Posts Tagged ‘multi-stroke pneumatic’

Oops! My Benjamin 397 has valve lock!

by B.B. Pelletier


The Benjamin 397 (left) is a powerful multi-pump. Obsolete 397 carbine at right.

Today, we have a critical report about airgun maintenance and operation. So, if we’re being critical, let’s start with the title. It’s a It’s no one’s fault — let’s all get along title. It should read, Oops! I really screwed up! And when I say “I,” that’s exactly what I mean!

About a month ago, a friend of mine — who shall remain nameless, unless he repeates what I am about to tell you — received a new Benjamin 397 multi-pump pneumatic. Hurray!

I went over all the operational and maintenance steps carefully with him — pump it no more than 10 times per shot, always store it with one pump in it, use Pellgunoil on the pump head etc. — and then turned him loose with his new rifle. Last week the rifle came back to me with the complaint that it didn’t fire pellets anymore.

I must have looked like that old plumber who knows just where to tap the pipe to get the system going again, because before I even examined the rifle I told him it was over-pumped and therefore valve-locked. Then, I took the rifle and opened the pump handle, which sprang open with a lot of force. Yep — it’s valve-locked, all right!

I listened carefully to the story of how it couldn’t possibly have been anything that he did wrong. I’ve heard that same story a hundred times before; but like a compassionate priest, you have to let them confess everything as you listen in silence. On about the third go-round, I got the real story.

It seems he was at work, shooting his new gun with a buddy who was also shooting his own multi-pump. Remember, folks, we’re talking Texas, here. Depending on your job, shooting at work isn’t that uncommon. Perhaps not at a funeral home or at a fast-food franchise, but there are a lot of outdoor jobs where shooting is possible and not objectionable.

They were shooting at a metal sign that the buddy’s gun wasn’t able to dent very much, but the 397 put a big ole’ dent in it. However, something wasn’t right! It seems the other guy’s pump gun was much easier to pump than the 397. What was wrong with the 397?

What was wrong with it was that it wasn’t a Crosman 760, like the other guy’s gun! At least that’s my guess. I’m still waiting to hear what the other guy’s gun was.

So, his new gun was harder to pump, but it was also a lot more powerful. MAYBE he wanted to see if the 397 would go all the way through the sign, thus vexing his friend, which is the tradition whenever two guys shoot together. He pumped it ALL the way up, being VERY CAREFUL not to exceed the 10-pump limit, as I’d instructed him. But that time it fired only weakly.

He handed his rifle to his friend, who then pumped it up again, also being VERY CAREFUL not to exceed the 10-pump limit, because the owner was watching him. This time when the trigger was pulled, the gun just went CLICK and no pellet came out. So, now he knows that his gun doesn’t work anymore.

At least he stopped when it got to this point. He didn’t keep loading pellets and pumping it a couple more times just to be sure. I have seen owners do that before.

He brought me the rifle and asked if I could possibly help him. I told him there are two ways to go about this. One is to wait a couple months and hope that the gun leaks down enough that the valve is no longer locked. If the gun had not been properly oiled with Crosman Pellgunoil, that might have been a possible solution. But it was well-oiled, and I didn’t think it would leak down in even a year!

I decided to go the other way. I would remove the extra air mechanically by partially disassembling the gun and rapping on the valve stem with a heavier hammer. That’s how the repair center fixes guns that are over-pumped. Or, at least it used to be! This is where the “old plumber” became a student, again.

I discovered that the new 397′s design is vastly different from what I was used to. You can no longer do what I just said because the gun is not designed to allow it. The new design is much cheaper to build and easier to repair — except when the gun is over-pumped. I’ll describe what I did and what happened as a result — and I don’t see any other way of doing the job.

Poor photos today
I apologize for the poor photos that follow. I was working on the gun and getting dirty, so I used the flash on the camera to make the work go faster. That’s why everything is so over-exposed.


What appears to be the stock screw also holds the valve inside the pressure tube. If the rifle is pressurized, this screw will be under pressure from the valve body trying to move! If this is the case, remove the bolt before you loosen this screw!

The new 397 valve is held in the gun by the single stock screw. That screw fastens the trigger group to the action, and there’s no way to rap out the air the way I described it earlier. I did an internet search and discovered there were no instructions on what to do! In fact, everyone dances around this design almost as though they don’t understand it, though I’m quite sure most of them do. It’s so much simpler than the guns I’m used to. When a gun is over-pumped, there seems to be no good way of depressurizing it — other than to remove the single screw I just described and let the air blow out. But before you do, be sure to remove the bolt first!


Remove the two sideplate screws and the sideplate and cocking plate will come off (right and left, respectively in this photo). Then, you can remove the Allen screw from the bolt.


Once the Allen screw is out, the bolt slides out of the receiver.

I didn’t know it while I was doing it, of course, but when the stock screw backed out sufficiently far, the air exploded out of the gun as the valve moved within the pressure tube. It caught me by surprise, but in retrospect I can’t see a better way of doing the job. If anyone knows of one, I’d like to hear what it is.

In retrospect, I should have removed the bolt from the gun before removing the stock bolt. To do that, remove the two screws that hold the sideplate to the left side of the action, exposing the Allen screw on the bolt that cocks the hammer. Then remove the Allen screw, and the bolt slides out of the action.


The action can be removed from the stock when the one Phillips screw is loose. The screw is captive inside the stock and doesn’t show here.

At this point, I finished the disassembly, checked all the parts to see that they were okay, which they were, and assembled the gun again. There’s a trick to assembling this gun. The pump arm must be swung forward to allow the valve to go forward enough for access to the screw hole. If you do that, this is an easy pneumatic to assemble. If you don’t — good luck!


