Home Blog  
Ammo Beeman GT600 air rifle – Part 2

Beeman GT600 air rifle – Part 2

by B.B. Pelletier

Yesterday, Vince regaled us with one of his recent purchases…a Beeman GT600 air rifle. Today, he’ll show us what he found when he pulled it apart and made it better than new.

If you’d like to write a guest post for this blog, please email us.

Bloggers must be proficient in the simple html that Blogger software uses, know how to take clear photos and size them for the internet (if their post requires them), and they must use proper English. We’ll edit each submission, but we won’t work on any submission that contains gross misspellings and/or grammatical errors.

Here we go!

Part 1

by Vince

The GT600 is about as plain-jane a rifle as you’ll find. Dollars to donuts, the same basic design continues on in the more recent Young model 56 and 90 rifles currently available. Many guns have their own quirks when dealing with the rear spring retainer and trigger assembly, and the Norica is no exception.

Disassembly starts with the typical screws (like umpteen other rifles)…

…at which point the action pops out real easy.

The next step is to knock out the retaining pins. Yes, I said knock them out. No sticking it in a spring compressor. Even with the pins out, the spring isn’t going nowhere (which will become evident momentarily).

I used a punch to start tapping them out.

Next, I tapped them back IN and — and tapped them out the RIGHT way.

As you might be able to see in the picture, the pins are knurled on one side and should be punched out from the side opposite the knurls.

After you’ve tapped out the second pin, the spring will push against and trap the punch, which, of course, is now in the hole where the pin used to be. Push in the trigger assembly a little bit to relieve the pressure on the punch and pull it out.

Release the trigger assembly, and the punch jumps back a bit and stops.

This is where a special tool comes into play. Someday, I’ll make a good one, but this works for now. I quickly hacked it out of a 1-inch diameter piece of aluminum tubing some years ago when I got my first AR1000. It goes into the rear of the compression tube.

My special tool…necessity is the mother of invention.

The forks reach around the trigger assembly and push directly on the rear spring guide. Compress the spring, pull the trigger mechanism out through the opening and completely release the spring pressure. I can’t show you this step because I don’t use a spring compressor and have already become something of a pariah on another forum partly because I had the nerve to describe how I do it. So, let’s just say I use my SUPERPOWERS (and my, uh, above-average weight) to compress the spring. After the spring pressure is released, the spring and the rear guide can be removed.

The pivot bolt simply unscrews.

The barrel assembly separates from the rest of the gun.

Remove the pivot washers, clean everything up and moly paste it before putting it back together.

The barrel is then set aside for reassembly later. The piston that came out of the gun should look familiar to anyone who’s disassembled an AR1000 or Hämmerli 490.

The Beeman GT600 has a one-piece seal that’s held in place with a single screw.

The seal looks in good enough shape, so I’ll just reuse it. But, I’ve got visions of that middle screw backing out while shooting, which would probably cause me to say a bad word and flush the gun down the toilet. So, I took the screw out.

The screw was removed and given a good coat of Vibra-tite VC3. This reddish-orange goop gets put on a clean screw, as shown above.

Let it dry for 20 minutes or so BEFORE reassembling the parts. That solidified red gunk causes something of a friction fit between the inner and outer threads, which then resists loosening. Unlike Locktite, it doesn’t try to adhere to the inside threads, so I really think it works better when those inside threads aren’t entirely clean.

Next, I turned my attention to the compression tube. First thing to do is wad up half a paper towel and cram it down inside the tube. Then, I took a small file and broke the edge of the slots and holes in the tube.

Removing sharp edges with a file.

I don’t have to go nuts (well, over this anyway). All I’m doing is getting rid of the very sharp edges that might slice chunks out of a seal as I’m reinstalling it. I wish manufacturers would do this, as it’s not too uncommon to find factory piston seals that have pieces missing because of those edges.

After filing, extracting the paper towel, and cleaning the tube, I can start putting all the pieces back together. For this gun, I’m trying out a proprietary airgun grease some guy was selling on one of the forums. Never really tried it before (I have no idea if it’s any good), so I decided to use it here.

The subject of proper lubricants for springer guts is one that could easily take up waaaaay more space than I’ve got. As a side note, I’ll delve into it a bit. There are two major areas of concern, and the desired lubricant properties of each is a bit different.

Everyone knows about spring tar. This lubricant really has to do two things: stay put and dampen vibration. It has to be sticky and thick (like the guy writing this blog). But it can’t be too sticky or too thick because it’ll slow down things too much if it is. High-powered guns with their monster springs are less prone to suffering from tar-itis, so they can tolerate something heavier. Rich in Michigan’s stuff might not drag a RWS Diana 350 or Gamo Hunter Extreme down too much, but try it on a Slavia 618 and you’ll get stuck in slow-mo. And, Maccari’s tar, which is thinner, might work well on an RM-200 but be less effective on, say, a super-buzzy Diana 46 Stutzen. So, there’s some point in trying to match the tar to the gun.

