@@surge45-70 Well, both DI and pistons are gas driven with a gas block, but they're both different systems that have different implications when firing in water.
@@deanc91 it is said, that water in a DI Gas Tube will cause issues with the bolt / carrier since it is uncomrpessable and thus puts the whole system far out of spec. In several tests you can see, how bad real AR-15 (Di) react to be fired under water. So this test here is actually surprisingly. On short stroke piston you don't have any issues with water locked systems. But well, how often does one shoot submerged or with in fractions of seconds after emerging from water. So for me, AR-15 only with original Stoner system.
