M&P shield 9mm light primer strikes

[NorCalGlock9]

I bought a shield 9mm a few weeks ago and took it to the range yesterday. I shot about 200 rounds through it, a couple mags of HST and the rest was the aluminum case federal 115 gr fmj. I had 2 rounds of the aluminum cased ammo that didn't go off. The primer was dimpled so the striker did hit them but didn't go off. I set them aside and shot them later and they worked the second time. Has anyone had similar issues? Either with the shield or the aluminum cased stuff? I've never had this issue with any of my other handguns. Thx

[Varg Vikernes]

Was it just the aluminum cased stuff?

[NorCalGlock9]

Yes, only the aluminum cased ammo

[ojisan]

Aluminum cases are not as slippery as brass, they can stick while feeding, resulting in the round not fully chambering.
When this happens, pulling the trigger, and the hammer or striker then falling, usually will fully seat the round in the chamber.
If you have a gun with second-strike ability, the second trigger pull will usually fire the round.
If you have a gun without second strike, there is no choice but to rack the slide and eject the unfired round.

Aluminum cases are for plinking or target practice only.
Never use aluminum cases for serious uses in an autoloader.

[NorCalGlock9]

That makes sense, I did have to push the slide forward into battery a couple times when I tried to rack a round in. It's strange that this is the only gun this happens with. I have used this ammo in glocks, xd's, Sd9ve, Kahr, etc. with no issues.