The carriers aren't supposed to be snug, just not too loose. Its rare that you get orings that are too big on the inside diameter. Usually the small carrier with no lines and no dots will make any oring tight enough. Hopefully the new orings work for you.
Originally Posted by redarmy27
While you are waiting, check your sear. Make sure it isn't worn at the tip. That could cause the bolt to sit farther forward, exposing the vent hole a bit causing a consistent leak out the front.
As for the piston assembly, you will have to get a new one of those if you want to run a level 10 bolt on an older classic mag. The older mags worked around 350psi and vented air a bit higher than that for safety. The level 10 bolts often work above 450psi.
Except for the Automag in front, its usually the man behind the equipment that counts.