The second lube needed is a spring cylinder lube. This is where it gets real tricky. You want something with good resistance to wear under heavy and low-speed loading so the cylinder wall isn’t gouged by all that piston side load during the cocking stroke. But, you don’t want something too thick that’ll get scraped out of the way after a couple of cycles and never come back. You don’t want something too thick because the drag from shear forces between the piston and the cylinder wall will really slow things down when the piston tries to spring forward.

You want something that won’t easily get past the piston seal. Anything that does, of course, runs the risk of going BOOM when the gun is fired. A little of this is tolerable (and not entirely avoidable), but a lot of it isn’t going to brighten your day. You want something that isn’t so thin that it flows right past the seal, and you don’t want it so sticky and thick that the seal can’t scrape it out of the way. Since some of it WILL end up in the chamber, you want a lube that’ll be sticky enough to stay on the chamber walls, where it can’t really burn, and not get atomized into the compressed air — where it burns very enthusiastically.

So, silicone is out. It just doesn’t hack it as a high-load, metal-to-metal lubricant. We need something thick that’s also thin, and sticky without all that awkward stickiness. That explains the plethora of lubes out there, many of which are homebrews with their formulations more closely guarded than our bank account data ever will be.

It’s one of these homebrews that I’m trying out. Since this gun isn’t a magnum springer, I can make do with something lighter on the spring. I’m using this same grease there as well. There’s a real advantage to doing so if it’s feasible: It doesn’t matter if the stuff on the spring gets slung off or if the stuff on the cylinder walls gets on the spring. There’s no intermixing of different lubes; it’s all the same goo.

The front guide…

the rear guide…

and the spring get all gooped up with this stuff.

I probably overdid it. But that’s actually one good test of a lube — to see if it gets in the chamber and diesel — or not — when there’s a lot of it to go around.

The piston gets a good coating as well and then goes in.

Now is the proper time to reinstall the barrel. Don’t forget to fit the cocking link back into the slot in the piston and cylinder! If you try to reassemble the barrel pivot AFTER the spring is reinstalled, you’ll find that the tension on the piston prevents everything from lining up and the bolt won’t go back in!

Okay, so I forgot.

If you forget and find yourself trying to reinstall the barrel after the fact (uh, like I did), there’s a way around it. The holes will not align perfectly but will overlap enough to get the round shank of a #1 or #2 phillips head screwdriver where the pivot bolt goes.

Did it wrong? A phillips head screwdriver to the rescue.

The gun can be cocked like this, which will take the tension off the pivot and allow the holes to line up and the screw reinstalled. But, if the sear lets go before you get the screw in, well, you’ve got a bit of a mess on your hands. So, this procedure isn’t really recommended. Just do it in the right order so you may live long and prosper in the land.

Anyway, this pivot bolt doesn’t have a locking mechanism of any sort, so some of the same red goop as used on the piston seal bolt might not be a bad idea.

After the barrel is installed, the front guide, spring and rear guide get installed — in that order. Putting the trigger back in is a matter of compressing the spring with the special tool and putting it in the way it came out.

It goes in about the same way it came out…but in reverse order.

Compress the spring a bit more (without the tool) and slide the pins back in. Voila! Your action is ready for action.

You’ll notice that I didn’t do anything with the trigger, and there’s a good reason for that. I’ve had a LOT of luck re-angling the mating faces to reduce friction and lighten the trigger-pull. Unfortunately, however, that luck’s been all bad. I’ve found that it’s a tightrope walking the line between nice feel and auto-fire. And, if you DO get on the right side of that line and the trigger wears a bit, be prepared for your sear to go on strike. I know that some guys have had good luck with improving direct-sear triggers, but for now I don’t mess with ’em.

So the action goes back in the stock, and I tend to the last major issue for this gun. Don’t know how it happened, but it came out of the seemingly undamaged box that way.

The rear sight is slightly bent.

This always scares me, because I’ve had NO success straightening these out when this happens. I always seem to break the shaft. Anyhow, I contacted the seller, who insisted that it probably happened during shipping. I’m a bit doubtful about that, but no matter. I can’t use it as is. So, I might as well try to straighten it.

Miracles happen…I fixed the bent rear sight.

Dunno WHY I didn’t break it this time. Maybe, being extra careful to bend it JUST far enough was the key. Glad I was able to salvage that sight, as it’s actually a pretty decent one with not much play and a decent sight picture. With the sight back together, Bee (I’ll call her that just to make her feel better) is ready to spit.