You’re looking through the screw slot in the triggerguard at the brass valve body and its fastening screw hole. How many people would realize that their one stock screw is holding all this?


This picture shows why you cannot just rap out the air anymore. The rear of the pressure tube is blocked by the back of the trigger assembly, which has to be removed to gain access to the valve.

And how does it work?
The rifle now works fine, but I’ll run a little test to see how fine. I’ll shoot the gun through a chronograph on six pumps, and keep increasing the number of pumps until there air remains in the gun after the shot. Then, I can tell the owner what the exact maximum safe number of pumps are for this specific gun. That’s another great reason for owning a chronograph!

Checking the velocity
I decided to use Crosman Premiers in the 7.9-grain weight for my test pellets. This is what the gun now does.

Pumps…Velocity…Air remaining?
6………….613………..No
7………….650………..No
8………….688………..Yes! A soft pop was heard.
9………….713………..Yes — a second shot went 555 f.p.s.

Chronograph reveals what happened
It’s easy to see what happened to this rifle. I told the guy that 10 pumps was the maximum, because I thought that was what the owner’s manual said. But it isn’t! Crosman has folded the Benjamin rifles and Sheridan rifles together, and now they all top out at 8 pumps. So, I was responsible for the owner over-pumping his gun! Several years ago, when the Benjamin and Sheridan brands were different, the Sheridan stopped at 8 pumps but the Benjamins stopped at 10. But those days are over. Now they all stop at 8. So — shame on me! Apparently this is my week for confessing my sins.

What if you don’t own a chronograph?
But you don’t care about that! You care about your own air rifle, and, since you don’t own a chronograph yet, how can you determine the exact number of pumps that are maximum for your rifle? It’s simple. Do what I did above and increase each shot by one pump. Then cock the rifle afterward and fire it again without a pellet. Listen for the pop of escaping air. When you hear it, back off one pump and that is the maximum number of pumps your rifle can handle.

Just to be safe, pump your rifle to the newly established maximum number of shots five times and shoot it. After the fifth shot, cock the gun once more without pumping it and fire it again, listening for a pop. Sometimes the amount of air that remains is so low you cannot hear it, but after a cumulative five shots, you should be able to hear it very well.

Lessons learned
I got the tables turned on me this time. And I also learned how easy it is to work on these new Benjamin rifles. And you readers got to watch everything over my shoulder, plus you got a new way of testing the maximum number of pumps for your specific pump rifles if you don’t own a chronograph. I would call that a good day’s work!

Crosman 2100B multi-pump air rifle: Part 3

by B.B. Pelletier

Part 1
Part 2


Crosman’s 2100B is a full-sized multi-pump that hopefully delivers power and accuracy with a few economic concessions.

Blog reader J was alert and noticed that I had not yet done the accuracy test of the Crosman 2100B multi-pump. I was astonished to find that he was right, so today we’re going to look at it. But before we do, I want to show you something I did at the range last week. Some of you who have been reading for a long time will remember that over a year ago I was suffering from eye problems. It turns out that my diabetes had dehydrated me so much that my eyesight was affected. And it took a long time for the situation to correct itself. I wondered if I would ever be able to shoot with open sights again.

This past Thursday, I was out at the range testing several firearms and airguns and a friend of mine happened to bring his Remington RangeMaster model 37 .22 rimfire target rifle for me to try. The model 37 was Remington’s equivalent to Winchester’s model 52 target rifle until the model 40X was created, and it (the model 37) has the reputation of being incredibly accurate. My friend can no longer use open sights and is scoping all the rifles he intends to keep. But this one is a rifle he has owned for decades but never shot. It still has the factory non-optical target sights.

The Lyman 17A front globe has a post-and-bead like target shooters used back in the 1930s and earlier. You put the post at the 6 o’clock spot on the bull. With good eyes, this kind of sight is considered second only to a properly sized aperture front sight out to 200 yards, and world records have been set with it. But notice I said, “With good eyes.”

I shot it at 50 yards with Winchester Super-X high-speed ammo, which is hardly target ammo! When I saw the group made with five shots I was ecstatic, because it proves that I can still see good enough to use open sights. I stopped at only five shots because who wants to ruin a group like that? However, after an involved trade with my friend, I ensured many more years of shooting this 37, and eventually I will shoot 10-shot groups.  That’s important for today’s report, because the Crosman 2100B has a square post-and-notch sight, and the front has a bright green fiberoptic bead.


Five shots in 0.30 inches at 50 yards with open sights! The old man can still see! Sorry about the over-exposure.

Next, I tried my custom .17 HM2 that this same friend made for me on a Mossberg 44 US action. This rifle has a Leapers scope, so there’s an even better chance of hitting the target. This time, five shots went into 0.266 inches at the same 50 yards. I was on fire! Unfortunately, I haven’t yet mounted the scope on the FWB 300S, so I didn’t have that to test, but everything I shot that day went where I wanted. Since I couldn’t see the group through my scope, I knew it was a small one. And, once again, I chickened out after 5 shots. If I were reporting on the guns and shooting for the record, I would have shot 10 shots with each gun.


Five shots in 0.266 inches at 50 yards with a scope. Not that much better than open sights. It looks better because the .17-caliber bullet is smaller, but the actual size of the group isn’t that much less than the first group.

