GTA
All Springer/NP/PCP Air Gun Discussion General => European/Asian Air Gun Gates => China/Asian AirGun Gate => Topic started by: bantam5s on March 27, 2018, 04:18:52 PM
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Can a standard B-19 / Crosman Optimus....ect ( I've now got both ) be tuned back to say 600fps ?
If so how easily can it be done ?
I'm not much of a springer guy, but I've got my generic B-19 as well as the Crosman Optimus my brother left me before moving out of state, and wouldn't mind turning one of them into a quieter easier to shoot 15yd plinker.
I liked the Ruger explorer I had bought as a teenager for this , but for various reasons that's out.
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Easiest way is to just cut coils off of the spring. You will want to "clean" the cut end up afterwards. I've even heated the cut end and bent it to make a flatter finished end. Then you will want to polish it so it will spin freely within the piston and on the spring guide. This will remove a ton of twang and torque. A generous amount of heavy tar on the spring will also deaden the vibration and reduce the shock within the spring coils. As for how many coils to remove... it's a trial and error thing. You can take them off but you can't put them back on unless you get a new spring. Might as well do all the other home tuning tricks while in the gun such as, de burring, polishing and lubing.
One other note.... when a spring compresses it also grows in diameter. Any sharp and jagged points may grip surfaces they come in contact with.
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Easiest way is to just cut coils off of the spring. You will want to "clean" the cut end up afterwards. I've even heated the cut end and bent it to make a flatter finished end. Then you will want to polish it so it will spin freely within the piston and on the spring guide. This will remove a ton of twang and torque. A generous amount of heavy tar on the spring will also deaden the vibration and reduce the shock within the spring coils. As for how many coils to remove... it's a trial and error thing. You can take them off but you can't put them back on unless you get a new spring. Might as well do all the other home tuning tricks while in the gun such as, de burring, polishing and lubing.
One other note.... when a spring compresses it also grows in diameter. Any sharp and jagged points may grip surfaces they come in contact with.
Thanks.
I figured I'd have to cut coils off, but figuring out how many will be the hard part since I don't have a chrony to test velocities.
I'll wait and see if someone chimes in who maybe has lowered a B-19 to as low as 600fps.
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I've never lowered a B19's power but I do believe they are over powered for their weight. In addition to Bill's suggestions I recommend sleeving the piston. I like a pop bottle sleeve between the spring and piston. It smooths things out a bit.
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Yeah.. it's really going to depend on the current state of the existing spring. I've seen various length springs in the same model guns depending on where they are in their lifespan.
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Another trick I learned from Mike Mellick is to wrap the spring guide with alternating layers of shrink wrap and heavy tar. That really takes the buzz out and goes a long way to making the shot cycle have that solid "thunk" that all spring gun tuners shoot for.
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A Crosman standard spring is 36 coils. You can either cut about 4 coils off, or leave the back spring guide out of it to reduce preload. I have done both and prefer the latter method, as it reduces the velocity considerably by taking the preload off the spring, and acts like cutting off 4 or 5 springs. And the added benefit of not having to buy another spring if you want to convert it back is there. A good tune is in order when ya do that like Bill said. It's the way I have done it and serves to make a very tame shooting rifle.
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Ok, well this b-19 has maybe had 1000 pellets through it at the most.
It's probably 6 years old and was sold as a firepower FP-1, imported through cybergun I believe and with your typical 1100fps rating.
By all accounts a Standard generic B-19.
I was thinking of just removing enough to take the preload out of the spring and seeing where this gets me, but I don't know how short is too short.
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Like I said, just take out the rear spring guide. It takes the preload wayyyyy down. The rear spring guide is there basically just to add preload anyways. It doesn't guide any thing.
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Like I said, just take out the rear spring guide. It takes the preload wayyyyy down. The rear spring guide is there basically just to add preload anyways. It doesn't guide any thing.
You posted while I was typing.
Thanks for the tip.
I took that guide out, and tested it a few shots.
this may sound like harassy but I'm leaving it at that, it seems to be exactly what I wanted and only took minutes.
I'm not a springer guy, and as far as right now I'm satisfied with it as a plinker.
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Well, there ya go..... next?
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Well, there ya go..... next?
Not sure.
Down the road I may decide to do all of the recommended things, but for now I'll just shoot it.
I'm pretty sure the power is now around 600-650 fps with crosman 7.4's which is where I wanted it.
I just don't care enough about the gun to put money into it, I wanted to make it something I can plinking with every once in a while for a change of pace. I like using just enough power to hit what I'm aiming at consistently, and like to keep it quiet.
I love my pumpers, but can't deny the fun of cock load and shoot of a springer.
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Down the road I may decide to do all of the recommended things, but for now I'll just shoot it.
I'm pretty sure the power is now around 600-650 fps with crosman 7.4's which is where I wanted it.
...but can't deny the fun of cock load and shoot of a springer.
Before I changed its spring, my Airhawk had gotten down to shooting in the mid 500's.
It was so sweet, so gentle, so much fun to shoot.
The spring was just worn (out? In?) but not broken. I saved it in case I want to swap it back in some day, because I really think I want to swap it back in some day ;)
Blue
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Down the road I may decide to do all of the recommended things, but for now I'll just shoot it.
I'm pretty sure the power is now around 600-650 fps with crosman 7.4's which is where I wanted it.
...but can't deny the fun of cock load and shoot of a springer.
Before I changed its spring, my Airhawk had gotten down to shooting in the mid 500's.
It was so sweet, so gentle, so much fun to shoot.
