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.

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 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.

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.

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.

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.

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.

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.