What IS a good tuneup?

by B.B. Pelletier

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

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

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

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

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

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

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

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

26 thoughts on “What IS a good tuneup?

  1. There is nothing about noise in your todays blog. What can be done to a springer to reduce this nasty bang?

    Alex



  2. He’s right. Much of the noise made by a spring gun is the vibration of parts in the powerplant. The muzzle blast is about 25 percent of the total sound a springer makes.

    B.B.



  3. I JUST GOT A NEW W.S. PATIRIOT FROM PYRMID AIR. I’VE FIRED IT ABOUT 20 TIMES AND NOTICE IT HAS A HIGH PITCHED SQEEK AND SQUEEL ABOUT THE LAST 10% OF THE COCK STROKE. IS THIS NORMAL FOR THIS GUN WHEEN IT IS NEW? SHOULD I OIL THE SPRING?


  4. KAPSKEY,

    I’d shoot it at least 500 times before doing anything. These spring guns go through quite a transfoprmation during their early days.

    B.B.


  5. Legacy 1000 update:

    Called pyramid today. The tech was super helpful. Unfortunately what he said didn’t matter, as the sales rep said since I’ve been trying to get the guns to shoot straight for more than 30 days, I’m SOL as far as pyramid is concerned. Crosman closes at 4:30pm eastern, so I’m going to take my lunch break tomorrow to deal with it. I’m sure all they’ll tell me is that they’re going to ship me another pair of Legacy 1000′s, but who wants a pair of guns with a defective design? I really wish pyramyd had done like the tech said they would and offer me a store credit, as I was wanting to ditch the springers and jump to some british PCP’s (seems like they’re worth the dough, from what the users say…). Now I’m probably just be stuck with two replacement guns that also suck, unless Crosman has taken any notes from Diana or the other GOOD springer manufacturers…

    -David “I can’t hit a coke can at 10 yards” Coleman





  6. i was looking down the breech of my rifle one day, putting a pellet in and cutting the lead with my fingernail. no particular reason, just wanted to see how soft it was.then, of course, it hit me. now, i dont own one, nor do i plan on buying one, but wouldnt loading lead balls in the magazine dent each side of the ball, like the early daisy bbs you describe? and if so, dosent that affect accuracy/feeding?
    the drozd sure is a strange gun.


  7. dm20
    You would have to use significant force loading to dent a lead ball enough to affect feed or accuracy, as the spherical shape helps prevent accidental deformation. The more you deform it, the larger the bearing surface. And you would need a bit more force than is comfortable to cut them any real amount with a fingernail, too. I just tested that out and it is far from impossible, yet not something I would do to pass the time.
    And a co-worker of mine has a Drozd, and about 2,000 rounds through the pipe chasing rats at night have fed through fine, according to him. Yeah, I know, innapropriate weapon for rats, but he’s like that. The loon even has a night sight on it, go figure.


  8. dear davidandjemma,
    i take it that you either didn’t read my post on my legacy 1000 or you choose to ignore it.
    in all fairness to Pyramyd Air, their warrenty is for one year, NOT 30 days. for the problems you report, i am sure they would exchange your gun for another. your rifle is defective. my 1000 is relatively accurate and has never had the pivit bolt back out. other than a cocking effort of 38 lbs, a 800 lb. trigger and an over all weight that makes one handed free shooting very, very difficult, this is a wonderful springer, in .22 cal, at the best price on the net.
    what have you got to lose by letting their shop take a look at your rifles. i am still available to receive your two legacys should you and Dad want to dump them. Return postage garunteed!


  9. BB I’m a litttle unclear about what the difference is between “firing jolt” and “kick”. I’m new to springers so I’m still trying to sort out all these new sensations.


  10. Firing jolt and kick,

    Kick is movement of the gun, also called recoil. On a spring gun, the recoil is in both directions, with the forward kick being the strongest.

    Firing jolt is a term that referrs to the high-speed vibrations when the gun fires. The gun may not move, but the shooter will feel a pulse of energy when the gun fires.

    This is very difficult to imagine. It becomes clear when you fire a spring air rifle. They all do it to some degree.

    B.B.


