioned to not break my nose when it comes back at me in recoil! Cowboy Star Dad told us that he’s learned to hold his .22 Magnum rifle firmly for best results, so maybe it’s only pellet rifles that are held loosely.
When I settle in the first concern is to rest the rifle as straight as possible toward the target. I’m now talking about looking through the sights and centering the rifle using them. If I’m using a rifle rest, that’s what gets moved from side to side. If I’m resting the rifle on my hands or directly on a sandbag, I put the butt to my shoulder and sight through the sights, then move the bag or my hands to center the rifle. If the rifle is handheld, my elbows also determine where it points; so once the gross corrections are made with the rest, I begin to make small adjustments of the elbows.
The object is that when I hold the rifle, the sights are aligned with the target so that when I close my eyes and relax, the sights remain aligned as before. I actually do this sometimes — close my eyes, take a deep breath and let it out, then open my eyes and see where the sights are. If they’re not aligned as I want them to be, I make adjustments to the hold and do it again. This works for rifles that are loosely held and for those that are held tightly.
I haven’t mentioned elevation yet, but of course that’s just as important as right and left. If I’m shooting off a rest that has a vertical adjustment capability, it gets adjusted up and down until the front sight is perfectly aligned. If the rifle is handheld, I do the same thing with my grip and the sandbag under it, if there is one.
One more thing
There’s one last step to this hold. That’s to touch the trigger and make sure the rifle doesn’t move away from the target as it’s squeezed. Sometimes this final step is the place where that last little bit of muscle tension gets revealed and corrected.
Do this for every shot
I know it sounds anal, but I repeat this process for every shot. You may think that a .223 Remington cartridge doesn’t recoil much; and in an AR-15 rifle, it certainly doesn’t — but even that pipsqueak cartridge moves the rifle enough to warrant this kind of attention, shot after shot.
If you’ll settle in like this for every shot, you’ll find that your groups grow smaller and smaller. You may already be using the artillery hold, but this procedure is part of it. I haven’t talked about this very much until now; but if you read my R1 book, you’ll see that I give today’s settling-in procedure the same importance as the artillery hold. This is what allows for calling the shot and for following through.
What about handguns?
Everything I’ve said today applies to rifles, only. Is there anything equivalent for handguns? You bet there is! There’s enough material to warrant at least one whole report of its own if there’s any interest among you readers. Today, I wanted to remain with rifles because there was so much to explain that I didn’t want any distractions.
A simple test to demonstrate the hold
I have an idea. What if I shoot 3 groups at 25 yards with the same accurate spring rifle? My Beeman R8 seems like a good candidate. From past tests, we know that JSB Exact RS pellets are a good choice for that rifle. One group will be shot using the classic artillery hold and the settling-in procedure I described today. A second group will be shot using the artillery hold without settling-in. I’ll use my muscles to hold the rifle on target, but I’ll use the artillery hold. Then, I’ll shoot a third group while holding the rifle like a deer rifle — gripping the forearm and pistol grip tightly and pulling the butt firmly into my shoulder. I promise to try to shoot my absolute best with each position. One 10-shot group should show a difference if I’m right about this. Boy, will I be embarrassed if I’m not!
by Tom Gaylord, a.k.a. B.B. Pelletier
This test was done for blog reader GunFun1, who asked to see what effect barrel length has on velocity. Though it appears simple, this test took 2 days to conduct because of barrel changes and other sundry things. But what was learned far exceeded my hopes, so the effort it took was well worth it.
I tested with an AirForce Talon SS, which has the facility to accept interchangable barrels. All testing was done with the rifle in .22 caliber, which means every barrel used was that caliber. I used the factory-installed 12-inch Lothar Walther barrel, an optional 18-inch Lothar Walther barrel and an optional 24-inch Lothar Walther barrel.
I fired 5 shots at each power level with each barrel. I could have shot more; but since I know the stability of the Talon SS powerplant, it really wasn’t necessary. And fewer shots made the test go faster. After every power change, I fired one shot before testing to settle the valve at the new level. I know that’s necessary for the Talon SS. Other PCPs may have different techniques after making power adjustments — including no warmup shots at all. But the SS requires one shot after every power adjustment. After testing each barrel, I refilled the gun to 3,000 psi. The pressure remaining in the reservoir when I began each fill was about 2,600 psi. So for all shot,s the rifle was running right in the middle of the optimum power curve.
I started each test on the highest power, then dialed back as the test advanced. That meant that when I got back to power settings 6 and zero, the rifle was in the middle of the power curve and was at its most stable condition.
I used only a single type of pellet — the 14.3-grain Crosman Premier. Had I used additional pellets, there would have been different velocities. The relationships we’re looking for are revealed in this one pellet as well as if I’d tested greater numbers of pellets. There was no need to waste shots or air.
