Primer strike after releasing slide?

[strakill]

OP, a little trick we use in the shop is to take a spent casing or a snap cap and place a piece of masking tape over the primer and rear of the case. Drop it in the chamber, let the slide slam home and slowly eject the case and inspect the tape. Also you could rack the casing out quickly and see if you're hitting the ejector.

[tomk556]

I also vote for the ejector or previously light-struck round, and I agree the firing pin block shouldn't permit a slam fire, or any contact from the firing pin. As others have said, it also doesn't look like a glock firing pin strike.

[86 5.0L]

[strakill]

A lot of handguns slide will slam home if the mag is shoved in hard enough. Nothing wrong with it IMHO. I actually prefer that. All my Glocks do that, my CZ, M&P, and my old Sig would all do this.

[tomk556]

My Glock 19 goes into battery on it's own when I'm spirited with reloads, perhaps one in four times. I'd say it's a sign you're properly handling the weapon. You'd have to youtube it or talk to a knowledgeable armorer, about where the firing pin block is throughout a full firing cycle, but I believe it should be back in place even as early as when the slide starts it's initial movement to the rear.