On to today’s test
I decided to begin shooting pellets with the 2100 at 10 meters. That way, if the rifle proved somewhat inaccurate, I could still keep them inside the trap. The 2100 has a .177 rifled barrel, so pellets should be more accurate than the steel BBs it also shoots. Since this is a Crosman rifle, what better to begin than with 7.9-grain Crosman Premier 7.9-grain domes?

The first thing I did was oil the pump head with several drops of Crosman Pellgunoil. I did that for the velocity test, as well; but since it’s impossible to overdo this step and it does ensure the best compression, I did it again.

I decided on 5 pumps for this test because the velocity test showed that was enough to get all pellets into the 500 f.p.s. range. At 10 meters, that’s all you need for good results. So, this test was very easy on me.

A new way of loading
Many owners may already have discovered what I am about to share; but while I was shooting the Premiers, I discovered a foolproof way of loading them. The loading port on the side of the rifle is too small for most adult fingers, and until now I’ve found it difficult to load the pellet so the head points forward. But during this test, I accidentally discovered that I could drop in a pellet in any attitude and simply elevate the muzzle of the rifle with the receiver rotated to the left so the loading port is angled up. The pellet would then try to right itself at the bottom of the loading channel; and, if it wasn’t aligned, all I had to do was push it forward slightly with the cocking handle and then pull the handle back and the pellet would align itself every time. I tried this with the JSB Exact RS pellets, as well, but they got stuck and didn’t align as easily as the Premier lites. I can’t wait to try this method on my old Crosman 2200.

Sights are okay, but not great
I found the sights easy to acquire and very sharp and crisp, but the method of adjustment leaves a lot to chance. I never did get the group shooting where I wanted it. Also, though I elevated the rear sight nearly all the way, it was still just hitting at the point of aim at 10 meters. Forget about shooting longer distances unless you learn how to hold the front post above the top of the rear notch. But the sights are not important, because this will not be the last test of this rifle. Just like the M4-177 rifle I tested last year, I found the 2100B was far more accurate than the price indicated! In a word, it was phenomenal — which is why I told you about the state of my eyes in the beginning of the report.


Ten Crosman Premier lites went into this 10-meter group that measures 0.539 inches. This is fantastic accuracy for an inexpensive multi-pump with fiberoptic sights.

Next, I tried the JSB Exact RS pellet. I was expecting to see a similar group, which is why what I got surprised me so much.


Ten JSB Exact RS pellets made this huge 10-meter group that measures 1.05 inches. This is obviously not the pellet for this 2100!

What a difference! Crosman could use this as an ad testimonial for Premiers, if they wanted. We all know that the JSB Exact RS is a premium pellet; but in this rifle, the Premier lite is the clear and obvious choice. I already demonstrated that my eyes are up to the task, so there’s nothing to blame in this case but the pellet.

BBs next
After testing two pellet brands, I switched to Crosman Copperhead BBs and fired 10 from a standing supported position at 22 feet. If the group was small, I would then try other brands of BBs, but as you will see that wasn’t necessary.


Ten Crosman Copperhead BBs went into this 2.219-inch group at 22 feet. This demonstrated that it wasn’t worth pursuing BBs any further. My photo inadvertently cropped off a BB hole on the right of the group. It’s on the 5-ring, as it ends on the right margin.

The results
This rifle is deadly accurate with Crosman Premiers and not very good with BBs. I wouldn’t even bother with BBs in the 2100 anymore because I have a host of BB pistols that will out-shoot it. But with Premier lives, it’s a different story.

The 2100B has earned the right to a special 25-yard test with a scope sight. That will come in Part 4, and I charge blog reader J with making sure I don’t forget to do it!

Crosman 2100B multi-pump air rifle: Part 2

by B.B. Pelletier

Part 1


Crosman’s 2100B is a full-sized, multi-pump that hopefully delivers power and accuracy with a few economic concessions.

Today, we’ll look at the velocity of the Crosman 2100B multi-pump, and a strange thing occurred during the test. Actually it was two strange things — one an amazing coincidence and the other just weird. Both relate to oiling the gun, and both will be informative.

First, the coincidence. As I was writing this blog (last week, because I’m in Las Vegas at the SHOT Show this week), I got a question from a reader whose 2100 wasn’t pumping air. I asked him if he had oiled the pump piston head like he was supposed to, and I directed him to the online owner’s manual that tells how to do it and to a blog I wrote years ago that tells the same thing. A couple hours later, I get a thank you message that he’s oiled the gun and it seems to be holding air.

So, there I am in my office pumping the gun and shooting it for velocity and I ask myself about the state of the pump piston head of the particular gun I’m testing. Sure, it’s brand-new, but that doesn’t mean that it has enough oil. I look, and the pump head appears to be dry. For those who wonder what I’m talking about, please read the manual.

Then, I recalled that someone had guessed that this rifle would shoot in the low 600s with lead pellets, because someone he knew had tested it. Lo and behold, it was shooting only about 622 f.p.s. on 10 pumps (which is the maximum) with Crosman Premier 7.9-grain pellets. Wow! He was right!

But, wait! The pump head was dry, so I oiled it with some Gamo oil for CO2 guns. The velocity jumped to 658 f.p.s. with the same pellets and 10 pumps. But after about 10 shots the velocity started declining again.

So, I oiled the pump head again — this time with Crosman Pellgunoil. The velocity jumped to 690 f.p.s. before sliding backward to the 620s.

What did I learn?
First, I re-learned for the umpteenth time how important it is to oil a multi-pump gun. That was all it took to fix the reader’s rifle! Second, I saw that the test 2100 rifle responds to oiling immediately, but falls off again almost as fast.