Over at the crony, I tried pumping one of my standard test pellets through it — Crosman Premier Super Points. But not the Premiers I usually use. I’m using Premier pointed pellets that were thrown in with another gun purchase I recently made. Since experience tells me these pellets are useless for accuracy, I decided to use them for chrony testing instead. I don’t want them to go to waste, and they weigh the same as the domed Premiers. When I saw an almost 50 fps spread over 10 shots, I switched to Crosman Premier hollowpoints, and the results were a lot better: 549, 549, 549, 550, 549, 550, 551, 560, 557 and 553.

Eleven fps separate high from low. I can live with that! Now, I have yet another reason to hate those pointed pellets.

Firing cycle is improved and cocking is a nice, smooth 20 lbs., including latching the sear. Trigger-pull, incidentally, comes out to about 5 lbs. of creep-free snap. Well, creep-free except for the shooter, that is, who can be something of a creep at times.

Let’s look at what REALLY counts — making holes in stuff. At 10 meters, I tried 5-shot groups with Daisy Wadcutters, Gamo Match, and (one of my favorite cheapies) RWS Diabolo Basic pellets, all with so-so results.

Then came the Premiers – I went to cardboard-boxed Premiers (7.9 grains). Results were somewhat better until I loosened up my grip on the gun…and she threw a great group of 5.

Bee has stepped up to the plate!

Oh. OK. I think I understand. Bee ain’t foolin’ around! Hard to measure exactly, but my best guess is about .32″ ctc, although it might actually be less. I think we have a pretty good overall picture of the GT600. It’s a crude gun that certainly doesn’t live up to the Beeman reputation – or, at least, the old Beeman reputation – of combining superior design, almost hand-crafted workmanship and high-quality machining together in one piece of airgun art. No, “Bee” only gets one out of the three right.

But it’s the one that really counts. With the poor trigger and overall lower quality of workmanship, the GT600 wasn’t going to bring new glory and prestige to the Beeman line. But it wasn’t meant to at its price point. But, with this kind of accuracy and consistent velocity, it’s sure not going to drag down the Beeman name. It’s a cheap rifle, but a good cheap rifle. Which really makes it a good rifle, period.

Beeman GT600 vital stats:
Weight: 5 lbs., 13 oz.
Overall length: 41″
Pull length: 14.5″
Butt center of gravity: 18″
Trigger-pull: 5 lbs.
Cocking effort: 20 lbs.
Average velocity: 552 fps (with 7.9-grain Crosman Premiers)
Muzzle energy: 5.34 ft-lbs. (with 7.9-grain Crosman Premiers)

author avatar
Tom Gaylord (B.B. Pelletier)
Tom Gaylord, also known as B.B. Pelletier, provides expert insights to airgunners all over the world on behalf of Pyramyd AIR. He has earned the title The Godfather of Airguns™ for his contributions to the industry, spending many years with AirForce Airguns and starting magazines dedicated to the sport such as Airgun Illustrated.

101 thoughts on “Beeman GT600 air rifle – Part 2”

  1. Nice work Vince!I don’t have a spring compressor (i must make or buy one- i am just too lazy to make one )and on my Diana 34 spring preload can be tough especially with a new spring so i never do compressing alone or this can be hazardous job ,i guess that i would not or could not do it without compressor with some stronger springer-i would not even want to try .

  2. My brother has a Crosman Raven rifle, and the part where the “Jam Spring” and the “Alive Jam” go into, broke(so the barrel won’t stay shut). So I need a somewhat inexpensive barrel to replace it with. Is there a .22 barrel that I can put on there that will fit??? Or do I just need to order a .177 barrel through Crosman?? Any cheap places on the internet that have barrels?

    Any feedback would be appreciated.


    • Hi Conor !I don’t know much about Crosman air rifles but isn’t Crosman Raven 600 fps in 177 cal ?I don’t think that 22 cal would be economical – rifle would then have just half of power that it has now in 177 cal.So i think that only option is 177 cal original barrel …

    • Where they go into – I assume that’s plastic? Regardless, you don’ t need a barrel. You need a barrel assembly – including the base block – which looks to be all one piece.

      I believe the Raven is made by BAM (a Chinese outfit), and it MIGHT be the same basic rifle as the Xisico B16 which is available in .22. But 1) you don’t know until you try, and 2) you might not be able to get the part anyway.

      In .22 you could expect velocities in the 400-500fps range, so I’m not sure why you’d wanna go that route. Your best bet might be just getting a replacement barrel from Crosman.

  3. Vince,you did a marvelous job establishing consistent velocity.What could or would you expect as the tune breaks in?? Will the extreme spread normally tighten a little further?

    • Normally it might, but 1) I didn’t replace the seal, and 2) I didn’t hone the cylinder. So there’s not much break-in to be done. Besides, an 11fps spread is pretty tight.

