DPMSBANDIT I have to strongly disagree. The AK has far looser clearances, they are over-gassed as built and the carrier/piston assembly has much more mass to force the bolt closed. Grit or lack of lubrication can cause an AR to malfunction to the point the forward bolt assist cant push the bolt forward. The AK design give you the option to push the bolt forward, pull it back or rock it to clear the jam, with a lot more force. The bolt design of the AK just has two lugs VS the multi lug of the AR. if AR bolt locks closed you have very little leverage with the charging handle and have to hope bumping the stock on the ground or wedging a screwdriver up the mag well will free it. In the unlikely event an AK locks shut (never had it happen) you can just whack the charge handle with a rock ECT. I have quite a few AK's and AR's and can attest the AK design wins in the reliability department.
The AK was deigned for an unskilled soldier who wasn't as likely to maintain or understand how his firearm worked. Cost was a huge factor and is pretty much a disposable design.
The DI AR is a far better rifle if given minimal attention and once broken in its very reliable and far more versital.
A piston AR is a solution to a problem that doesn't exist-I would argue that they are less reliable.