I got a LE 10.5 SBR I have recently modded to run the Osprey Gas Piston kit. Read a lot of good things about it, thought I'd try it. Osprey does recommend running it on minimum of 11.5" barrel but I read quite a few posts in which 10.5" guns worked well with it. Mine is a factory Colt 10.5 LE and after installing the system, I ran several different rounds through the gun. The brass Ultramax 55gr and SS109 ran just fine, threw the brass like 6 feet. Wolf 55gr however, ejected the round but was unable to pick up the next one (short stroking). My rifle has a H buffer and factory Colt m4 spring. Any Ideas on how I can make the rifle run the cheaper Wolf ammo? Maybe a lighter spring of buffer?
Osprey recommend 12.5" barrel as the optimal minimum for SBR. Yeah I also read that people use it on 10.5" barrels working fine. You should try using a standard buffer, if that doesn't work, use a lighter spring. I didn't want to have trouble on mine, so I choose 12.5" barrel and standard buffer and buffer spring.
I called Osprey and they said to try a HEAVIER buffer? He said that steel has a longer "relax" time and that the case is holding on to the chamber longer than the brass, so the heavier buffer may give it slightly more resistance to keep the bolt closed that milisecond longer to allow the cartridge to shrink back down to normal. Does this make sense?
Originally Posted By Vmon:
I called Osprey and they said to try a HEAVIER buffer? He said that steel has a longer "relax" time and that the case is holding on to the chamber longer than the brass, so the heavier buffer may give it slightly more resistance to keep the bolt closed that milisecond longer to allow the cartridge to shrink back down to normal. Does this make sense?
Did he understand you? I mean for what He said your problem should be FTE and you would have some signs of the extractor trying to rip the rim off the cartridge.
But you said SS, that usually means under power ammo (if everything else is ok as you pointed out with all the other ammo).
the guy at osprey believes because the case is prematurely being pulled before it has a chance to contract, all the energy from the bleed off gas is being expeled on trying to pull the steel case out of the chamber. He believes the heavier buffer will give it a bit more time to relax and the gas system will have an easier time extracting it which will leave more energy for the bolt to travel farther back. Not sure if this is correct but thats what he said.
