I have two big AR Grendels. One with an Alexander Arms Overwatch upper, the other a home built using an identical 24" Shaw barrel, along with an Adams Arms Piston and bolt carrier. My homebuilt has a Daniel Defense free floated rail type handguard vs the tubular free floated guard on the Overwatch. My range only goes out to 250 yards and I honestly do not see any discernable difference in accuracy. The piston unit is a little heavier, but considering they are both big bench or prone type guns it is insignificant. The piston unit is so much cleaner that it's hard to believe it is an AR. I have three other guns with piston units, two are mid length with AA pistons, on in 5.56 the other 6.5 Grendel, all identical except for barrel and bolt, the other a 5.56 with an Osprey piston( so I could use a standard AR front sight) All have performed flawlessly and are a snap to clean. Again I cannot see any accuracy differences among these guns compared to di types at the ranges I shoot, and really wonder about either system affecting accuracy. With the gas port so close to the muzzle I wonder if the bullet has not already left the barrel before the gas can overcome the piston and bolt/bolt carrier inertia or the gas can travel down the tube and do the same in the di system.
I have not researched history on the two systems, but as far as I know in the US weapons the piston was in much earlier widespread use, the M1, and later M 14. Maybe the di was a solution to simplify and reduce cost and number of parts required , and possibly some weight. Someone else can probably give better answers to this than I.
I have not researched history on the two systems, but as far as I know in the US weapons the piston was in much earlier widespread use, the M1, and later M 14. Maybe the di was a solution to simplify and reduce cost and number of parts required , and possibly some weight. Someone else can probably give better answers to this than I.
Member before 2010, account deleted per 2011 spam attack