Does a conventional ACP bullet damage a LW barrel?
Hi everybody.
Finnaly, my shoebox has arrived and I’ll start experiences with 300 bar of Haelium. All prepared to work with 7500psi, so, I’m confident about security.
I ask if a common .25ACP bullet can be used in our LW barrels, or maybe the barrel should be damaged?
I’ve taken notice there are some .25 ACP bullets with a thin cover, so, they don’t damage the barrel.
Does anybody know and experienced?
Gustavo.
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Viewing 13 replies - 1 through 13 (of 13 total)
Naw…it’s just for fun. 😆
Like he says “I’m retired and my wife says brain dead, keep that in mind.
”
😆
if that is his meaning?
Not true IMHO, Helium is a gas, with molecules that are much smaller than the molecules that make up our atmosphere.
A pump designed to compress Helium must have much small cylinder to piston clearances than the Shoebox compressor has. Most of the Helium would by pass the cylinder and piston and be lost, Ie not compressing.
Research compressor design and you will se and better understand what I am saying.
Just to prove my point, Monday I will get a tank of Helium and test the issue. We’ll see who is correct.
is that even a question?
A jacketed bullet would probably leak a lot through the rifling grooves if you could even chamber it. You don’t normally see choked barrels in the firearm world because jacketed bullets tend not to like them. Take that with a pinch of salt as it as only what I read and I don’t know the exact reason why but I do know you never really see them except in shotguns, rimfires, and airguns.
Bullets generally make bad pellets and after a google search I see .25acp fire at similar velocities but much tighter twist rate (1:12 typical) so you’ll have to fire that well into supersonic to stabilize it the same as from a .25acp pistol. The nose shape will give you bad wave drag(at the tip) when it goes transonic and above. It’s an uphill battle at every step and since there’s the risk of damaging your barrel I can’t give the idea my blessing.
In my experience using helium to power paintball guns they make a lot of noise and get no velocity.
Piston to cylinder clearance is not an issue because the orings do the sealing. It’s true helium is harder to seal but it should work good enough to get some pressure up.
Tom Kaye
if that is his meaning?
Not true IMHO, Helium is a gas, with molecules that are much smaller than the molecules that make up our atmosphere.
A pump designed to compress Helium must have much small cylinder to piston clearances than the Shoebox compressor has. Most of the Helium would by pass the cylinder and piston and be lost, Ie not compressing.
Research compressor design and you will se and better understand what I am saying.
Just to prove my point, Monday I will get a tank of Helium and test the issue. We’ll see who is correct.
now for questions for you
what kind of rifle/system are you planning to use ?
what bottle do you have that has 7500 psi working pressure
are you planning to use a valve system like AF rifles ?
AS always is a pleasure to be in the forum….
the system is a condor, with a breech of steel, a 100gr hammer and still the same spring.
The bottle is a 110ci bottle HPA working at 4500psi. I have several regulators and no regulator at all. I can connect the condor to a remote. I will send some photos….
The valve is a modified blodnob valve, can work at 300 bar.
And of course, all this modifications is to fun 😆 😮 😆
Thanks for all the shared wisdom.
Gustavo.
Inquiring minds want to know!
I don’t think you’ll ever find the answer. Takes more energy than a 3000psi bottle can deliver, to inscribe the rifling into a jacket. trust me, been there. So the answer is no, because you can’t get the bullets to exit the barrels.
