Mossberg MVP light firing pin strikes (known problem)

[Deplorable Me]

I'm trying to help a friend solve an ammo-gun problem.

With factory general purpose .223 ammo the Mossberg MVP shoots reliably.

When 5.56 or semi-auto type ammo is used there are light primer strikes indicative of hardened primers. Ammo fails to go boom. If I run it through my Ruger bolt varmint .223; it goes boom. Good primer hits.

Is there an after market spring available that qualifies as an extra power firing pin spring?

I've hit up a couple of other forums, they can identify the problem but haven't come up with a workable solution.

 

[kev74]

Call Wolf. They probably make an extra power spring.

I would also check how far the firing pin protrudes from the bolt face. Too short is no bueno.

First thing though, if not done already, is to strip and clean the bolt.

 

[GOYABEAN]

There's a improved firing pin just can't remember what company makes them old timers