UPDATE .... Tried my ideas, their ideas, and ideas from y'all. Nothing worked. RMA'd and they turned it around the same week. Got it back with a brand new end-cap and with anti-seize on it to avoid this next time. I've got seven (7) SilencerCo suppressors, and every time I've ever had an issue, they ALWAYS do the right thing, and never charge me a cent ... even when the problem is my fault (like when I didn't seat the suppressor correctly and "shot it off" my 300-WM). Anyway ... stuck end-cap problem solved. I'm an un-compensated SilencerCo fan-boy !!!