      • Vince,
        Bang up job as usual. Thanks for the inside view of this one. That 11 fps spread is remarkable.

        I can only imagine how the safety police beat you up if you mentioned not using a compressor. About the only gun I truly feel one is necessary for is the FWB 124. Using a spring compressor does give you both hands free to align bits and pieces–as well as the ability to walk away and get another beer from the fridge. I won’t mention that virtually all the spring piston guns are factory assembled without a spring compressor.

        • Never tried a 124. I find it hard to believe that it’s tougher than an MP513… that’s one of the few guns that I honestly wasn’t sure I’d be able to get back together.

  4. Vince…

    A lot of work on a low end rifle.
    I tried to take my Marksman apart once but ran in to the same problem of spring compressing that you did. I figured that I would have to make an adapter for the compressor that would be about like the one you made. I did not feel like going to the extra work or getting covered in tar and moly again when I have much better rifles to shoot.
    I just put a little moly on the sear and in the cocking slot and said to heck with it.

    My 0035 is a bit faster than your rifle, but will not make 600 fps. Trigger is harder than the ones on my better rifles. Very twangy but shoots well. Fun little plinker, but has enough power for starlings.
    Got it at Wallyworld maybe 15 yrs ago. $100. I would say that it was worth the money for a lower powered rifle that is easy and fun to shoot compared to the other junk that I have wasted money on.


      • Poor choice of words on my part.
        ‘Low end’ was intended as lower priced and lower powered. It is very well made compared to much of what I have seen around the local stores.
        I don’t mind what I paid for the 0035 compared to what I paid for a lot of other locally available stuff that cost about the same or a bit more that had some issues that are hard to overlook or fix.


      • Vince,

        I have to admire your ability to do this tune on your gun. I don’t even have the nerve to do that to my one springer. After all it works fine and shoots good. My theory is if it ain’t broke, don’t fix it.

        The term “twang” has no meaning to me as I am at least 85% deaf in both ears and any sound any springer makes to me sounds like just a dull noise. And I don’t know what people are talking about when they say a gun buzzes?

        I have only shot 3 unmodified springer’s and did not notice any difference between them. The guy I traded my R9 to said it twanged and buzzed like crazy. He “tuned” it then put it up for sale. But as far as I am concerned it shot great and was a nice gun.

        I guess you really have to shoot a well tuned gun to notice the difference? And it is my luck not to know ANY air gun nuts like myself who might have one I could shoot. Think I may be the only air gun nut in all of the St. Louis Mo Metro area. Maybe the only one in the whole state.

    • Sorry to go off the topic. I was given a 392. Sent in for rebuild.( Mac 1 steroid) Mounted a Leapers scope on it. After cleaning the barrel twice and double checking scope mounts, trying 3 types of crossman pellets, 3 different gamo pellets and 2 JSB pellets I can’t get any consistent groups.3 -4 inch groups at 20 yards. Ideas anyone?

  5. I;m posting this for Borislav, who sent it to the wrong address:

    Hello B.B.,
    I’d like to tell you about my “10 meters match air rifle”.
    I live in Canada and I speak French, so sorry for my English!
    Long time ago I was 10 meters competitor with FWB 300S.
    Six months ago i decided to build my own 10 meters “cheep” match air rifle and after
    a few hours of research I decided to use one IZH 60. Why? Well it is cheep and it has
    potential : I verified the manufacture site for accuracy and for IZH 61 it was – 20 mm (group size),
    but for IZH 60 it was ONLY 8,5 mm (group size) !!!
    I was impressed and I decided to began with IZH 60.
    I bought one and I changed immediately the sights – I ordered an custom build adapter
    (for the front sight) and one AirForce Front Target Sight and one Daisy Avanti Precision Rear Diopter Sight.
    I put all these things assembled and ….you can see the result.
    For me the result is the same like every other 10 meters air rifle.
    The only problem is that you have to became familiar with the stock and with the “lite” weight of this rifle.
    So finally I’m very happy with my “cheap” 10 meters match air rifle and I’d like to confirm that IZH 60
    is very, very accurate. The only need are match sights and a person to use them .
    It is capable of one hole accuracy from 10 meters every time you put the trigger with right ammo.


  6. Vince,

    I write technical articles all the time for work, and I can tell you, you are a master. It is rare to find that combination of great technical skill together with the ability to put three words together coherently. I salute you.

    I am at that point where I feel myself skating dangerously close to the precipice of actually taking screwdriver in hand and attempting to take a gun apart. Your post has pushed me even closer. I’m tempted to tackle my RWS 350.

    I had one unanswered question from your post: How did you manage to straighten the sight screw? Any special tips or tricks here?


