How could Vince's gun backfired when Gabe used it before he did?
It's shown in the reveal at the end of the movie that Vince takes a clip from Rafe's gun (the guy who was beheaded) suggesting that it was the rounds that were tampered with rather than the gun itself.
That is right. ... Thanks for the insight. :-)
He used the gun as a hammer to get out of the morgue.________________________This signature has been deleted by the poster