I filled the air tank to 3,000 psi, then shot 5 rounds on the highest power, then 5 at power setting 10, then another 5 at power setting 6 and finally the last 5 at power setting zero. After every power adjustment, one dry-fire shot was taken to set the valve at the new power setting.
First, let’s look at what happened with all 3 barrels at the maximum power setting. The 12-inch barrel gave an average 835 f.p.s. The 18-inch barrel averaged 921 f.p.s. and the 24-inch barrel averaged 1024 f.p.s. That’s all with the same powerplant, the same amount of air being used with each shot — in fact, everything was the same except for the length of the barrel. This is a clear demonstration of what a longer barrel can do for a precharged gun.
However, there’s one thing we need to note. The barrel I used for the 12-inch barrel is not the same 12-inch barrel that was used in the previous test of rifling twist rates. If you look back at that test, you’ll see that this same rifle shot a Premier pellet on power setting 10 (854 f.p.s.) faster that it did in this test (827 f.p.s.). The reason is probably due to small differences in the individual barrels — the smoothness and diameters of the bores and how well the backs of the barrels seal against the air valve in the reservoir. So, one 12-inch barrel can be different than another 12-inch barrel — even when they’re both produced by the same manufacturer! That’s worth noting. I used to see this all the time when I tested guns while I worked for AirForce, and now I’m showing you what I used to see. A lot of shooters don’t understand or even believe this can be possible. They think that one barrel must be exactly identical to another barrel of the same specifications made by the same manufacturer.
A second thing to note is the fact that the 12-inch barrel didn’t get much more from the maximum power setting than it did on power setting 10 (835 f.p.s. to 824 f.p.s.). In fact, that held true up through the 24-inch barrel, which tells me that power setting 10 is about as high as I need to go to get the most from this particular rifle’s powerplant. Other PCPs that have adjustable power will behave differently than this, but they’ll all have settings that get the most effective use of their air. Anything more than that is just a waste.
Now, look at power setting 6 across all 3 barrels. The velocity increase as the barrel lengthens is smaller with this power setting than with the higher settings. Also, look at the 12-inch barrel between setting 6 and setting zero. That’s where the bulk of the adjustability for this powerplant is when that barrel is installed. But with both the 18-inch and 24-inch barrels, the useful power adjustment range extends all the way up to power setting 10.
Finally, power setting zero had a surprise. The 12-inch barrel was the fastest of the 3. That can be explained by more friction in the other 2 barrels, but it doesn’t explain why the 18-inch barrel was slowest and the 24-inch barrel was faster. That’s one of those anomalies you sometimes see when you test things like this.
I also want to say that the rifle became quieter with the 18-inch barrel, but got noisier again with the 24-inch barrel. You Talon owners don’t have the shrouded barrel the Talon SS owners have, but apparently your barrels are doing a great job of quieting the shots all by themselves.
Of course, all of this was made possible by the use of a chronograph. No amount of listening to how long it takes the pellet to hit the hickory tree from the back door will give you results like these.
A word from Edith
As many of our readers know, this blog was originally started on the Blogger site/software, and they’re listed in the right-hand column as the Historical Archives. Those blog posts are being moved to this site from Blogger so everything’s in one place. As originally planned, the comments to the old blog would have been lost. Due to the diligence of several of our blog readers who gave me links to help pages that showed how comments could be transferred along with the posts, we’re not losing anything!
The transfer process is almost complete, and the old blogs/comments will soon be available on this site. One caveat: Blogger posts didn’t have categories and tags when this blog first started, and we didn’t start using them when that feature was added later. So, in my spare time (imagine hysterical laughter at this point), I’ll be categorizing the old posts and creating tags that will help you find related items quicker than if you had to do an ordinary word search.
by Tom Gaylord, a.k.a. B.B. Pelletier
Today’s report is in response to a comment that came in yesterday from a blog reader named David. He asked me to explain what I meant by the terms, “calling the shot” and “follow-through.” I think we have a number of new shooters who may not know what these two terms mean; and if they don’t, then they certainly aren’t doing them. That makes all the difference in the world when it comes to accuracy. I’ll explain both terms, then I’ll tell you how you can determine that you definitely are neither calling the shot nor following through with a handgun.
Calling the shot
When you align open sights on the target, your focus is supposed to be on the front sight element. The rear sight and the target will both be blurry when you do it right. Novice shooters think this is wrong…how can you hit the target unless you focus on it? But the truth is that this is the only way to be extremely accurate.
When you’re really concentrating on the front sight, you’ll be able to see the alignment of the front and rear sights against the target as the gun fires. This works best when the gun is a lower-powered one — something I want to talk about later.
