Benjamin 310 BB gun: Part 6

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3
Part 4
Part 5

A history of airguns

Benjamin 310
A Benjamin 310 multi-pump BB gun from 1952.

This report covers:

  • How to test?
  • RWS Hobby
  • H&N Baracuda Match
  • One pump
  • Another test
  • Fastest shot
  • Pellet tests coming
  • One final test
  • Summary

Today is our final day of looking at the velocity of the Benjamin 310 multi-pump BB gun. You will recall that the reason this has taken so long is because this gun is very flexible about the ammo it accepts. If it turns out to be accurate, this gun may well be an all-time best airgun to own — right up there with an FWB 124 and a Diana 27..

Today we will look at the velocity with pellets. Since the gun is smoothbore I don’t expect it to be accurate past 10 meters, but I will reserve judgement until we test it. If I get nothing better than 2-inches at that distance, though, I won’t be testing it at 25 yards. There are already enough holes in my walls and woodwork!

Multi-pumps are pneumatics and pneumatics handle heavier pellets quite well. Therefore I need to test a heavy pellet as well as a lighter one.

How to test?

To be honest I am so far outside my comfort zone with this gun that I have to read my own past results to figure a way to test it with pellets. Here are some things I have learned.

This gun tops out at 5 pumps. I have seen that repeated so many times that I can accept it as a given. So, with a light pellet and also with a heavy pellet I will test it with 2 to 5 pump strokes.

I know the air is not exhausted on the shot from even two pumps, so I will exhaust all the air after each test shot. I’m doing that just so we know for certain that the velocity we are seeing is only what is obtained from the pump strokes listed.

I will also test it with one pump and shot, followed by another pump and shot without exhausting the air. From past testing we know the velocity will increase to a certain point and then stabilize around that point. I think I will test this with the light pellet, only because I don’t want to get a heavy pellet stuck in the barrel, though as I have said this gun is so simple that it’s easy to clear.

One last thing we learned about this gun is that when the projectile fits the bore tight it becomes very efficient. So I will watch the fit of each pellet to the bore and comment on it as I go. That may provide some special insight.

That’s all I can think of, so let’s go!

RWS Hobby

The RWS Hobby pellet in .177 caliber weighs 7 grains, making it one of the lightest lead pellets around. I will start with it. This pellet loaded very easily, once the wadcutter head got past the ramp at the ends of the loading trough that leads into the breech. In spite of that, I know for a fact that Hobbys have large skirts. And, since .177 pellets are already larger than the 0.175-inch or even 0.171-0.173-inch balls and BBs the gun is made for, the Hobby fits the bore tight.

Pumps……..Velocity
2…………….473
3…………….546
4…………….627
5…………….640, 578, 395

Wow! I didn’t expect this. The Hobby pellet is actually faster than any of the BBs and lead balls. Notice that the increase tapers off sharply after 4 pumps? I think 6 pumps is still too many for this gun as it is now set up.

Notice also that I kept shooting the gun after the first shot on 5 pumps. I didn’t know why I wanted to know that, but in a little bit it will come into play.

H&N Baracuda Match

Now for the heavy pellet. I shot the 10.65-grain H&N Baracuda Match pellet with a 4.53mm head.

Pumps……..Velocity
2…………….395
3…………….480, 357
4…………….514,422
5…………….531, +1-530, +1-501, +1-471, +1-440

This is the start of my investigation into how to keep the velocity stable, shot to shot. After the shot on 5 pumps, I added one pump and shot again, then again and so on. As you can see, the velocity did decrease. But it gave me another idea that I will tell you about and test in a bit.

One pump

Now I move on to the one pump test. I pump the gun one time, shoot it, then don’t exhaust the air but pump it again and shoot it and so on until the velocity stabilizes. As I said at the start I will do this with a light pellet — which means the Hobby. Here we go.

Pump……..Velocity
1……………305
+1…………..354
+1…………..378
+1…………..386

And then I did something stupid. I was distracted and failed to pump the gun before shooting the fifth time. That messed up the whole test, because the increase is cumulative. No way to start where I left off. Have to start over. And in doing that I saw a close match between the second test results and the first.

Pump……..Velocity
1……………306
+1…………..351
+1…………..382
+1…………..398
+1…………..399
+1…………..385
+1…………..406
+1…………..383

It seems the velocity stabilizes around 380-400 f.p.s. And, based on the tests we did before with BBs and lead balls, I will guess that if I started with 2 pumps and added one after every shot the velocity would drop to the same point. What the heck — let’s do it.

Pump……..Velocity
2……………472
+1…………..466
+1…………..450
+1…………..450
+1…………..427
+1…………..412
+1…………..410
+1…………..399
+1…………..395
+1…………..396
+1…………..395
+1…………..395
+1…………..392
+1…………..393

That pretty much proves it. The velocity decreases to the same point that it increases. This give me a stable velocity for accuracy testing.