So, the published velocity of 725 f.p.s. can probably be achieved with real-world lead pellets for a brief time, but this test gun won’t hold that velocity very long. Maybe the material the pump head is made of needs a break-in period? I don’t know. What I do know is that I can change the velocity of this gun by 70 f.p.s. simply by oiling it.

It doesn’t end there, however. While that story was unfolding I was also experimenting with the speed of my pump strokes. Since the pump head seemed somewhat hard, I figured that faster pump strokes would build more pressure. And they did! I could increase the velocity by 10 f.p.s. at least, just by changing the speed at which I pumped. I’ve tried the same thing in the past with other multi-pumps, but this one is particularly sensitive.

I think the most representative method of testing this rifle for velocity is to let it sink back to its lowest velocity and stabilize there. That way, the velocity test will also represent the velocity at which the accuracy test is conducted, because I’m certainly not going to oil the pump head after each and every group! Undoubtedly, there’s sufficient oil in the gun right now because of the two oilings I mentioned.

Crosman Premiers
The first pellet tested was the 7.9-grain Crosman Premier. Since the 2100 is a multi-pump, I decided to test each pellet and BB at 5 pumps and 10. That gives us a good picture of what the gun can do across the entire range.

On 5 pumps, Premier lites averaged 540 f.p.s. when the gun was pumped fast. They ranged from 537 to 543; and at that velocity, they produced 5.12 foot-pounds On 10 pumps, again with rapid pump strokes, this pellet averaged 630 f.p.s. The range went from 628 to 635 f.p.s., and the average muzzle velocity was 6.96 foot-pounds.

JSB Exact 8.4-grain dome
Next I tried the 8.4-grain JSB Exact dome. On 5 fast pumps they averaged 526 f.p.s., with a spread from 517 to 531 f.p.s. The muzzle energy averaged 5.16 foot-pounds. On 10 pumps, they averaged 608 f.p.s. with a spread from 595 to 611 f.p.s. The average muzzle energy was 6.9 foot-pounds.

JSB Exact RS
For a light pellet, I tested the JSB Exact RS. The name of this pellet includes the word Match, but they’re domes, not wadcutters, and cannot be used in formal match shooting. At 7.33 grains, they’re very light, yet I’ve had some good luck with them in other pellet rifles.

In the 2100, 5 pumps gave an average 559 f.p.s. The spread went from 555 to 563 f.p.s. The average energy was 5.09 foot-pounds. On 10 pumps, the average velocity was 646 f.p.s., and the range went from 635 to 654 f.p.s. At the average velocity, the muzzle energy was 6.79 foot-pounds.

So, the reader who said the 2100 wouldn’t get to 700 f.p.s. was right. As long as you don’t shoot it immediately after oiling with Pellgnoil, it won’t shoot that fast. But oil it, and it’ll probably top 700 f.p.s. with lighter pellets.

On to BBs
BBs were next, and with them things are much more standard. Though there are subtle differences in BB brands, they don’t vary as much as pellets. We’ll now see if the advertised velocity of 755 f.p.s is reasonable. Since this is a Crosman gun, I tested it with Crosman Copperhead BBs.

BBs are loaded into the large reservoir, then the gun is shaken and they fall into the smaller spring-loaded magazine. Once the magazine is empty, you can shoot pellets again, even though there BBs are still in the big reservoir; if they aren’t in the magazine, they won’t load automatically.

On 5 pumps, Copperheads averaged 570 f.p.s. They ranged from 564 to 578 f.p.s. At the average velocity, they generated 3.68 foot-pounds of energy at the muzzle. On 10 pumps, they averaged 678 f.p.s. and ranged from 672 to 682 f.p.s. That’s an average muzzle energy of 5.21 foot-pounds.

So the bottom line is that the test gun doesn’t meet its advertised spec for velocity. It falls at least 73 f.p.s. short. It does the same with lead pellets, so I’m withdrawing my remark that the gun is suitable for light hunting. Clearly, it’s below the safe margin. Yes, it will kill small animals, but I could not recommend it for that task based on these results.

I also note that the barrel is starting to loosen at the breech. It rotates slightly at this point, and I’ll keep an eye on it. And the pump lever hits the gun with a loud slap on every pump stroke — there’s no cushioning material to deaden the sound.

I hope these results don’t disturb owners of this gun, because they in no way condemn it. The accuracy test is still to come, and we might get a big surprise there.

Crosman 2100B multi-pump air rifle: Part 1

by B.B. Pelletier


Crosman’s 2100B is a full-sized multi-pump that hopefully delivers power and accuracy with a few economic concessions.

I’ve been reviewing some basic and even classic airguns and air rifles for the past month, and today’s Crosman 2100B multi-pump is one of them. It was initially my plan to get all these at least started by Christmas 2011, but I didn’t even make that date. Next year, I need to start in early October, because other things do get in the way.

I know many of you are 2100 fans because you’ve said as much in the comments.

I may be the last guest to come to the party where the 2100 is concerned. Only Crosman’s smoothbore 760 Pumpmaster is more popular; and, of course, with the release of the rifled M4-177 late last year, that will be a tough act for any airgun to follow.

Think of the 2100 as the 760′s older brother, though there are a couple very important differences. For starters, this powerplant is completely conventional. You can pump the gun and leave air in the reservoir without cocking it first. That’s a big plus in my book. And the piston stroke in the 2100 is longer than that of the 760, so the power is greater, as well. Best of all, the 2100 has a rifled barrel!