Let me illustrate the importance of proper sight alignment with the following graphic.
In the top image, the front and rear sights are properly aligned and also aligned correctly with the target. In the center, we see what happens when the front sight is not aligned with the rear sight. The bottom graphic shows what happens when the sights are properly aligned, but they are not aligned with the target.
Which is worse: Not aligning the sights with each other or not aligning the sights with the target? Obviously it’s not aligning the sights with each other, because that throws the impact of the pellet farther off the target than simply not being lined up with the target.
Here’s the proof
Matt61 — this is for you and your father. If your father is right-handed and shooting his pistol one-handed, I guarantee that he is throwing all his 1911 .45 ACP shots low and to the left. How do I know that? Because it’s what everybody does. He’s not squeezing the trigger so it releases unexpectedly. He is pulling it with a quick jerk of his trigger finger; and if you hold a 1911 pistol and do the same thing, you’ll see the muzzle dip low and to the left. If he’s a lefty, the shots are landing low and to the right for the same reason. It works the same for revolvers.
It’s harder to say what will happen with a rifle because there are so many ways to hold a rifle. Also, some of the 2-hand pistol holds can change where the bullets land a bit, but this still holds true more often than not. A shooter with experience can look at the holes in a target and spot this kind of thing immediately.
Not following through
The cause of throwing a shot this way is because the shooter is not following through. They pull the trigger and immediately take their eyes off the sights. Then they start taking their eyes off the sights an instant before they pull the trigger.
Following through means that you continue to hold your aim after the shot has fired. It takes discipline to do it, but it’s the only way that you will ever be able to tell where the sights were when the shot fired. It’s the only way you will ever be able to call where the shot went.
Calling the shot is nothing more than noting the alignment of the front and rear sight at the instant the shot fired and also noting where the sights were in relation to the target. If you follow through, you should be able to do this most of the time — as long as you don’t blink when the shot fires. And, yes, that does happen to even the best shooters.
Impossible shots become possible
Matt61 mentioned yesterday that I’d made some incredibly long shots with a short-barreled handgun. In fact, what I did was hit a football-sized dirt clod repeatedly at 80 yards with a Colt Detective Special snub-nosed revolver that had a 2-inch barrel. You aren’t supposed to be able to do things like that with a snub-nosed revolver, but let me tell you how I did it.
I was sitting on the edge of a plowed field in Germany in the mid-1970s. The field had not been disked yet, so the dirt clods were still large. I sat resting my back against a tree and held the revolver with both hands between my knees for bracing. I asked a friend to tell me where the bullets went. He could see the puffs of dirt when the .38 Special bullets impacted the ground.
The fixed sights on a Detective Special are large and very close together because of the short barrel, so the sight picture was easy to see. But even the slightest misalignment threw the bullet off-course by several feet at 80 yards. It probably took 2 full cylinders before I got the range on that clod; but once I did, all I had to do was align the sights the same every time and put the clod on top of the front blade. After that, I hit the clod repeatedly.
Colt Detective Special is a typical snub-nosed .38 Special revolver. The rear sight is not obvious in this photo. It’s a notch in the top rear of the frame ahead of the hammer.
Elmer Keith wrote about the way to make that shot, and I believed him. I did what he said and it turned out to be true.
This is the sight picture I used on the dirt-clod shot. I’ve enlarged the dirt clod many times for clarity here. It was actually much smaller than the width of the front sight.
You have to follow through to be able to call your shots. And now you know what calling your shots means. It means knowing how the sights were aligned and how they related to the target at the instant the gun fired. Don’t try to do this with a large-caliber gun the first time. A pellet gun is the best to start with because the noise and recoil are minimal. A .22 rimfire is another wonderful way to do this.
Once you get enough skill, you can graduate to progressively larger calibers and calling your shots will become almost second nature. I can call mine with a Desert Eagle .44 Magnum pistol now, when I want to. But it still takes concentration, and I don’t think that will ever change.
by Tom Gaylord, a.k.a. B.B. Pelletier
Today’s report goes out to all those readers who are just getting into airguns, as well as those who have been in airguns awhile but feel there are many things they’re either missing or don’t fully understand.
We have a new blog reader who goes by the name Essbee. For the past week, he’s been asking the kind of specific questions that tell me he doesn’t understand something as well as he would like to. Then yesterday, he sent in this set of questions:
Thanks. How does The Benjamin Marauder compare with German guns (RWS & Weihrauch) in terms of quality and durability and ease too. No doubt the Germans are pricey in PCP hence ruled out but their quality is no problem. Could I have a report for or against on the quality of Benjamin Marauder as compared to German technology and craftsmanship.