The spring was just worn (out? In?) but not broken. I saved it in case I want to swap it back in some day, because I really think I want to swap it back in some day ;)
Blue
I've got the spring from an old broken airhawk that I could shorten and put in for my dad.
He hardly shoots any of his guns and this pretty hard to cock black airhawk has probably only had 50 shots through it in the past 5 years. It's so harsh shooting that the wood stock was uncomfortable against your cheek when firing, so we put the broken Blackhawks synthetic stock on it
If I shorten it enough where the spring only has about 1/16 of preload ( so its not loose to move back and forth like my B-19 now is ) he may injoy and shoot it more.
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you could just call crosman and order a spring or a ram set from a crosman F4 ILLINOIS model which were listed at 695 fps. that should be a straight swap and while you are there, clean it, and then tar it. it should be right at low 6s with mid weights and 6s with heavies, as well as the sweetest springer you have ever shot short of a R7...
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you could just call crosman and order a spring or a ram set from a crosman F4 ILLINOIS model which were listed at 695 fps. that should be a straight swap and while you are there, clean it, and then tar it. it should be right at low 6s with mid weights and 6s with heavies, as well as the sweetest springer you have ever shot short of a R7...
That's a good idea for a springer guy.
I'm not though and am not willing to put any money into it, it's good enough for me for now.
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David,
Just curious how quiet the report is on the de-tuned B-19. Is it any quieter than the 880 ? I was kicking around getting a lower powered springer for an ultra friendly backyard gun and I,m thinking a de-tuned Optimus might do the trick.
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David,
Just curious how quiet the report is on the de-tuned B-19. Is it any quieter than the 880 ? I was kicking around getting a lower powered springer for an ultra friendly backyard gun and I,m thinking a de-tuned Optimus might do the trick.
XS-12 from Mike at Flying Dragon. I suggest it in .177. Either way, under $100. You won't find a better guy to deal with. If you want to spend a little more, go for the full tune or ask him about de-tuning an XS-25.
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Have a crosman G1 extreme I got from flea market for $15...shooting around mid 7's and when i decided to replace the spring it was like 1 3/8" shorter than the new oem spring. Got the seal replaced and got it to low 9's....I got power but not shooting as smooth as before and it doesn't like CPL 7.9. I put back the old spring and all's well until 4 or 5 tins later I got 2 springs in front of the spring guide.
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Bill, I should have bought the XS12 a few months ago when you suggested it. I just posted on the Crosman gate about switching my Vantage NP to a springer to build a detuned easy shooting gun.I figured that I would try and turn the Vantage into something that I would like and also help with the tinkering itch I now have after tuning the Hatsan.
The Vantage just cocks too dang hard for my worn out shoulder and elbow.For some reason it,s even noticeably harder than the Benji NP that I gave to my brother.
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Posted elsewhere.
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Have a crosman G1 extreme I got from flea market for $15...shooting around mid 7's and when i decided to replace the spring it was like 1 3/8" shorter than the new oem spring. Got the seal replaced and got it to low 9's....I got power but not shooting as smooth as before and it doesn't like CPL 7.9. I put back the old spring and all's well until 4 or 5 tins later I got 2 springs in front of the spring guide.
I have a G1 Extreme as well, that I bought used. I was surprised that it was easy & accurate for me to shoot , since I am not a Twanger guy. I tested it & it is shooting a little over 700, but pretty smooth. I found a Crosman Vantage , like new, & it shoots 900 fps. It really is a TWANGER & is hard to shoot. I had rather have the G1 any day ! I wonder if they have the same spring & the G1 is just weak.
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David,
Just curious how quiet the report is on the de-tuned B-19. Is it any quieter than the 880 ? I was kicking around getting a lower powered springer for an ultra friendly backyard gun and I,m thinking a de-tuned Optimus might do the trick.
From what I can hear my 880 on 3-4 pumps is still a good bit quieter than the B19, granted it's not exactly fully tuned and there are things that could reduce the noise.
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it is very quiet. the fact that it is undersprung and that it has so much more mass than a little rifle... they are quiet...
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David,
A pumper will always be quitter then a Springer. Just as a PCP will be. You don't have the long spring rattling around!
The suggestion to remove the rear spring guide is fine to reduce preload but I'd suggest a custom guide in delrin.
What that does is reduce that twangy sound in springers and you don't need tars!
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Yeah Dave, there are things you can do to it, with out spending any money to quiet it down. I sleeved the piston on mine with an old pop bottle plastic sheet, and polished the spring ends, and made a plastic bushing out of a pop bottle for the bottom of the spring, and used a tungstun disulfide lube..... Made a big difference with out having to pump money into a AG you just want to shoot occasionally.
You could have cut a spring or bought a new spring and cut it or bought a custom set up for it, or just removed the rear spring guide which really doesn't so anything other than provide pre load on that platform. From what I gather though it is doing what you wanted for about a few minutes work and zero cash. Enjoy bro, :).
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Yeah Dave, there are things you can do to it, with out spending any money to quiet it down. I sleeved the piston on mine with an old pop bottle plastic sheet, and polished the spring ends, and made a plastic bushing out of a pop bottle for the bottom of the spring, and used a tungstun disulfide lube..... Made a big difference with out having to pump money into a AG you just want to shoot occasionally.
You could have cut a spring or bought a new spring and cut it or bought a custom set up for it, or just removed the rear spring guide which really doesn't so anything other than provide pre load on that platform. From what I gather though it is doing what you wanted for about a few minutes work and zero cash. Enjoy bro, :).
I may try some of these things in the future.
A project is a project, so anything free I can do I'll probably do at some point just for something to do.