aloha,
walt
1 i dont see why you would want to go super sonic with an airgun….get a powderburner, unless your in a country where its too problematic to get a rifle the legal way (i dont know argentina…but i do know denmark and i understand the hassle it can be to obtain a gun permit, so super tuning an airgun would be a fun project)
2 7500 psi is quite a bit, make sure your not using the plastic breech of the airforce rifle, it will likely explode…aluminium would be good….keep the breech as light as possible
3 copper FMJ requires a shitload of pressure to engrave….powderburners generate around 15000 psi initially for the low power stuff..you could shoot copper washed bullets (the ones that has microscopic layer of copper) if you fear leading….allthough it should not be a problem…if you can find pure lead projectiles you should be fine…i would go for the softest alloy you can get your hands on….if that leads up the barrel, then shift to a harder alloy
4 you can get 42 grain EJ pellets…with these you can reach substacial power and still stay subsonic….and not need helium….theres also the jerry slugs which would give you even heavier ammo….for increased power, but without using helium
5 helium leaks….making a valve that flows more air is more feasible
6 if your doing this for the fun of it…it sounds like a very fun project
7 here in the US you can buy barrel blanks in just about what ever caliper without needing a permit….this would be the easiest way of getting a barrel made from an alloy that can handle the wear and tear of FMJ
8 some airgun barrels are made from an alloy too soft for FMJ ammo…and the rifling will wear…which barrels can handle it and wich cannot i cant tell you….but call lothar walter and ask them, they should know…they are easy to call here in the US at least….you can use skype(program for pc) to make the call cheaply….crosman .25 barrels are made by green mountain (they primarely make barrels for powder burners) but crosman barrels have been cheap to optain for their regular barrels so maybe this goes for their top notch .25 barrels too
9 seating the bullet could engrave the bullet so making a seating/loading tool that will engrave the bullet as you load it could remove much of the wear on the barrel…just a thought….if your using fingers to seat it, i think it will be impossible….but there are a new type of airgun barrel….it only has rifling on the last 2″ …the rest is smoothbore….this would make a real nice tight seal….and allow the bullit to get up to speed…and then just before it leaves the barrel the rifling grips it and puts a spin to it….this system is used in FX rifles, and have been very succesful…..making such a barrel from a .25 LW barrel doesnt sound that hard to do…but requires you to sand the rifling away manually with a pushrod and sandpaper….its a project right ?….could be worth experimenting with
now for questions for you
what kind of rifle/system are you planning to use ?
what bottle do you have that has 7500 psi working pressure
are you planning to use a valve system like AF rifles ?
it sounds like a very interesting project….and look forward to hear how it progresses….be carefull….if you thought 200 bar is dangerous…well 300 bare would be nearly twice as dangerous….
i would suggest you move up from .25 caliper to .308 or 9mm….hunterssupply.com has a lot of ammo in this caliper meant for highpower airrifles…..
ohh and while im at it….dont use bullets with grease …its sucks…alot of the ammo comes with grease in the grease groove….dump them into a bucket of paintthinner, that will dissolve the grease easily….just rinse with water and ammo is good to go….you could use a super thin layer of pellet oil…but dont use grease, moly or teflon…it all tend to gunk up the barrel and gives you no advantage
good luck
Thank all guys!.
The idea is to put a bullet without any problem in my .25 LW rifle, without forcing the barrel. If I cannot find a bullet like this, ok.
The idea is I’m confident to reach supersonic velocities and a pure lead bullet will not work.
Asking for the matter of the shoebox and haelium.
I have a scuba tank charged at 160bar of Haelium, and a regulator.
I fix the regulator delivery at 85 psi connected to the shoebox instead of the first compressor.
the shoebox starts to pump Haelium to a 110ci 4500psi paintball tank , and That’s it!!
So, I need a bullet that can acces without any problem to my .25 LW barrel and can reach supersonic velocities without any problem in grouping.
Ive never heard of anyone having any success with jacketed bullets in an air rifle. The friction is too great to overcome (or something like that).
I have a question for you though. How are you going to use your shoebox with helium? The shoebox will only compress air as far as I know.
Shoebox could be used to compress any gas fed to it regulated at 100psi
if that is his meaning?
The jacketed bullet question surfaces every year or so….. 🙂
You can buy a mold and pour your own bullets. There is a mold designed for the 25ACP.
Ive never heard of anyone having any success with jacketed bullets in an air rifle. The friction is too great to overcome (or something like that).
I have a question for you though. How are you going to use your shoebox with helium? The shoebox will only compress air as far as I know.
I don’t know if you will do any actual damage due to copper/steel rubbing (I think you’re asking that) but you may have an issue with fit and engraving during the shot cycle. I would not shoot any suspect ACP ammo unless you’ve been able to push it down the bore by hand. Even with 300bar, you’re not going to see the power that a pb produces at ignition.
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Voltar, have you tried to compress helium?
Gustavo.