The power level is elevated over that of the smaller multi-pumps. Crosman rates the rifle at 755 f.p.s. with steel BBs and 725 f.p.s. with lead pellets. Naturally, I’ll test both numbers for you, and Crosman Copperhead BBs will be involved. So, this is a more powerful airgun than most of the others in its class.

Sights
The sights are a fiberoptic bead in front and a plain notch in the rear. The rear sight is adjustable in both directions, though the adjustments are crude. There’s an elevator wedge for elevation, and the entire sight can swing in either direction for windage. A screw then locks it in place.

The stock and forearm/pump handle are plastic, but the rest of the exterior of the gun seems to be metal. Only the bolt handle and barrel band are plastic, while the exterior of the barrel is jacketed in some metal around a soda-straw steel barrel. This barrel is rifled, as mentioned, yet the rifle can handle steel BBs if you’re so inclined.

Cocking
The bolt retracts to open a funnel-shaped loading port, similar to what we saw in the review of my vintage Crosman 2200 multi-pump rifle back in 2009. I’ll wait until I’ve loaded the gun several times before reporting on how easy it is to load. Naturally, this time, there are also steel BBs to be loaded from an internal reservoir, so I’ll cover that later as well.

The effort needed to cock this gun is considerable, and buyers should know that before they buy. This isn’t the gun to pick to train your 10-year-old. Think of it as more of an adult pneumatic. I compared it to my vintage 2200, which is much easier to cock, so there’s a possibility that this will wear in with time and use.

Most people love the 2100!
I looked at the owner reviews of the gun, and only one of them was really negative. Apparently, the buyer expected a $125 rifle for $60. He said the barrel is plastic, but it isn’t. It’s metal, but as noted, it’s just a jacket around a soda-straw steel barrel. He was terribly upset about the construction of his gun. So much so that he forgot to report how it shot.

There were 32 others, however, who gave the gun five stars, and I think what they say is a lot closer to the truth. I’ve tested Cannon multi-pump air rifles from Indonesia that are all metal and wood, but don’t shoot worth a darn until their valves are rebuilt by their owners. Even then most of them don’t even perform to spec, and only after they’re made to work at all do the owners discover that the barrels are often less than accurate. I expect more from this Crosman rifle and will be shocked if I don’t get it. A little plastic where it doesn’t matter (and, no, Michael…the one person who gave this a negative review, the bolt handle will not break when you cock the gun — even 10,000 times!) is not a detractor if the performance is there. That’s what this report will determine.

The rifle
Weight-wise, the 2100 is light, but not overly so. At just 4.8 lbs., it lays light in your arms but it doesn’t float the way many similar smaller multi-pumps do. For many people, that’s a good thing. The length of pull is an adult 13-3/4 inches that will work for older kids, as well. The molded plastic stock and forearm are both checkered with large, sharp diamonds that really do grip your hands. Overall, the rifle feels pretty good in the offhand position.

Pellets are loaded singly, but the BBs are poured into a 200-shot reservoir that’s accessed through a discreet hole in the bottom of the pistol grip. Just slide the grip cap to the rear and pour in up to 200 BBs. Pull the BB magazine follower to the rear and lock it in place, then, while holding the muzzle down, shake the rifle from side to move BBs into the 17-shot visible magazine on the left side of the receiver. Finally, release the BB follower. Every time you cock the gun, a magnet on the bolt tip will grab a BB until the BB magazine is empty. It’s possible to have BBs in the larger reservoir and not in the magazine and to shoot pellets single-shot without BBs getting in the way.


The 17-shot BB magazine is located on the left side of the receiver.

Trigger
I measured the trigger-pull with my Lyman electronic scale. The trigger is two-stage with a very short first stage. It’s not adjustable. Stage two breaks very consistently at between 4 lbs., 10 ozs. and 4 lbs., 12 ozs. — as long as the squeeze is slow and consistent. Yank the trigger, and the pull goes over 5 lbs. on the test gun.

Pump effort
I have to comment on the effort it takes to pump this gun, because it could surprise some buyers. Where the 760 Pumpmaster and its derivatives all pump easily, the 2100 does not. It pumps as hard or even harder than a Benjamin 397 multi-pump. I may need to measure this for you. I checked it against my 2200, and it’s close to the same effort for both, so this is probably not going to change.

Hunting?
Yes, and no. Yes to the five percent who can reliably hit a quarter at 30 yards offhand five times out of five. And no to the rest who can’t, but just want an extra-cheap airgun to do what it isn’t made for. And the five percent are also the ones who know better than to try to hunt with such a light air rifle.

Yes, this airgun probably has enough power to take very small game humanely at close range. Unfortunately, too many shooters will try to stretch the distance well beyond what the gun can reliably do. So, please, think of the 2100 as a plinker and not as a hunter.

Overall
This will be another enjoyable rifle to test, because it has so much going for it. No wonder it’s a classic — it feels and handles right!

Benjamin 347 multi-pump pneumatic: Part 3

by B.B. Pelletier

Part 1
Part 2


Benjamin’s 347 multi-pump was sold between 1969 and 1992.

Let’s shoot this old classic Benjamin multi-pump and find out just how accurate it can be. This is a test of a rifle you can’t get anymore, but the Benjamin 397 is a very similar airgun, if you’re interested.

Before we begin
I must first comment on the open sights; because after many trips to the range with the .22 rimfire target rifles I’ve been using for the CB cap test, I was shocked back to reality by the wide open notch in the rear sight blade on the 347. It isn’t a precision sight in any respect, and the rear notch is about three times too wide for the front post. I had to guesstimate if the front post was centered in the rear notch, because it’s too wide to know for sure.