What are the chances the gas will leak on PCP guns. If it does how will it be fixed and at what cost? In contrast the air springers have no such problem. What do you say on this? What is the record at your end of PCP repairs vs air springers?
Hence I was comparing an RWS 34, RWS 350 Magnum and RWS Air King 54. Considering the cocking effort, weight and velocity it seems RWS 34 stands up very well in .22 with longer barrel. Am I correct? For hunting which is the best?
How do I answer this?
If you read the questions, you’ll see they’re a combination of technical questions and requests for my subjective opinions. I find it very difficult to answer questions like these because they require more time and space than we have available. So, what I do is try to guess about who’s asking the question, then answer from that standpoint as best I can.
New airgunners come from a variety of backgrounds. They can be youngsters who have never really sampled the shooting sports at all. Everything is a mystery to them. Or they can be adults who may know about the shooting sports but have never really participated in them. You might think that would make them the same as the youngsters, but it doesn’t. Adults do have some life experience to relate to, so they can understand things that youngsters haven’t experienced yet. My answers to adults have to be slightly different than the same answers to youngsters.
The questions can also come from adults with lots of shooting experience but who are just getting into airguns. When that’s the case, we have a common basis of shooting upon which to build, but they still won’t be familiar with things like the artillery hold or with canting issues at close range.
Some of these adults may have served in the armed forces and may be even more familiar with firearms than most people. That makes my answers even more difficult because there are things about airguns that the military never thought of.
Some of the questions come from law enforcement officers, both retired and active duty. They’ll have an even different viewpoint, and my answers will have to be presented differently.
So — how do you get into airguns?
I obviously can’t answer everyone in the same way. But I do think there are fundamental things that ALL new airgunners need to think about. So here we go.
1. Start small
Don’t buy that super-duper ultra-magnum that you see advertised. Forget the advertising hype, unless all you want is something to brag about. If that’s what drives you, go somewhere else because I can’t help you. I’m in this for the enjoyment of the hobby — not for posturing, looking good or counting coup.
Get a weak but accurate airgun as your first gun, and then learn to shoot it. Forget scopes unless you’re almost legally blind. Learn to shoot with open sights. Learn to follow-through on every shot. Learn to call your shots, which is to state where they went before you look through the spotting scope.
I would tell you to get a Diana model 27, but they don’t make them anymore; and many of you would rather purchase a new gun. Okay, get an Air Venturi Bronco. That rifle was created to be the modern equivalent of the Diana 27. Is it? Probably not, because there are too many things that aren’t the same. But the Bronco is accurate, it has a good trigger, it’s both light and easy to cock, and it comes in .177 caliber so the pellets are cheap. And the rifle, itself, is a great bargain.
Want a different choice? Okay, consider a Stoeger X5. For around $90, you get everything the Bronco has except the great trigger and some of the accuracy. But it’s very good and is a wonderful way to break into airgunning. Find something like that.
Want an air pistol? How about a Beeman P17? Oh, you can find bad reports about this pistol if you look, but they number in the dozens, while thousands of pistols have been sold. I have had 2 and both were quite reliable. One was a test gun from Pyramyd Air and I bought the other one after returning the test gun. The one I have now has many shots on the clock, as well as many years on it, and still performs as good as it did when it was new.
Want a spring pistol? Try the Ruger Mark 1 pellet pistol. It’s inexpensive, accurate, easy to cock, and the trigger–while heavy–is manageable.
I said to start small with a low-powered pellet gun and learn how to shoot it. That’s the best advice I can give anyone who wants to get into this hobby. Yes, the powerful guns are neat and the super-accurate guns are a ball to shoot, but they also require some understanding that only comes with practice. I want you to get as much trigger time as possible, and a lightweight, inexpensive, accurate gun is the way to do that.
2. Buy good pellets
I know that saving money is a good thing, but I don’t want you to miss out on the thrill of a lifetime just so you can save a dollar a tin on bargain pellets. Stop kidding yourself that you can buy good pellets at a discount store. That was never the case, and today it’s quite far from the truth. You might be able to buy some adequate pellets at a discount store, but where does that leave you? With a Bronco that shoots 1.5-inch groups at 25 yards instead of one that shoots 3/4-inch groups. Is that what you want? You know the best way to save money is to never shoot at all. If you’re going to shoot, give yourself a chance of hitting.
3. Stop fighting the trends and start applying yourself
A popular definition of a crazy person is one who keeps doing the same things and hopes for different results. I see shooters who aren’t using the artillery hold because they say it’s too hard. Well, of course it’s hard, but all the best shots do it. Don’t you want to see what kind of shot you can be? If you try to buck the trend and avoid things like the artillery hold, you’re acting like a NASCAR wannabe who doesn’t like cars that are set up for the racetrack. Sure they’re hard to drive, but they’re also the only kind of cars that win the races!
