Gas Piston system

[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.