Thread: First AR reccomendations

If you want a piston AR then go for it, but don't get fooled into thinking they're better than DI ARs in every way. It's easy to buy into the 'shits where it eats', 'spews in its own mouth' bullshit (that everyone who doesn't own an AR uses as an excuse for not having one), because it sounds logical that more fouling in the action wouldn't be conducive to reliability. While it isn't, it doesn't cause sporadic unreliability and random malfunctions. The gun will work reliably up until the point that fouling causes to much friction for the action to cycle and the gun will stop (this happens on any auto regardless of operation). For an un-lubed, bone dry M4 it's about 2500 rounds (Test here:The Big M4 Myth: “Fouling caused by the direct impingement gas system makes the M4/M4A1 Carbine unreliable.” | Defense Review). The gun in the test worked 100% reliably up until 2450 rounds. At that point all that was needed to get it working again was lube on the BCG. The same thing will happen on a piston gun it'll just take longer.

The gas that pushes the piston rearward also pushes the gasblock forward with the same force. This produces torque on the barrel while the bullet is still in it, causing potential accuracy loss. On a DI everything happens behind the barrel and in line with it, allowing the barrel to still be essentially free floating and free from forces caused by cycling.

On a DI, gas needs to travel the length of the gas tube before pressurizing the BCG and initiating unlocking of the bolt. On a piston AR, gas starts applying pressure to the piston as soon as the bullet passes the gas port. This causes the bolt to unlock sooner and while there is more barrel pressure pushing the bolt back against the barrel extension. More friction during unlocking = more wear. Extraction also starts while there is more chamber pressure forcing the case against the walls of the chamber, increasing the chance of the extractor slipping off the rim of the case. On a DI, unlocking is not only delayed slightly, but the gas pressure that's pushing the carrier to the rear also pushes the bolt forward relieving some pressure on the bolt during unlocking.

The 416 apparently has a very high cyclic rate 950RPM or something, which allows less time for the extractor, ejector, mag and bolt stop to do their jobs.

So if you want an AR that costs more, is less accurate and wears down its expensive proprietary parts faster, all because you can’t be bothered applying a small amount of lube to your BCG every few thousand rounds, then a piston AR is for you.

Get whatever makes you happy, if that’s a 416 then go for it. Just don’t think that you need one because people who don’t have ARs have given you the ‘shits where it eats’ speech. I used to think I needed one for that reason.