You want to shoot groups at 100 yards, but you don’t want to use a scope level. Great. That’s like an ice-skater who wants to be in Hush Puppies all day because the skates hurt his ankles. You can’t shoot tight groups at 100 yards without leveling your rifle for every shot. So, if you don’t use a scope level, you’ll have to find some other way of doing it.
I know it sounds simple, but just shoot. That’s why you decided to get into airgunning in the first place. It’s so easy to shoot at home. I fire from 100 to 1,000 rounds each and every week.
The more you shoot, the more chances you have to improve. Not that all people do improve, mind you, but at least you have the chance.
I’ve found that 20 shots on your own is worth a lot more than 20 conversations about shooting on the internet. Go on and have the conversations — but do the shooting, too.
This is what I would tell a new airgunner. Too often — always, in fact — they come to me with their eyes sparkling with thoughts of buying this or that mega-magnum rifle, I know they’re heading for disaster. I cringe when I see this because I know the conversations we’re going to have much later when all they’ve done finally sinks in and they realize this wasn’t the way to go.
Here’s a little story to illustrate what I’ve been saying. I watch certain internet gun sales websites and from time to time certain guns are listed. Let’s single out the Smith & Wesson 500 Magnum for this story. When I see the ad, I can guess what it will say. This fine gun is almost new in the box. It’s only been fired a few times. Comes with a fresh box of ammunition and only 6 cartridges have been fired. Now, why do you suppose that is?
by Tom Gaylord, a.k.a. B.B. Pelletier
Today’s blog is a result of several blog reader comments about the BSA Scorpion 1200 SE PCP air rifle I started reviewing for you several days ago. Reader Lee asked if there was any advantage to the higher fill pressure, and J-F followed up with a couple comments of his own. I find this to be an excellent question since it touches the core of precharged pneumatic operations. I thought I’d start a discussion of the impact that fill pressure has on precharged operations.
The modern precharged pneumatic air rifle was built by Daystate in 1980. It was a .22-caliber rifle called the Huntsman that was roughly based on a dart gun Daystate was making for game management. When I got into precharged guns in 1995, I bought a used Huntsman Mk II and was surprised that the maximum fill pressure was only about 2,500 psi. I discovered that by shooting the rifle over the chronograph, which in the olden days was the only way to do it. Nobody published any data on the number of shots a gun got, and this blog was still a decade in the future. At that pressure, I got 30 good shots at 12 foot-pounds. But that raises a good question. What do I mean by a good shot?
What is a good shot?
This is a huge precharged topic and a grand area of misunderstanding. What is meant by a good shot? When I say it, I mean a shot that falls within a tight band of consistent velocity that will enable me to shoot great groups at 50 yards. Regular readers of this blog know what I mean by great groups, but for the newer readers I would define a great group at 10 shots inside a group that measures 0.75 inches between the centers of the 2 shots farthest apart. To me, that would be great at 50 yards.
But when many shooters talk about good shots, they mean that the pellet still comes out the end of the barrel. They’re standing in their backyards. They don’t own a chronograph. To them a good shot is when they pull the trigger and something comes out the end that has the little hole in it. If it also happens to hit the tin can they’re shooting at, it’s a great shot. Yes, people do think this way — even the owners of $1,500 super-dooper PCPs. In fact, there’s good evidence that more people think like this than those who agree with my definition.
So, the more universally accepted definition of a good shot is one that launches a pellet from the airgun. That being the case, there’s a big misunderstanding when it comes to the number of good shots a particular airgun may have. Manufacturers have trended toward publishing the number of shots that will result in the way most shooters define them, while I have always published the number of shots that fall within a tight velocity band. Both numbers are correct, but they don’t tell the same story. I’m going to be sensitive to this difference in the future, and I’ll probably expand my velocity testing of PCPs to accommodate the two definitions when I feel it’s necessary.
Back to the title question
So, what does higher fill pressure give you? Do you get more shots on a fill? Well, which definition are you using? If you use my narrow-velocity-band definition, then the answer is probably no. All a higher fill pressure does is move the starting and ending air pressure levels higher. You may have to fill to 3,365 psi and shoot until the velocity variation exceeds 30 f.p.s., which leaves you with 2,600 psi remaining in the reservoir.
But if you use the broader definition that as long as the pellet comes out of the muzzle the shot is good, then a higher fill pressure will give more shots. You can probably keep right on shooting until there’s only 800 psi remaining in the reservoir, and the shot count will more than double. Of course, the velocity may vary by over 700 f.p.s. from start to finish; but to the guy rolling cans in his backyard, that makes no difference. He begins to sense his gun needs a fill when he starts seeing the pellets in flight and notices how they arc slowly toward the target. I sense a need to refill when my 50-yard, 10-shot, three-quarter-inch groups expand to more than an inch!