Some readers might be inclined to mount a scope or a red dot sight on a rifle like this, but I’m not going to. It has always seemed to me that a rifle like this was meant to be shot with open sights, plus the mounting methods for optics on these multi-pumps leave something to be desired. The mounts can flex the barrel solder joint, eventually breaking it. There’s no good repair when that happens.

I also want to comment on the trigger. Compared to a modern “lawyer” trigger, this one is downright decent. Oh, it isn’t super-light, nor is it especially crisp, but it still breaks at less than 3 lbs., as we discovered in Part 1 of this report; and that’s a trait I like in a sporting rifle. I wish all modern airgun triggers could be this nice.

I decided to shoot at 10 meters, partly because I didn’t know what to expect from this rifle and partly because this is a sporting rifle, after all. It isn’t supposed to be a 50-yard tackdriver.

This rifle does have one quirk. The pump link is loose at the pump handle; every time you pump the rifle, it shifts position with a click. That could easily be fixed with a new link and bushing.

Accuracy
The first shot was offhand from about 15 feet to establish that the pellet was going pretty close to the point of aim. It was, so I moved back to 10 meters, where I rested the rifle for the test.

The first pellet tested was the RWS Hobby wadcutter. The 347 is a .177-caliber rifle, and in that caliber the Hobby weighs just 7 grains. I decided to use five pumps per shot, which is enough to shoot even farther than I was for this test.

After the first test shot, I figured that the pellet would rise a bit at 10 meters, and it did. Since the rifle has no scope, I used binoculars to verify that the pellet was hitting the point of aim, which was a six o’clock hold on a 10-meter rifle bull.

The shots were landing slightly low and to the left, but they were within the bull, so I left the sights exactly where they’d been.


Though they landed a little left, these 10 RWS Hobby pellets went into a group that measures 0.458 inches.

Next up were Beeman Kodiaks. I’ve found over the years that these heavy pure-lead domes usually perform well in multi-pumps. They are one of my “go-to” choices. As before, the gun was pumped five times.


Ten Beeman Kodiak pellets went into this group, which measures 0.558 inches across. That’s one-tenth larger than the group of Hobbys.

For some reason, this rifle didn’t like the Kodiaks as much as I thought it would. They made a slightly larger group than the Hobbys, but I thought it would be just the other way around. This is still a good group, but it isn’t as good as I expected.

The final pellet tested in the 347 was the Crosman Premier lite. Where the other two pellets had some resistance upon entering the breech, there was none with the Premier lite. It went in like it was made for the rifle…which it is, in a way.


Finally, I got the performance I was looking for! Ten Crosman Premier lites made this 0.39-inch group. You can see that the dime will cover the group easily. This is the pellet for this rifle!

Because I’m shooting 10-shot groups, I don’t have to keep shooting group after group when the results are good. Ten shots eliminates a lot of the randomness of a 5-shot group. To put it simply, it’s far more difficult to shoot 10 shots and have all of them be right than it is to shoot just 5.

So, the 347 is a shooter, just as I thought it would be. It’s right in there with all the other good-quality multi-pumps.

One other thing to note is that the points of impact for all three pellets were remarkably close. Hobbys being very light and Kodiaks being on the heavy end should have spread these points of impact more than you see; but this was shot at close range, and a pneumatic is less influenced by pellet weight than a springer. That’s something for hunters to bear in mind.

The bottom line
A vintage multi-pump like this one has a lot going for it. It will have a much nicer trigger than contemporary models; and unless it’s been abused, it should shoot just as well as a modern pneumatic. With all the aftermarket support that is available for rifles like these, you can be sure they will be doing their thing for decades to come.

Just remember to oil the pump piston head with Crosman Pellgunoil and to store the gun with a pump of air at all times.

Benjamin 347 multi-pump pneumatic: Part 2

by B.B. Pelletier

Heads up! Before you read today’s blog, I wanted to alert you to a special scope deal Pyramyd Air is running through GearHog.com. For one day only, they’ve slashed the price on a Leapers 4×32 compact scope with rings. The scope goes on sale Wednesday morning (9/21/11) at 3:00 A.M. Eastern. I can’t say for sure the exact minute that evening when it’ll go back to the regular price, so be sure to order early if you want it. Click on the Gear Hog link to get yours. There’s also an order limit of 2 per person. Now, on to today’s blog.

Part 1


Benjamin’s 347 multi-pump was sold between 1969 and 1992.

Today will be a “Grasshopper” day, as in basic learning. We will transition from “Wax on. Wax off” to learning a few basic offensive karate moves — metaphorically speaking.

I’m going to demonstrate today how I assess the firing condition of a new (to me) multi-pump airgun. This is a drill you probably should be using with all your multi-pumps when you first get them — new and used, alike.

Today’s lesson requires the use of a chronograph. My choice is the popular Alpha model Shooting Chrony that costs right at a hundred dollars.

The first thing I do is cock the gun and shoot it to release any air that might still be inside. Hopefully, there will be some; but with a used gun, the chances of that happening are less than 10 percent. From this point on, though, you should always store the gun with one pump of air in it if the mechanism allows you to do that. Some guns, like the Daisy 22SG, are designed so they cannot be stored this way, but the Benjamins and Sheridans still can; they should always be stored with air in them.

The next step is to pump the gun to the maximum, which with most modern Benjamins is eight pump strokes. Then, load a pellet and fire it through the chronograph. I always use the Crosman Premier pellets for this; and with the .177 guns, I use Premier lites. With the 347 in this test, I got a velocity of 646 f.p.s. on eight pumps.