Another test

Now I will tell you about that other test I thought about earlier. It occurred to me after I was pumping 5 times, then pumping once after each shot, that the velocity might stabilize at 5 pumps if I pumped twice after each shot. Past testing has shown that 5 is the maximum number as far as velocity is concerned, so let’s see if the gun will stay there by pumping twice after each shot. The next test will be shot with H&N Baracuda Match pellets having 4.53mm heads

Pumps……..Velocity
5…………..…540
+2………..…..540
+2………..…..541
+2………..…..541
+2………..…..545
+2………..…..532
+2………..…..539
+2………..…..543, 540, 471, 314

Okay, that was almost what I had hoped. As you can see, the velocity remained fairly constant for these 8 shots. What you can’t see is that the pump force increased slowly as this string progressed. That’s why I stopped after the eighth shot and fired off the rest of the charge without pumping. It’s easy to see the gun was very full by this point. So this method works for a few shots, but not indefinitely. I may use it in the accuracy test.

Fastest shot

As a final test I decided to see what Sig Match Ballistic Alloy pelletswould do. Because they are so light (5.25 grains) we know they will be the fastest pellets, but they may also turn out to be accurate, so I want some velocity data to go with them.

I know most of you will not pay this much for a pellet to shoot in a smoothbore pump gun, but Sig Sauer has been kind enough to send me several tins of the pellets, so while I have them I’m using them. Florian Schwartz, the general manager of H&N, told me why they cost so much. They are made from pure tin that is extremely expensive

Pellet tests coming

I have a similar Sig target pellet made of lead that they just sent me, so that’s going to spawn a special target pellet test, and they have sent me a couple different .22 caliber pellets that I plan testing for you soon. I also have those new H&N Baracuda FT pellets that Herr Schwartz gave me to test.

For now, though, let’s get back to today’s test. We are now looking at the lightweight Sig Match Ballistic Alloy pellet in the Benjamin 310.

Pumps……..Velocity
2…………….536
3…………….637
4…………….705
5…………….755, 637, 407

Wow! They sure are fast.

One final test

If these Sig pellets turn out to be accurate, will they stabilize in velocity like all the rest. I had to test it to see.

Pump……..Velocity
1……………364
+1…………..411
+1…………..417
+1…………..424
+1…………..424
+1…………..432
+1…………..429

They not only stabilized, they did so at a good velocity for 10-meter target shooting. If they prove accurate, I will have a good handle on them.

Summary

That’s the velocity testing for the Benjamin 310. We now know quite a lot about this airgun and that will serve us well in the test yet to come.

Beyond those tests, though, there is one additional possibility for the 310. I could get a new striker spring for the gun and see how that changes its personality. There is certainly a boatload of baseline test data to compare to!

26 thoughts on “Benjamin 310 BB gun: Part 6


  1. B.B.,

    So they sent you several tins of tin? I had always wondered what those lead free alloy pellets were made of. Probably could be an article for somebody to make. Is there a metallurgist in the house?

    Siraniko


  2. BB
    Alot of work your doing there. But worthwhile. Interesting results.

    And as usual can’t wait for the accuracy test to see how it goes. I’m thinking we are in for a surprise.


  3. B.B.,

    Thanks for all of the work. If they could make a modern, multi-pump pellet shooter that would (guarantee) a 5+1+1+1+1,….. I would be interested. I have always been a fan of the 880 platform/style/pump arm. Adult sized with some upgrades. That would be good seller,… I would think.

    Good Day to one and all,…… Chris


    • Chris,

      You just might have to get you one of those new multi-pumps. She doesn’t have much going for her in the looks department, but I hear she is a really good cook.


      • RR,

        I would be all over an adult sized 880 that could do the 5 + 1 routine. Descent trigger (Maximus tune-able type), decent (read long) scope rail and a magazine. Synthetic stock is fine. Keep it light. Oh yea,… Ambi.,….. including bolt. Done right,… I would go 150-200.

        Chris


  4. BB,

    LOL! You have really been enjoying playing with this old gal, haven’t you? “Let’s think of another excuse, uh test we can do with this airgun.” That’s OK, I understand.

    As for the new hammer spring, I would most definitely check into that. I get the feeling that once this crowd sees what it will do, they will really be drooling after this one.


  5. B.B.,

    I have spent a little time thinking and reading about the Nitro Piston Elite power plant. So, although I haven’t shot one, I have arrived at some surmises. It seems to be an incremental improvement; but then, I think it is fairly obvious. My other surmise it that the B19 platform is still a B19 platform. Could be something like putting lipstick on a pig.
    I seem to remember you had a Lothar Walther barrel made for a B3 once. Perhaps such a barrel could improve on the common B19 barrel (although I know there are variations on B19s. Of course, after purchasing the barrel, it might still be much better to purchase a HW97 or a TX200 or consider a PCP.
    I have nothing against the B19 platform. I have a couple, both Nitro Piston. I even like the NP Elite although I don’t know if the B19 platform and barrel will allow it to show off well. I may never know.

    ~ken



    • Ken
      Funny you mention barrel changes.

      I’m right now getting ready to put a .22 caliber 12″ barrel in my Condor SS. Why? Cause I had really good luck with a .22 caliber Talon SS with that same barrel.