Okay — let’s say you understand that there’s a large difference between my definition of what constitutes a good shot and the more generally accepted definition. What should you do about it?
To answer that, you have to ask yourself what it is you want to do with an airgun. Do you want to pursue the ultimate in precision? If so, you probably want to use some variation of my definition of what makes a good shot. The reason for variation is you may not shoot at 50 yards. You may shoot only at 35 yards. If that’s the case, you can accept a wider velocity variation than I. That will give you a few more shots per fill than I get.
Or are you trying to shoot good groups at 100 yards? In that case, you’re probably going to be more critical than I am about velocity variation. You’ll get even fewer shots per fill than I do.
But if you’re just out for a good time with your airgun and your targets are big enough to provide some leeway on where they’re hit, you could care less about the velocity spread. You just want to fill your gun and start shooting. You don’t stop until you can no longer hit what you’re aiming at.
Two categories of precharged valves
Given the discussion above, I see precharged valves falling into 2 categories. The first category is a valve that holds back the air until it’s knocked open. When that happens, it lets the air out as long as it remains open. We call this a knock-open valve. A valve like this gives its most powerful shot as the first shot, then the velocity starts to drop in nearly a straight line. Start to finish, the velocity is always dropping as the shot count increases.
Many of the Korean precharged guns have this type of valve. I remember the old Career 707 lever-action rifles would drop velocity in a straight line from the first shot to the last.
The other category of valve is one that’s balanced to operate within a certain pressure range. By balanced, I mean the following. The weight of the valve return spring is adjusted to compliment the weight of the striker, the power of the striker spring and the length of the striker stroke. The size of the valve seat, which determines the size of the air passage out of the valve, is adjusted to compliment the return spring strength, striker spring strength, striker weight and the length of the striker stroke. You could call a valve like this a “balanced valve” since all these considerations have been balanced against each other. It operates the same way that a straight knock-open valve does, but in this case a lot of attention has been given to the individual firing components. There’s no formal definition for a balanced valve, but these are the considerations that are taken into account when that label is used.
When Crosman developed the Benjamin Discovery PCP air rifle in 2006, they had to carefully balance the valve to work at a fill pressure of 2,000 psi. They were working in unfamiliar territory; because at that time, 3,000 psi was a nearly universal PCP fill pressure. I’d given them a presentation of a PCP rifle that would operate on a lower fill pressure, and I used the USFT rifle made by Mac-1 Airguns as an example of what could be done. That rifle used 1,650 psi to get 55 good shots by my narrow-velocity definition. It did so because it has a huge air reservoir.
The Mac-1 USFT rifle uses low-pressure compressed air but gets a lot of shots that are very close to each other in velocity. It has a delicately balanced valve that uses the air from a very large reservoir.
As a second example, I also told Crosman about a .25-caliber air rifle made for me by Gary Barnes. That rifle operated on a fill pressure of just 600 psi, yet it got 10 shots that developed as much as 27 foot-pounds of energy. That rifle did what it did because it had a valve that remained open for a very long time, and it also had a barrel that was 32-3/4 inches long, which gave the compressed air a long time to push the pellet.
Gary Barnes made this outside lock air rifle in .25 caliber. It was a copy of an 18th century airgun lock whose parts were attached to the outside of the lock.
Gary Barnes made the rifle with the outside lock (shown at the top). The bottom lock is a genuine lock from the early 1700s that Barnes used as a model. The way the lock works, it holds the air valve open much longer than a traditional impact valve.
Crosman was amazed to discover that the lower air pressure idea really worked. In just 3 days, they built prototype .177- and .22-caliber rifles from their 2260 CO2 rifle. Once they had the concept down, they fully developed the idea into the rifle that we know today as the Discovery. To keep the retail price as low as possible, that rifle was hardwired with all the lessons they’d learned about air valves.
But one year later, they came out with the Benjamin Marauder, which allowed the owner to adjust the air flow, the striker spring tension and the striker stroke length. This put the capability to tune the gun into the user’s hands. And this report has given you the information you need to understand how it all works.
I will continue to test PCPs like the BSA Scorpion 1200 SE in the way that I always have, and I’ll keep telling you what kind of velocity spread I’m accepting for the shots I call good. But I’ll also shoot these rifles a lot longer, recording the velocities as I go. I’ll give you the data that most backyard shooters never have, nor seem to want. From that, we’ll get a much larger number of usable shots from a fill. And, to paraphrase the Fox News tagline, “I’ll report. You decide.”
by Tom Gaylord, a.k.a. B.B. Pelletier
Today’s report is a guest blog from reader Fred from the Democratik People’s Republik of New Jersey. It came from his ingenuity in dealing with a need that arose in the field. I’ve linked it to the recent .177 Marauder reports because it seems to fit.