    • AlanL, I wish I could remember! I actually did all the mechanical stuff and pictures last spring.

      I THINK I pulled the windage adjuster out, put it in a vise, and pried up on the ‘low’ side with a screwdriver. The threaded pin is frequently hardened and won’t take a lot of bending without ‘SNAP!’.

  7. I’m looking to install a Red Dot Site on a Diana 52. Is a scope stop needed? Will the Tasco .22 Red Dot for rimfire rifles work or do you need the model for centerfire rifles. Suggestions?



    • Mike,
      You’ll probably need one of the droop compensating mounts like this one:

      You’ll need to use the Weaver base Tasco Red Dot scope with this mount. This combination solves both the barrel droop issue that 52’s are known to have and integrate a scope stop.

    • Mike

      My advice is to not bother with the red dot. Your rifle is capable of much better accuracy than that sight will let you realize. Get the UTG dovetail to Weaver adapter, it is a fine piece of work. You may need the droop compensating one, but maybe not. Then get some 4 bolt 2 piece Weaver rings from Leapers/UTG. With short rings you will have room for a 50mm objective bell, so I wouldn’t go with the high rings.

      Then get a good scope. If price is a major consideration, take a look at the Leaper’s Golden Image


      Another Leapers scope if you want something a little larger.


  8. Vince,

    As usual, well written and very informative. What I learned long ago from you is to send my springers to you for work.

    From yesterday….not surprised you don’t remember working on the krono or old hw50. Neither one was very memorable. I think I traded you an old diana 23 or diana 25 for the tune work on the hw50. Surely you remember working on that beautiful Diana 27 I sent to you?


    • THAT sorta rings a bell – were you asking me to lighten the trigger for you? I do remember the 23 – just put a few through it this morning. Mediocre accuracy, but that’s not the point. Just having an example of that model is the point.

      • Vince,

        You did a lube tune on the Diana 27. The trigger was fine. You mentioned it was one of the finest examples you had seen so thought you might remember it. Ain’t it fun getting old? I’m still looking for my cellphone. I think I might have left it at the restaurant. Help me.


  9. Vince:
    Nothing like seeing a springer pulled apart and worked on.Love it 🙂
    I was theorising a while back about increasing the swept volume of my BAM springer by shortening the rod which runs through the piston and engages the trigger.
    Is the rod usually welded inside the piston?
    What jerked my brain was the GT600 doesn’t appear to have the usual rod but a square cut out in the piston.Is that what engages the trigger mechanism on this rifle?

    • Yes, that’s right. There’s no rod on this one, the sear grabs the edge of the piston.

      That’s not as uncommon as you’d think. The Gamo’s are like that, as is the Benjamin Legacy/Genesis, Crosman Quest variants (Storm, Sierra Pro, etc. etc.), the AR1000 variants (TF89 and a zillion Beeman variants).

      These days, with the extreme variety and availability of more powerful guns I just don’t see where it’s worth a lot of trouble to stroke a powerplant on a lesser-powered springer. There’s a myriad of issues to be overcome… coil bind being a biggee.

      • I’m not saying its worth doing, but I would trade stroke for spring power any time. A lot of people worked hard to “tune” their B3’s, but no matter what spring they stuffed in there, there just wasn’t enough gain to make it worthwhile, it just recoiled more for the most part.

    • Dave, yes, what Vince said. Tube diameter, piston length, spring speed/power, and more variables come into play with “power up” mods.

      Couple those variables with the cost of a very good spring and the other parts and… you might just want to buy (used?) the gun you want the BAM model to be?

  10. Vince and Brian:
    It’s OK,all my fiendish plans for the BAM are now in the past after I got the new rifle but seeing the piston on the GT600 it reminded me of a question I meant to ask ages ago.
    Thank you for the good advice.

  11. Vince

    Whaddaya trying to do, kill somebody? 😉

    Between you and Derrick throwing back beer after beer, I’m surprised mainsprings aren’t flying across this country all willy nilly.

    Great blog, as usual. Love to read your stuff.

    It’s is such a shame you live in a state with such draconian and unreasonable airgun restrictions, which keep so many from enjoying your talents. What about spit balls, they got any statutes on spitballs there?

    • Vince,

      Slinging Lead is right– move to South Florida. It’s nice here now– the ladies have all broken out their fur coats against the bitter cold– it’s actually dropped to 75! Nice shooting across my backyard, no having to squint against blinding snowdrifts…


      • AlanL

        Always there to rub it in huh? Let me ask you, does it ever get annoying fishing golf balls out of the pool out back?

        Good thing I’m way up here, where you can’t see my evil eye.