      Plus what I have noticed is the barrels that fit the regular Condor and Talon and Talon SS are a bigger outside diameter and will fit the Condor SS. So I’m hoping my Condor SS will pick up some accuracy with the heavier diameter barrel that’s used in the other small bore AirForce guns.

      I talked about going to the Mountain Air .30 caliber barrel that is suppose to fit these small bore AirForce guns. But I wanted to try this .22 caliber 12″ AirForce barrel like the Talon SS uses that I had a while back. If it proves out good then I’m going to see if the .30 caliber barrel works out.

      If so that makes for a pretty universal gun. And for some reason if I don’t try I feel like I’m missing something you know what I mean. 🙂



        • Ken
          Thank you. And I do have a good feeling about it.

          Problem is. If it’s accurate do I want to take that barrel out to try the .30 caliber barrel. Plus factor in the cost of that barrel and buying some .30 caliber pellets to try.

          At least one thing about it all is the small bore AirForce barrels are easy to change.

          And as it goes. Who said anything good is easy to do. But hey. It keeps me occupied. 🙂


          • Gunfun1,

            Those are the kinds of questions that nag me.

            I must disagree on one point. If manufactured well, and I believe AirForce do a great job, the changing of the barrels will probably be easy and work at least as well as the barrel you remove.

            As you mention, there is the issue of cost for us mere mortals. Decisions, decisions, decisions …

            I can afford the only NP Elite break barrel I have seen, money wise, but not wife wise.

            ~ken


            • Ken
              Yep on manufacturing and yes wife wise and my daughters.

              Don’t know about you. But money money money. It’s like a avlanche. You get it it all built up. Then in a blink of a eye it all tumbles away.

              What’s that saying. Get it while you can or it will be gone before you know what happens.


              • Gunfun1,

                Well no children worries, and my wife is very frugal, both because she always was and more so since a drunk driver ended her career (he was hurt badly and escaped to Mexico later with the help of friends and family; may he rot in a dark hot place.
                We are doing pretty well. I am a month away from 68 and still employed; not looking to stop for another couple of years. B.B. is a year or two older than I am. I don’t have the physical stamina I had in times past, but my mind still functions most days.
                I hope your daughters grow up to be more perfect than an Airforce air rifle.

                ~ken


                • Ken
                  Hope your still happy to be working.

                  I’m done. I’m ready for retirement now.

                  And as far as the daughters go. I see them doing just fine. It’s what the world allows is the problem.


                  • Gunfun1,

                    I am okay. I do purchase two lottery tickets each week, one for Wednesday and one for Saturday (I don’t invest in any other game of chance); I know the odds. Even so, I can afford two per week and who knows.

                    I know and I hope your daughters do well in this world.

                    ~ken


                    • Ken,

                      Best wishes on winning. I live frugal too. Normally I play 1 ticket a week, but got one of each today. Can’t win if you don’t play. I could live the rest of my days on 1 million very well and die with money left over. If winning real big, I would be giving a bunch away. Staying anonymous would be the real trick. I am not exactly a people person (but friendly) and tend to have real short fuse when I get solicited.

                      Take care,…. Chris



                    • Chris USA and Gunfun1,

                      I agree with both of you. And I also don’t feel the need to be greedy. Even just playing the basic Texas lottery, I doubt I would ever receive all of the annuity payments and it would be enough.

                      I also would prefer to remain anonymous, however, if I won such a large amount I expect I would become more difficult than I am. My idea is to set up a fund people could file an application for; something most may not do once they see what is required (nothing fancy, just about like applying for a home loan). And when its gone, its gone. The worst thing anyone could do is just ask me for money. That is an automatic no. That doesn’t mean I wouldn’t help someone. Just means I would make the offer. But, hey, that is all speculation at this point.

                      I don’t even understand the Power Ball setup, the tiers and what have you. I haven’t tried to understand it. I think the winner is going to be cursed (cursed, not cussed at).

                      ~ken


  6. B.B.,

    P.S.

    I know I need to learn how to shoot correctly, do due diligence on all aspects of the rifle, shoot a lot of pellets and a lot of different pellets before spending more cash on new barrels and the like.

    ~ken


  7. B.B.,

    I know and I appreciate you and all you do. I am no fanboy; I look for objective data and you have been providing that since before I discovered this blog in 2011.

    ~ken


  8. When i look at this gun and this report i am reminded how much i like basic multi pump guns & iron sights. So this one is different still to my mind this or even an old 880 and no i don’t collect i just think about it and yes i remember wanting more power, but then that wouldn’t be the same thing any more.

    Off topic a bit, but i have seen tests of the Seneca Aspen, but none of them seem to explore taking the low power lower with the hammer spring adjustment always going for the top end stability. I have been waiting for this affordable self contained PCP since day one and i know i am not alone and i would love to see it tuned low instead of high since it has that ability. Plenty of other things i would love to see like a test of a production line Sig ASP20 or a Marauder running off Co2 like they did at first & my feeling at the time is it would be a perfect back yard quiet gun.


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