If you’d like to write a guest post for this blog, please email us.
Over to you, Fred.
Fixing a Marauder magazine
by Fred DPRONJ
A number of factors led to this blog — the first being a scheduled benchrest .22 rifle competition my league was going to hold following our 25-yard bullseye competition. The second was, I believe, blog reader John. Or was it Mike? No matter. But whoever made the comment mentioned later in my report…thank you!
I had gone to the range several days ahead of the benchrest competition to sight in my .22 cal. Benjamin Marauder. For fun, I decided to take on the rimfire boys with my air rifle. It took roughly 6 pellets to get the scope sighted where I wanted. However, I could not see where pellet 7 landed. Two more shots and I was incredulous. The rifle had gone from hitting the 10 ring to missing the entire target paper and backer. At this point, I looked at the magazine and discovered it was not rotating to feed the next pellet. It was stuck after firing pellet 6. I assumed the internal spring had broken, so I packed up and went home discouraged. I didn’t have another .22-caliber Marauder magazine, so I might have to use my Ruger 10/22 for the competition.
However, I recalled John (?) mentioning in the blog comments that these magazines could come apart. At home, I carefully examined the magazine under magnifying glasses and saw that what I had believed to be a rivet in the center of the magazine was actually an Allen screw.
A 1.5mm Allen wrench fit; after initial resistance, the screw was removed.
The magazine is really an elegant engineering solution for the task of feeding pellets with a bolt action. It consists of 5 parts — an outer case, a coiled spring, the circular pellet holder, the clear plastic cover and the the screw that holds everything together. When I disassembled it, nothing appeared broken.
If you look very carefully at the coiled spring, you will note that the ends are different. While both ends are bent at 90 degrees, one is bent away from the coils while the other end is bent down to stick into a hole in the bottom of the magazine case.
One end of the spring is bent out at a 90-degree angle, while the other end (not visible here) is straight in line with the coils. This is the end that sticks into one of the holes in the bottom of the magazine case.
The end that you see in the above picture goes into one of three holes in the magazine case. Each hole gives a different amount of pre-load to the spring.
I decided to insert the spring into the hole nearest the bottom of the case, next to the cutout that slides over the breech when the magazine is installed. In the above photo, that hole appears at the 9 o’clock position, and you can see the cutout that goes around the breech very clearly.
Here’s the magazine spring. Now you can see both ends. The end on the left goes into one of those holes in the bottom of the magazine case, and the end that sticks out on the right fits into the slot on the underside of the pellet holder.
The straight end of the spring that sticks out, away from the spring coils, goes into the slot in the underside of the pellet holder. It’s just a matter of approximating position of the holder’s slot to the spring and moving it back and forth until the spring end clicks in. You easily feel when it pops into the slot.
The pellet holder has a circular groove in it, and the brass pin of the cover moves in it. The groove is almost a complete circle, but the part that isn’t grooved allows the cover to rotate the pellet holder against the coiled spring when the magazine is loaded.
The magazine case with the spring and the pellet holder in place. Notice the circular groove in the pellet holder, next to the numbers. This is where the brass pin of the cover fits, allowing the pellet holder to move as the pellets are pushed out of the magazine by the bolt.
With the pellet holder in position, I pressed it down and slid the clear plastic cover over it and then aligned the cover with the magazine case and inserted the Allen screw. [B.B.'s note: The brass pin in the bottom of the clear plastic cover has to be inside the circular groove of the pellet holder, and the pellet holder stop (the portion of the pellet holder that protrudes) must be to the right of the shelf inside the magazine's outer case.]
I slide the clear plastic cover over the pellet wheel to keep it in constant contact with the coil spring so the end of the spring would not come out from the notch on the underside of the pellet holder.
The secret of my feeding problem was now revealed. The screw that holds the cover should be tightened only enough to remove any excess slop between the clear plastic cover and the magazine case. Too much tightening and the cover binds the pellet holder, preventing it from turning. The screw has an interference fit so it won’t back out when you rotate the clear plastic cover to load. Lifting and rotating the cover 90 degrees and releasing, the cover now snapped back with authority — indicating the assembly screw was tight enough and the magazine spring was doing its job. I was now set for my benchrest competition.
If this procedure seems confusing, believe me — it clears up when you have the 5 parts of the magazine in your hand. I have given you all of the references you will need to assemble your own magazines, should you attempt this yourself.
