Gas Piston system

[Lowell Higley]

I have a 6.5 Grendel on a AR platform. Has any one installed the Piston system on the AR Platform. My research has found four different makers and they are all different.

[Double Naught Spy]

I have Superlative Arms systems running on two of mine. Very happy with how they work.

[shooter545]

I have Superlative Arms systems running on two of mine. Very happy with how they work.

+1 on SA. We used one on a friend of mine's rifle and it runs like a sewing machine.

[tashley680]

I have an Osprey Defense unit on my 18" Grendel upper. It hasn't gotten many rounds through it as yet, but I've had good service from these units on other caliber uppers (5.56, 7.62x39 and 5.45x39)

[CJW]

Why are you boys running pistons? What’s wrong with regular gas system?

[VASCAR2]

Piston driven gas systems tend to run cleaner if using a suppressor.

[Klem]

Piston driven gas systems tend to run cleaner if using a suppressor.

That's not my experience using an Adams Arms unfortunately - When using a suppressor with piston, cases and receiver end up just as filthy as a DI system. Suppressor soot comes from the chamber, not just the gas tube. The added back pressure when using a suppressor means as soon as the case unseals the gas flows back around the case into the receiver. Same spit in the face for left-handers, same dirty unfired rounds at the top of the mag.

Went back to using an adjustable DI system for just that reason. What's the point of having a heavy, chunky gas block if it does nothing more than a DI system. Plus I was limited with using a handguard that is only as long as the block.

[montana]

That's not my experience using an Adams Arms unfortunately - When using their suppressor, cases and receiver end up just as filthy as a DI system. Suppressor soot comes from the chamber, not just the gas tube. The added back pressure when using a suppressor means as soon as the case unseals the gas flows back around the case into the receiver. Same spit in the face for left-handers, same dirty unfired rounds at the top of the mag.

Went back to using an adjustable DI system for just that reason. What's the point of having a heavy, chunky gas block if it does nothing more than a DI system. Plus I was limited with using a handguard that is only as long as the block.

Same here. More recoil impulse, more weight and less accuracy with my piston conversions. Once the adj gas block appeared on the scene, I went back to the DI and never looked back.

[Double Naught Spy]

Piston systems vent outside of the chamber instead of through the chamber, hence they should run cleaner, but it isn't a huge amount. SA allows you to change the pressure with and adjustable gas block that works two ways and you can choose which you prefer. You can reduce the speed of the piston (hence, the BCG) by venting pressure or by cutting off pressure. Pretty nifty.

Recoil pulse is reduce by the correct adjustment of the gas block.

I run a heavy barrel and often get sub MOA groups from ammo using a thermal scope (not the most precise of crosshairs). I can't say that a piston system is making my gun any more inaccurate.

Without gas rings on the bolt, no fouling their of consequence to deal with that will influence the operation of the gun, which is nice.

[montana]

Piston systems vent outside of the chamber instead of through the chamber, hence they should run cleaner, but it isn't a huge amount. SA allows you to change the pressure with and adjustable gas block that works two ways and you can choose which you prefer. You can reduce the speed of the piston (hence, the BCG) by venting pressure or by cutting off pressure. Pretty nifty.

Recoil pulse is reduce by the correct adjustment of the gas block.

I run a heavy barrel and often get sub MOA groups from ammo using a thermal scope (not the most precise of crosshairs). I can't say that a piston system is making my gun any more inaccurate.

Without gas rings on the bolt, no fouling their of consequence to deal with that will influence the operation of the gun, which is nice.

As a side note, the DI AR system has proven more reliable in mud test, "as the venting gases blows foreign material away from the open ejection port" unlike the AR conversion piston system. Not a game changer, but a reality. Fouling has never been a problem with my DI rifles and if lubed properly, will run longer than any possible amount of ammo you could possibly carry.. The AR DI is actually an internal piston and not a true DI, "which collects carbon like any outside piston system" but in a different place. My rifles did not group as well with the piston conversions, the recoil was much more pronounce and add unneeded weight This is why I have never seen an AR piston rifle used in competition. My piston rifles ran reliably, but the excessive recoil, weight and degradation in accuracy proved more trouble than any perceived gain. The piston conversion system I used, "was self regulating" and was the reason I used them in the first place. With the advent of adjustable gas blocks, I dropped all of them. The correct balance of the recoil system, gas adjustment, barrel "weight" and muzzle break is something to experience to appreciate. The lubricity between the BCG and AR upper receiver, trigger impact friction, and the quality of the bolt carrier and buffer tube are just a few important factors when balancing a system. Light weight BCG's, "did not have the impact I originally thought they would have on recoil" and now collect dust on my shelf because of it.. I use BCM, M-16, micro slicked BCG's and will compare the low recoil of my AR rifles to anyone's LMBCG. The great thing about the AR rifle system, "is the way we can build a rifle to fit our own needs" instead of being restricted to a one fits all choice.

[CJW]

Great post Montana.

[Double Naught Spy]

No doubt if you have excessive recoil, something is wrong with your system, notably how it was set up. Sounds like the self-regulating wasn't regulating properly.

[montana]

No doubt if you have excessive recoil, something is wrong with your system, notably how it was set up. Sounds like the self-regulating wasn't regulating properly.

The first 18" Alexander Arms barrel I purchased was over gassed and would not function. The piston conversion I installed was an Adam Arms and it ran flawlessly. They are self regulating if proper gas is available. I have tried other piston conversions throughout the years and I even have a Rhino conversion from the 80's. The carbine length piston conversions recoil less than the mid length piston conversions. I had the luxury to test piston set ups with the same barrels through out the years and do side by side comparisons. The recoil on any piston gun conversion is different than a DI. Record your split times or do a side by side comparison. When I use the term excessive recoil, I'm talking split times. Many people like their piston conversions and more power to them. I on the other hand have a shelf full of piston conversions collecting dust.

[HighDesertDrifter]

A buddy of mine has decided to build a 12.5 with a pof piston system. will report back when we've shot it a bit.