        • SL,
          How the heck did you know?? I’ve gotten so good at it it only takes me a three seconds and a practiced twist of the wrist with the pole net. Over the last 18 years I have accumulated one entire large-size recycling bin full of golf balls and replaced two of my Florida Room windows twice. Any idea what I can do with about 1000 used golf balls? (They do not make good targets, unless you want a pellet right back in your eye.)

          • AlanL

            I have a very good idea what do do with them. Have you ever checked what a sleeve of Titleist golf balls go for? I’m thinking there might be even more airguns in your future. Put up a sign on your fence.

            On the other hand, if they ended up in your pool, it is likely the balls were hit by hacks, in which case they will have been cut pretty badly by the leading edge of the club because of too high a stroke. Gotta weed those out.

            As to what to do with the ones you can’t sell. When I was I kid I used my fathers hacksaw to cut off the plastic dimpled cover. Then there is about 1000 yards of very thin rubber band wound around a pink ball about the size of a grape. Then I would take the ball and put it in my dad’s bench vice and squeezed it until it exploded, releasing a liquid that looked like coconut milk. I have no idea what drove me to do this. It was probably because I wasn’t allowed to own airguns.

            • My kids used to try to sell them like that, and lemonade too, but a 6′ high chain link fence and a thick ficus hedge kind of preclude that now. But even now’ too many balls land in my yard. 2-3 per weekend, at least 4 per week. I just figured out that equates to well over 3500 balls in 18 years, so maybe that’s how many I have. Pink balls and coconut cream inside, huh? Interesting…

              • Sort your golf balls into specific types (titleist makes 15-20 different models) and sell them on ebay. If you want to sell them all at once contact a wholesale, used golf ball seller (google is your friend). Strong market for used golf balls, especially if they haven’t been under water. Those that are recovered by divers on golf course lakes also sell well but at a discount. Golfers may not play with them but will use them in a shag bag for chipping practice.


                • Kevin,
                  Thanks. Be an interesting activity for the kids- like sorting old pennies for rare dates. 95% of my balls do not fall in the pool but into the yard, and many look brand new when I pick them up. I will follow your advice.

  12. Vince,
    Looks like it worked out pretty well — just need to find a cheap pellet that works that well in it :). Maybe the copperhead wadcutters — they seem to be the yin to the Daisy wadcutters yang, i.e., if one doesn’t work, the other usually does.

      • Vince,
        I’ll keep an eye out for them — my Walmart carries a kaleidoscope o’ varieties, as in ever-changing and mostly useless, but you never know; otherwise I’ll order some from PA next time. I’ve noticed that Basics and Hobbys tend to favor different rifles, also, so Hobby might work in your Norica. 20 yards is all I ever shoot with the 490, except for trick shots :).

        • No problem, BG Farmer. I’m able to find these Beeman coated wadcutters at Kmart. Try a tin and see if you like them. I have found some pretty low prices for them online.

          Good luck,


    Tomorrow is start of the 3 day weekend.

    Garage is warming up, the TF79 and Walther Lever Action are standing-by along with the P17 and Crosman 2240 Custom.

    3 days of killin targets!

  14. Vince,

    Once again, thank you for a most informative, well written and illustrated blog. I wonder how many folks will now pick up a screw driver and say, “Looks like I can do something like that myself. Think I’ll pull out the old ….and fix her up”?


    PS How about a link to developing SUPERPOWERS instead of building a spring compressor.

  15. Okay, I’ve got a RWS 34p in .22 cal that only goes 650 fps. So I know how to take apart and put back together breakbarrel rifles, but as far as oil goes, I’ve only got some Crosman Pellgun Oil, and some Crosman Silicone Chamber Oil. If I take apart the gun, do I wipe everything down and smear Pellgun oil over everything? Or is there some oil or grease that I should put on instead that I can buy at Ace Hardware?


    • Conor, did you see this blog from a while back?


      I’ve serviced a number of 34’s, and NONE of them had a properly shimmed seal. They ALL picked up some velocity, some over 100fps.

        • With regards to shimming – the 350’s I’ve worked on didn’t have the same breech seal issues for some reason, although it uses the same parts. But I’ve heard others report that they have. So I suspect it’s not as prevalent on the bigger rifle, but still a possibility.

      • Vince,
        I’ve seen the article, but haven’t read it till just now. Are the shims hard to come by, or will my hardware store likely carry them? If they don’t, will a regular washer for bolt and nut work(a small metal one)?

        • Conor – you can make it yourself DIY ,you can use thin plastic -drill a hole in it and then shape it with scissors or use fishing reel shim -that’s what i did.It doesn’t have to be perfect only thing is that it has to be thin

        • Nope. Mcmaster has some fiber washers that’ll work, but I believe they’re available in one thickness only.