[B.B.'s note: I disassembled and assembled my Marauder magazine several times following these instructions. They do work.]
by Tom Gaylord, a.k.a. B.B. Pelletier
Do you ever have preconceptions that are totally destroyed when you see what you thought you knew? That’s what happened to me with the BSA Scorpion 1200 SE PCP air rifle. Pyramyd Air shipped this rifle to me especially for this review because they want to get the word out as quickly as possible. So, here we go.
I was expecting something completely different. Something more like the BSA Hornet of several years ago. I’ve tested 2 different versions of that rifle already and was calling up the memories when the box popped open, revealing something completely different.
This model is a repeater. It has a 10-shot magazine and an exposed bolt. The magazine sticks out the left side of the action, so sidewheel scopes with large wheels won’t work because the wheel will block access to the magazine. To remove the mag, you must first cock the bolt and second push a locking pin forward on the left side of the action. Then, the mag comes straight out the left side of the gun.
The barrel has a large jacket that ends in a threaded cap. Remove the cap to expose UK-spec 1/2-inch by 20 UNF threads for a silencer. I looked inside the jacket and cannot see any baffles or chambers, so I’m thinking this rifle is going to be loud. I do own a legal firearm silencer, but it’s set up with American standard 1/2-inch by 28 UNF threads that will not attach to this airgun. No doubt, an adapter could be made, but since most shooters don’t own a legal silencer, there’s probably no reason to make one.
The rifle came with a single piece of paper containing the operating instructions, and a CD with a bunch of videos…and they’re not necessarily specific to this gun (I saw one about the BSA Hornet). Also on the CD was a file named Start.exe. What a shame they didn’t make a PDF file so I could open it on my Mac. It can only be opened by Windows users. Not everyone owns a computer; of those who do, not all of them are Windows platforms. That left me with the paper pamphlet, which does contain the minimum information I needed. Edith will get Pyramyd Air to send her the Start doc in format we can use, and they will keep it in the online library if it pertains to the gun.
This model comes in both .177 and .22 calibers, and there are 2 different power levels. A 12 foot-pound model exists, but they aren’t being imported. The rifle I’m testing is the .22-caliber FAC (a UK designation for Firearm Certificate — required in the UK for an air rifle that generates more than 12 foot-pounds of energy at the muzzle) version. Marked on the the end flap of the carton this rifle came in is the velocity of 1,200 f.p.s., so it should be a screamer! Naturally, we’ll test that with several different pellets. The serial number of the rifle I’m testing is TH220104-13.
The manual says I can expect 25 shots per 232 bar fill. That’s 3,365 psi, so I’m either going to fill with a carbon fiber tank or with a Hill hand pump because nothing else goes that high. Because the rifle comes with yet another and different proprietary quick-fill probe, the Hill pump will get drafted. I need to reserve my carbon fiber tank for filling all my PCPs that have the now nearly universal Foster quick-disconnect fill couplings.
Proprietary BSA fill probe (bottom) comes with 2 replacement o-rings, plus an Allen wrench for the gun (trigger) another o-ring (for the bolt?) and a small tube of moly grease for the o-rings on the filler probe.
The rifle is just over 44-1/2 inches long and weighs 8 lbs., 12 oz., unloaded with no scope mounted. The balance is decidedly muzzle-heavy, as the 24-inch barrel really sticks out far. The stock is black synthetic and seems quite solid. It has a rough finish that helps with your grip. And as can be seen in the photo, the shape is ultra-modern. A raised cheekpiece rolls over on both sides of the butt and gives a Monte Carlo profile. The butt ends in a thick black rubber recoil pad, and the pistol grip is both vertical with a palm swell on both sides, making the rifle as ambidextrous as possible, save the location of the bolt handle (right side) and the safety (left side).
There are no sights, so some kind of optical sight will have to be mounted. You need to know that BSA has a good reputation when it comes to air rifle barrels. Their association with Gamo hasn’t changed that one iota. Their barrels have long been used by other makers of precharged rifles because of the sterling reputation. So, when I say it will need an optical sight, I’m planning on mounting a fine scope, for I feel certain this rifle will do well out to 50 yards, at least.
Receiver is flat on top. Magazine fits below the top of the receiver, making low scope mounting a possibility. The square button on the left at the rear of the barrel is pushed forward to release the magazine.
The trigger is 2-stage and adjustable for the length and weight of the second-stage pull. The sear appears to be direct contact, so care must be exercised when adjusting the trigger to ensure there’s enough sear contact to hold the striker safely. I’ll look at trigger adjustments in Part 2.
This is a BSA PCP, so I anticipate accuracy. The balance is very good, and this feels like a hunter’s rifle. Given the advertised power, that’s exactly what it should be. If the trigger bears out in testing, the BSA Scorpion 1200 SE will be another fine PCP for your consideration.