According to Crosman literature, a new Benjamin 397 should get up to 800 f.p.s. with the maximum number of pumps. That would be with the lightest pellets, so figure a max with Premier lites of around 750 f.p.s. I happen to have a Benjamin 397 in great condition, and it gets 748 f.p.s. with Premier lites on eight pumps.

So, the 347 I’m testing is a bit weak. However, it’s not as bad as it sounds, because the bolt on the 347 doesn’t have an o-ring sealing it like the 397 does. It might never have been quite as fast when it was fresh, due to a small air loss at the breech upon firing. Not that metal-to-metal seals can’t be absolutely airtight, because they can. But on a high-rate production gun like the 347, the time needed to assure a good seal cannot be taken; while it’s good, it isn’t perfect.


The Benjamin 397 bolt has an o-ring to seal the breech.


The Benjamin 347 bolt seals with an angled metal-to-metal contact. It’s less airtight.

The comprehensive test
Now we’re ready to comprehensively test the subject rifle. There are several different ways to do this, but the one I’ll show you is pretty quick and also very thorough. I’m going to pump the rifle to a different number of pump strokes and record three shots at each level. After I finish the maximum number of strokes, which is eight, I’ll pump the rifle additional times and shoot through the chronograph. After every one of those shots, I’ll cock the gun and fire it to see if any air remained in the gun. When I get to the point that air remains, I’m finished with the test.

Pumps–Velocity
2            404, 416, 408
3            488, 489, 485
4            546, 540, 545
5            582, 578, 578
6            609, 614, 616
7            644, 639, 641
8            666, 656, 668
9            678 No air remaining in gun
10          700 Air remaining in gun

The test was stopped at this point, because the gun’s valve cannot handle 10 pump-strokes worth of air. That doesn’t mean I’ll be filling the gun to nine strokes, either. It simply means the gun is a little tired and the valve can handle more air than the eight strokes I’m currently putting in it. But pumping to a higher number of strokes puts more stress on the pump mechanism; so if you want your air rifle to last for decades, don’t exceed the maximum recommendation. However, if you absolutely must have the last foot-second from the gun, then this one needs an overhaul.

Personally, I’ll keep on shooting it as it is, because I don’t need this gun to be a magnum. I have other airguns for that.

Shot string analysis
Let’s look at the shot string and see what we can learn. First, notice what huge jumps in velocity you get when advancing to pump strokes three, four and five. Those large increases start tapering off after five strokes, and the additional strokes only boost the velocity a little. The jump from four strokes to five is about 34 f.p.s.; but from seven strokes to eight, it’s just about 22 f.p.s. We’re stressing the system more for a smaller boost in velocity.

Next, notice how the rifle stabilized and gave very tight velocity variances on pumps three through seven. Apparently, it likes that range of pressures.

After the test
After the shooting was finished, I went back and shot one more shot at each number of pumps to see if the results still agreed with what I got when shooting the strings. What I’m doing here is canceling any bias from the gun heating up.

Pumps–Velocity
2            411
3            483
4            539
5            581
6            610
7            642
8            659

Comparing these numbers with what was seen in each of the strings, I’d say the rifle is shooting in the groove and there’s been no heating up from use. However, the first shot on eight pumps differed from the string on eight pumps, so the gun does need a couple shots to warm up in the beginning.

One other test
One final test, and I’m finished testing this rifle. When I bought it from a pawn shop several weeks ago, of course there was no air in it. I immediately put in one pump and have stored it that way ever since. When I started this test, the first thing I did was cock the rifle and shoot it, to see if there was still compressed air inside. And there was! That means it held air for over a week.

For the rest of the time I own this rifle, I’ll test it from time to time to see if it ‘s still holding that pump of air. My Sheridan Blue Streak, which was new in 1978, has been stored with a pump of air in it since new and it still holds air indefinitely. I’ve shot it after storing it for over a year, and there’s still air inside. It’s lost about 75-100 f.p.s. velocity since new, but it still holds air; and that means the valve is still tight. My Crosman model 101 .22-caliber multi-pump rifle, which was built in the 1940s and was overhauled about seven years ago, has held one pump of air for as long as two years, which is as long as I’ve tested it so far.

Do you notice that I only used a single pellet for today’s test, and that I ran the test differently than usual? Multi-pumps are different guns and have different things to watch, so this kind of a velocity test is better-suited to their design quirks.

Benjamin 347 multi-pump pneumatic: Part 1

by B.B. Pelletier


Benjamin’s 347 multi-pump was sold between 1969 and 1992.

The Benjamin 347 is a single-shot, multi-pump pneumatic made by the Benjamin Air Rifle Company of St. Louis from 1969 through 1992. Most of what I will say about the 347 (the .177-caliber version of the gun) also applies to the .22-caliber model 342.

There are two variations of this gun. The model I’m testing for you today is the first variation. It is characterized by a checkered pistol grip and forearm and was made from 1969 until 1986. The second variation has a plain stock and went from ’86 to ’92.


This closeup shows the checkering on the 347 pistol grip. Not great, but what do you expect?

This is the model that took Benjamin out of the old days and into the modern era, where the successor models 397 and 392 took over and remain current today. The rifle just prior to this one was the model 317. It was also an underlever pump like the 347, but Benjamin had used the same model designation for an earlier front-pump, pushrod-type multi-pump that was made before World War II.

When I got back into airgunning seriously in the early 1990s, the presence of these two different Benjamin airguns with the same model number caused a lot of confusion; but now that Crosman has brought out the now-discontinued Benjamin Super Streak, a breakbarrel spring-piston rifle, most collectors have gotten used to the idea of model name reutilization.

