Mossberg 500 light primer strike issues?

[Double T]

I was gifted a mossy 500 combo for Christmas 2 or 3 years ago. My first shotgun. I've taken several quail and rabbit with it. Never a hang up, until Sunday. I went to shoot at a rabbit and "click", quickly rack the shell out and get ready. The beagle ran the rabbit back to me in about 5 minutes "click", racked and bang. I hit thumper in the leg and it hobbled off to be finished by my stepdad.

Fast forward to woods number two. "Click" bang.

After checking the ammo, I recycled them into the gun and all went bang on the second primer strike. It's federal game #6 shot. Never an issue with this ammo before.

Many question is this, how often do I need to disassemble the bolt completely, and is this a common issue with a gunned up firing pin, or am I missing something. I've got the thing stripped and getting a good soaking in CLP right now. Going to strip the bolt down once I buy a small enough punch, just wondering if this is a common occurrence.

Did my oil gum up? I've been out in far colder temps running the exact same lube with zero issues. Is my firing pin broken? Asking for hints as to what to look for. When I get it apart, I aim to figure this out. I refuse to have a gun that's going to cause me to potentially let game get away. Thanks. TT

 

[halfmileharry]

A good cleaning isn't going to hurt a bit.
ONE box of shells could be a batch of hard primers.
Before panicking I'd try some different shells in it. It doesn't happen often but you could have gotten some bad ones. I'm an old fart and TWICE in my life and a lot of lead down range, I've had bad ammo.
Dirt may be the culprit or gummed up lube. I run my firing pins and channels dry.

 

[singlesix]

I'd vote ammo. I've used pump guns to shoot Trap, 5K rounds per year, and it didn't need more than a swipe down. Never had to take the bolt apart.