  11. dm20,

    Why would a perfectly round hole dent the opposite SIDES of a spherical lead ball? Why wouldn’t it just put a ring of contact around the circumfrence of the ball, like a muzzleloading rifle sometimes does when it’s loaded with a round ball?

    B.B.


  12. Round ball denting?

    hmmm, if the roung ball is lead we can assume it is of a specific caliber and probably of accurrate dimension as well, be it in .177, .22, or what ever.

    I can’t see how deformation of the correct size ball for the caliber of rifle shooting it could be.

    I shoot them in .177 when I need more penetration for the target and never had a problem loading where enough force to ‘dent’ would be needed.

    Am I lost on the subject, or am I missing something in the question that dm20 presented?

    dsw


  13. cold shooter,

    There was some confusion when I talked to people at Pyramyd yesterday. I took my lunch break to deal with it and they were very helpful in figuring out an acceptable solution. I’m going to be sending the guns back as soon as my dad gets back from vacation, and we’re going to be shopping for some PCP guns (and pumps) I suspect. I’m going to be doing some research, but I’ll be posting some questions on here and asking Gabe at pyramyd when I’ve narrowed it down and have some intelligent questions. So unfortunately, I can’t send you the bum guns. But I’m glad to hear you’ve had much better success with yours than we’ve had with our pair here. Maybe it’s the Florida weather?

    -David


  14. Hi B.B.

    This might sound nuts, but I just had a bit of fun sighting in my new Benjamin 392. I received the rifle from Pyramid a couple of weeks ago and got a chance to shoot a crow that were hanging out in the cheery tree in our backyard from about 20 yards. I’m embarassed to say that I’m not really sure that I hit it because it flew away (only used four pumps). But I do know that since taht time there hasn’t been any crows coming by for a visit.

    I’m finding that this airgunning thing is a bit addictive. As a technical writer, I work from home most of the time. Sometimes for a break, I’ll take the 392 and do a little plinking for about 10 rounds. Since the crow episode, I also find myself hovering around the backdoor, looking out the window to see if any crows are hanging out in our trees, hoping that I’ll get a live target to shoot at. (The squirrels that live in the yard, and the racoon that occasionally stops by in the morning, are off limits.)

    Well, today I was surfing your blog on how to sight in open sights. Sighting-in at 10 feet was easy; at 10 yards, a little more difficult (I think I need new glasses or maybe a scope or red dot.) It was a fun and relaxing. Like sailing, shooting is all about the mind and body being in tune with the gun and the environment around you. You make sure that everything is safe, and that you concentrate on your technique: posture, sight picture, “cheek weld,” and trigger pull before taking the shot. All this thought and action takes place in the moment. For that moment, nothing else matters. You’re totally focused. It’s a nice break from sitting at a computer, writing about software all day.

    I think, eventually, I’m going to want to get something with a little more power. Probably an RWS 48 or 52. Gotta wait for an opportune time to approach my wife before I make the purchase. It may take a few months. But, in the meantime, I’m sure I’ll enjoy the 392. It’s accurate, and I appreciate the multi-pump feature. Oh yeah, I’m driving down to California (from Seattle) to hook up with an old school friend who just purchased his 392. We’re going to do some shooting and relive some old memories from when we used to own Sheridans when we were in high school in the ’70s. Probably smoke a couple cigars as well.

    Anyway, just had to mention all that, and wanted to say thanks for all the good posts on your blog.

    Cheers,
    Steve




  15. Ben,

    The Diana model 6M is not rare. It may be scarce in some parts of the world but never rare.

    Diana recoilless guns had a problem with their seals. They disintegrate after several years. The problem has been fixed, but I’d make sure the gun you buy has good seals because replacing them is difficult. Both pistons have to be indexed to make the anti-recoil system function.

    A 6M is worth $250 in good condition.

    B.B.


  16. Do you have any rules of thumb to offer for selecting a pellet which won’t allow the piston to bottom out? I would assume you wanted to go heavier if you were experiencing bottoming out.


  17. The only rule I follow is to avoid junk or novelty pellets (Gamo Raptors) and to stop shooting any pellet that makes the gun detonates.

    B.B.


  18. B.B.,

    You refered to the Diana 54…

    Is that rifle easier to shoot accurately than the TX200 due to the recoil system? Is the difference in ease great?

    Thanks



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