A couple months ago, I picked up one of the PSA $59 or $69 BCGs, and it has been sitting on the shelf waiting for a build. Finally got around to finishing the build, and I'm having a slight issue. The upper is a Spike's flat top A3, with Ballistic Advantage 17.7" barrel and GunTec keymod forend on an Anderson lower. I was able to get everything assembled, with no problems...until I dry fire the lower. Anytime the hammer is drop, it takes a decent amount of force to get the carrier moving backwards. Now, its not from the pressure of the hammer spring, it feels more like its having problems unlocking (if that is the correct term). I tried the upper on several different lowers, and had the same problem. As soon as the hammer is back, no issues....carrier slides perfectly. However, as soon as the hammer drops, problems again.
I started looking at the upper, and noticed the carrier looks a little different than others. If you will look in the pic, the portion of the carrier just to the rear of the port door is open....
Of course, this is not what any of my other rifles look like....
I have another BCG I just picked up, its one of PSA's "Premium" groups that recently went on sale. Old carrier on top, Premium on bottom...
May be difficult to see in the pics, but basically the rear firing pin shroud(?) on the carrier on this one has been milled completely to just below the gas key.
Now, I have never seen one milled this way (or at least noticed it) in all the AR's I have owned. Is this a manufacturing defect, or should it be OK? I haven't tried this particular BCG in any other rifles yet, but the Premium BCG works absolutely perfect in the new build.
Any guesses on what's causing the hang-up with the hammer forward?
I have tried this BCG in three different rifles, and still get the same issue (whereas other BCG's continue working fine).