I got a PSA colt fed lower that took a bit of tweaking to get to run reliably. Seemed I had more issues than the guys I see running their Glock lowers. I had to mod ejector a bit and definitely work down that hybrid bolts hard edges, used quarters to adjust timing a bit and slow down the bolt as well. After THAT she runs great; suppressed and unsuppressed with subsonic 147s. Don't ever seem to hear those stories from the D/S Glock PSA lowers, may be that I haven't been around to hear though