The rifle
The 347 is generally the same as all underlever multi-pumps that went before and came after its time, but don’t think there are no differences. For years, I’ve told people that a 347 is just an older 397; but now that I have both of them to examine, I can see several differences. The first is the overall length of the gun. The 347 is just under 34-1/2 inches long, while the 397 that I have is 36-3/4 inches overall. All that difference appears in the stock, as the barreled actions are exactly the same length. That’s important, because the length of the barrel determines the maximum velocity the rifle can achieve.

While this is not a report on the 397, I’ll say that the first 397 rifles looked remarkably similar to the 347. Over time, though, certain features — such as where the safety is placed and how the rear sight works — have changed. Today, the 397 is quite a different rifle, though at its heart it’s still a multi-pump with the same capability as all other similar guns.

The pull on the 347 is just 13 inches, which is about 7/8 of an inch less than the 397 and about 3/4 of an inch more than the 397 carbine. I compared it to the specs Mac gave us for the 397C, and it turns out to be just a little longer over all and heavier (at 4 lbs., 12 ozs. compared to 4 lbs., 4 ozs. for the carbine). So, this is a smaller air rifle, yet still sized for an adult.

The safety is located at the rear of the receiver and is a push-pull type similar to many shotgun safeties. It’s entirely manual.


The bolt is just bent from a solid rod. The safety. located behind the receiver tube, is manual and slides in and out. It is convenient to the thumb.

The trigger is another interesting feature. While it’s quite simple in design and operation, it has an average 46-oz. pull-weight and is reasonably consistent (within 3 oz.). That’s under three pounds and quite a bit better than the lawyerly 5-7 lb. triggers we see on multi-pumps today. The blade is very wide and flat and feels good to me.

Sights
The rear sight is adjustable in both directions, though both adjustments are crude. To adjust windage, loosen the rear screw on the sight leaf and push the whole sight in the direction you want the pellet to go. For elevation, there’s a stepped elevator that sits under the rear leaf. I’ll find out how well they work when I test the rifle for accuracy.


The rear sight has crude adjustments for both windage and elevation.

The rear sight notch is very wide in comparison to the front blade. A little extra light on either side of the front blade is good, because it allows you to frame the front blade exactly in the center. But this seems to be too much; and once, again, I’ll find out when I shoot it for accuracy.

The 347 will accept the Williams peep sight, but the receiver isn’t pre-tapped for it. That was a marketing mistake on Benjamin’s part, and Crosman corrected the situation when they took over the company. Owners do not want to drill and tap holes in their receivers, and why should they? Even though the receivers on all Benjamin pneumatics are made of brass that’s easy to drill, it’s an extra step that most people just will not take; but if the holes are already there, quite a number will decide to try the peep sight.

As far as scoping the rifle goes — my advice is to forget it. The intermount that fits on the barrel of a rifle like this is so prone to break the barrel solder joint from flexing it with the extra weight of a scope that it isn’t worth the attempt. My advice is to just use open sights on these older multi-pumps. Of course, there have been receiver bases for the modern Benjamin rifles that change everything, but I don’t know if they’ll work on an older-profile receiver like the one found on a 347.

Maintainability
Though the parts are no longer generally available for an older model like the 347, there are plenty of service stations that are making and modifying parts for these guns. So, they can be repaired and rebuilt. The pump piston rod in the rifle is adjustable for wear. As the power drops off, the pump rod can be turned out (made a little longer) to make the piston head go closer to the inlet valve, thereby pushing more compressed air into the valve/reservoir when the rifle is pumped. It’s not a means to hot-rod the gun, but to tweak it back to original performance when it gets a little tired.

Naturally, the best maintenance for any airgun like this is to keep the pump head moist with Crosman Pellgunoil, which helps it maintain a seal against the walls of the compression tube when it moves. For long-term care, leave a pump of air in the gun when it’s stored. That seals the valve against airborne dirt that can quickly destroy the seals. A rifle thus stored can be expected to function for many decades.

My pet peeve
The rifle says “Benjamin Franklin” on the left side of the receiver tube. I knew that was a play on the company name when I was nine years old and inherited my father’s model 107 pistol. For some reason that I cannot fathom, adults in their 60s still don’t get it and think the rifle is called a Benjamin Franklin. Nothing sets me off quicker that when someone makes this mistake. Sorry, but you’ve been warned.


The presence of quotation marks around the name, Benjamin Franklin, indicates that it’s not real. It is, in fact, just a play on words. Since the company name is Benjamin, they wrote Benjamin Franklin on all their guns during certain years. There was never a Benjamin Franklin airgun model, nor is there any other connection to the name.

Another factoid
All Benjamins are made of solid brass. It’s amusing to see one all polished like a trumpet and the owner thinks he has the greatest thing in the world. In fact, they’re all solid brass under the finish. At gun shows, it tickles me to hear dealers talking with pride about their “all-brass Benjamin Franklin” when the guns are still made of the same materials today.

Putting things into perspective
A look at a 347 is a look back into history. This rifle was made when the old Sheridan Blue Streak with the classic rocker safety was made and should be equivalent to it in most ways except power. As a .177, this rifle will always come out on the short side of a power test because pneumatics like to push heavy pellets for greater power. However, velocity will be greater for the smaller-caliber guns. So there’s a balance.

This should be a fun gun to test.

Postscript
Last weekend, I heard a funny line in the new movie Contagion. One of the main characters was a blogger portrayed by Jude Law. A doctor, played by actor Elliott Gould, told him that a blog is just graffiti with punctuation.

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