"Got what I assume is the infamous century arms bent piston the other day"
Huh? First I've heard of it. It only fits back in a certain way...hmmm...have you tried spinning the thing while installed? If so, does is bind periodically? I'd be more inclined to believe a repro-piston has a slightly fat diameter at the journal that fits through the receiver block, making things much tighter and more finicky, or an overall length too long or something to install easily, than it being bent from the factory. I also wonder if it might simply be a needlessly sharp or burred corner at that hole in the receiver, giving you less wiggle room than needed to tilt the piston out. Even for Century, it's a pretty simple part, so I'd be surprised at it being made wrong (and even more at it failing in use, given how short it is.) Why not just buy a Bonesteel Arms or other repro, of same or better quality? You are only saving at most 10$ over a repro.
TCB