          It’s easier – especially if you’re just doing one gun – to get a punch set like this:


          The shim needs to be about 1/2″ OD and 3/8″ ID.

          and make your own out of some card stock, or something like that. The breech seal itself is essentially a #109 Buna-N O-ring, which should be a hardware store item.

    • I personally wouldn’t use any kind of oil in chamber(it will cause dieseling) ,it is better to use grease(i use plain mechanical grease with high flash point)-it will stay where you want it to stay whereas oil will splash all over piston seal ,lubrication of Diana/RWS piston seal just isn’t necessary and can cause dieseling(Diana piston seals are self-lubricating)

      • Vince,
        Thanks for the info. Last night I cut a shim from an old Whipped Cream lid. The breach seal sticks way farther out now! 🙂 I’ll have to shoot it later today and I’ll let you know if it worked.

        So from the info you gave me, I’ll just leave the insides of the gun alone. Right?


        • Conor you should lubricate piston ,spring but avoid grease to get on piston SEAL (if it does happen it will cause small amount of dieseling but it is nothing serious-shoot heavy pellets ) ,also lubricate chamber but first put back piston with piston seal all the way to the end of chamber then grease about half of the chamber (when you cock the rifle you don’t want to swept grease with piston seal )and yes use high flashpoint grease Happy New Year!

          • Milan,
            So shooting at a piece of board at 35 yds, the pellet without the seal went in about halfway into the board. Then I put the shim in that I made and when I shot(I was aiming at the board,) the pellet hit the dirt in front of it. I was finally able to hit the board(aiming way above it), and on the second shot, it went all the way through the board. But wouldn’t a gun that increased in speed(with the shim), shoot higher in the scope instead of lower, then the pellet without the shim???? I didn’t touch the scope it is still sighted in for 35 yds.

            Then I brought the board up to 10 yds and shot with and without the shim. Both JSB 13.43 gr. pellets lodged into the board, but it looked like the pellet with the shim went in a little bit farther.

            p.s. It was 19 degrees F here when I did the test. Would it have made a difference if it was warmer?

        • Conor, speaking as someone who had to do the same thing on my RWS350, put generous amounts of silicone oil around the breech. When you fire your 34, if you see a nice spray of oil erupting from around the breech, you know the reason for your low velocity. With shimming the o ring, that should take care of any leaks but, you might have a slight tear in the o ring which will require replacing. A #209 O ring will fit nicely. If you don’t have any, get back to me off line and I’ll send you a half dozen. Cyclealleyriders@gmail.com.

          Fred PRoNJ

            • Thanks for correcting me, Vince. Of course, the 109. Conan, it’s possible that shimming your breech perhaps increased the “droop” of the barrel, something Diana’s are notorious for. Hence the reason you are shooting lower than before. Just a thought but it sounds like your penetration testing is proving the worth of the shim in a resulting higher power.

              Fred ProNJ

              • Fred,
                I just re-sighted my gun with the shim in it, and the penetration is about the same as it was!!! 🙁 Now I’m not sure what to do, I guess I’ll have to be content with a .22 that goes around 700 fps.


                No problem about the typo, I get it all the time;-)

                • Conor-do you have a chrony?If not you can’t really know velocity of your rifle just by shooting at wood- wood itself is not consistent material and density can vary ,one way to compere power or see is there any improvements in terms of power/velocity of your rifle is by using consistent material like ballistic jelly (quite a simple thing ).Do it if you have a time.Here is link with recipe -again 🙂 http://www.myscienceproject.org/gelatin.html (use plain cooking gelatin at you disposal and use a lot ) Happy new Year!

                  • Milan,
                    No I don’t have a crony, mostly because they’re expensive. When I first got my gun, @ 35 yds the pellet was going through the same board that I was shooting at yesterday.

                    Happy New Year to you too.

      • Milan,
        So if I want to grease the chamber(where the spring is???), we farm and have plenty of grease(to grease bearings on our machines and equipment), you’re talking like grease from a grease gun? How far up should I grease in the chamber and how thick? Should I grease the spring too(if so, how much)???

        Sorry for all the questions, but I really don’t have any desire to ruin my gun! 😉


        • Conor,

          Never use tractor grease in a spring gun. The closest you can get is when lubricating a lower-powered spring gun like a Diana 27 you can use lithium grease.

          For the powerful guns you want to use a specially blended grease that has a high amount of molybdenum disulphide particles. In other words, a grease made especially for lubricating spring guns.


          • B.B. i use lithium grease for all of my rifles -bought it on the gas pump 😉 flash point at 226 F ,(for lubrication from outside i use Ballistol ) and can’t really complain-no grease on piston seal-no dieseling,some people use Honda motorcycle molly -i am here to learn and i am learning every step of the way but am i doing something wrong unknowingly !?

            • Milan,

              Today most airgun tuners think that lithium grease is best for guns that shoot at 600 f.p.s. and below. It should be okay on your CZs but perhaps not on your Diana 31/34. You may want to find a source for moly grease for that rifle.


        • Conor -i don’t want to talk much about grease because you should probably listen to B.B. i am more DIY kind of guy so i like to take a risk sometimes but unfortunately with limited knowledge 🙂 (i should have probably said right away that i use lithium car grease sorry )

  16. Oddly enough I pulled the action out of the stock of a Marksman 0035 yesterday preparatory to doing a mild tune on it. The main goal will be some careful trigger work, bore-pasting the barrel and a simple debur & relube.
    This series appears to be a very short-stroke powerplant—-@ 2 5/16″ if my rough measuring was correct. So I’ll accept what it will give me in power but if accuracy fails to appear it’ll go to a new home before much longer!

  17. Hey i noticed you didnt include any pics /guides/ info on removing the actual trigger mech…

    i was able to get everything else aprt but i cant get the trigger out for the life of me

    • Eli, look at the 6th picture – the one that shows my homemade tool inserted into the rear of the spring tube. That tool is used to compress the spring an inch or two, at which point the trigger assembly just lifts out.

  18. Thak you for this article. I picked up a Marksman 0035 and it looked exactly like the GT600 inside and out. This article was VERY useful in helping me tear down my first springer. All went well and it is shooting in the 550ish fps range with Crosman 7.9grain pellets

Leave a Comment

Buy With Confidence

  • Free Shipping

    Get FREE shipping on qualifying orders! Any order $150+ with a shipping address in the contiguous US will receive the option for free ground shipping on items sold & shipped by Pyramyd AIR during checkout. Certain restrictions apply.

    Free shipping may not be combined with a coupon unless stated otherwise.

    View Shipping Info

  • Shipping Time Frame

    We work hard to get all orders placed by 12 pm EST out the door within 24 hours on weekdays because we know how excited you are to receive your order. Weekends and holiday shipping times will vary.

    During busy holidays, we step our efforts to ship all orders as fast as possible, but you may experience an additional 1-2 day delay before your order ships. This may also happen if you change your order during processing.

    View Shipping Times

  • Shipping Restrictions

    It's important to know that due to state and local laws, there are certain restrictions for various products. It's up to you to research and comply with the laws in your state, county, and city. If you live in a state or city where air guns are treated as firearms you may be able to take advantage of our FFL special program.

    U.S. federal law requires that all airsoft guns are sold with a 1/4-inch blaze orange muzzle or an orange flash hider to avoid the guns being mistaken for firearms.

    View Shipping Restrictions

  • Expert Service and Repair

    Get the most out of your equipment when you work with the expert technicians at Pyramyd AIR. With over 25 years of combined experience, we offer a range of comprehensive in-house services tailored to kickstart your next adventure.

    If you're picking up a new air gun, our team can test and tune the equipment before it leaves the warehouse. We can even set up an optic or other equipment so you can get out shooting without the hassle. For bowhunters, our certified master bow technicians provide services such as assembly, optics zeroing, and full equipment setup, which can maximize the potential of your purchase.

    By leveraging our expertise and precision, we ensure that your equipment is finely tuned to meet your specific needs and get you ready for your outdoor pursuits. So look out for our services when shopping for something new, and let our experts help you get the most from your outdoor adventures.

    View Service Info

  • Warranty Info

    Shop and purchase with confidence knowing that all of our air guns (except airsoft) are protected by a minimum 1-year manufacturer's warranty from the date of purchase unless otherwise noted on the product page.

    A warranty is provided by each manufacturer to ensure that your product is free of defect in both materials and workmanship.

    View Warranty Details

  • Exchanges / Refunds

    Didn't get what you wanted or have a problem? We understand that sometimes things aren't right and our team is serious about resolving these issues quickly. We can often help you fix small to medium issues over the phone or email.

    If you need to return an item please read our return policy.

    Learn About Returns

Get FREE shipping on qualifying orders! Any order $150+ with a shipping address in the contiguous US will receive the option for free ground shipping on items sold & shipped by Pyramyd AIR during checkout. Certain restrictions apply.

Free shipping may not be combined with a coupon unless stated otherwise.

View Shipping Info

Text JOIN to 91256 and get $10 OFF Your Next $50+ Order!

* By providing your number above, you agree to receive recurring autodialed marketing text msgs (e.g. cart reminders) to the mobile number used at opt-in from Pyramyd AIR on 91256. Reply with birthday MM/DD/YYYY to verify legal age of 18+ in order to receive texts. Consent is not a condition of purchase. Msg frequency may vary. Msg & data rates may apply. Reply HELP for help and STOP to cancel. See Terms and Conditions & Privacy Policy.