Mossberg 500 Light Primer Strikes

[NapaCountyShooter]

So I've had my Mossberg 500 for 7-8 years or so. It's been great and is my primary HD weapon. Never a problem. I've probably put 5-600 rounds through it over the years. The last 2 times I've been to the range, a disturbing thing has happened. The first round I chamber gives me a light primer strike. I eject the live round, and from then on, it's 100%. This is very disturbing. I haven't taken the bolt apart yet, but it seems to me that it sounds like junk in the firing pin chamber? Maybe the firing pin spring is getting weak? Looking for some opinions. It's been taken off of HD duty until I can figure this out. I'll take it apart this weekend, but some experienced direction would be appreciated. Thanks.

[shellslinger]

Wow that is disturbing. My worst nightmare is that when I pull the trigger and i hear the dead man's click. Any how, my best guess is that your firing pin spring may be getting weak. It seems odd that with only about 5-600 rounds through a time span of 7-8 years the firing pin spring shouldn't be getting weak.

Just seems as if that the firing pin spring prematurely wore out. And like you said, it could also be gunk in front of the pin as well.

[jeffrice6]

Check the firing pin & spring

[eccvets]

how often do you fully strip and clean it?

[BigDogatPlay]

Not sure if the firing pin spring being weak would lead to light strikes. The force of the hammer works against the firing pin spring, not with it, so a weak spring should result in heavy strikes and pierced primers.

Definitely strip the bolt and give everything a good look / cleaning. Clean out the locking recess on the barrel shank as well just for grins. If it persists, visit a gunsmith.

FWIW... my 500 is over 30 years old with several thousand rounds through it. Still on the original springs, still goes bang every time and has never had a stoppage.

[NapaCountyShooter]

Not sure if the firing pin spring being weak would lead to light strikes. The force of the hammer works against the firing pin spring, not with it, so a weak spring should result in heavy strikes and pierced primers.

Definitely strip the bolt and give everything a good look / cleaning. Clean out the locking recess on the barrel shank as well just for grins. If it persists, visit a gunsmith.

FWIW... my 500 is over 30 years old with several thousand rounds through it. Still on the original springs, still goes bang every time and has never had a stoppage.

Yeah, thanks. I'm figuring there's buildup around the firing pin that is slowing it down enough on the first strike that it leads to the light primer strike and that first shot displaces the gunk enough that it's good to go after that, then maybe it re-solidifies for the next session? I'll take apart the bolt today and run some compressed air in there.
Thanks for all the responses so far. Hopefully I can get this resolved. Love the gun otherwise.

[TheKlawMan]

I vote that the trigger assembly needs a good cleaning. If it is gunked up, the first fall of the hammer may be weak but the same firs fall may loosen things up. I wonder what happens if you snap fire one at the range and then fire your first.

[NapaCountyShooter]

how often do you fully strip and clean it?

I'll admit, I've never taken the bolt apart. It's field stripped and cleaned after every range session. I don't shoot it often enough. Hopefully I can resolve this myself. If not, it's off the the smith.

[NapaCountyShooter]

I vote that the trigger assembly needs a good cleaning. If it is gunked up, the first fall of the hammer may be weak but the same firs fall may loosen things up. I wonder what happens if you snap fire one at the range and then fire your first.

That is another possibility. I'm going to give it a good detail strip tonight and we'll see if I can take it out tomorrow or sometime next week to test it again.

[eccvets]

dont skimp on the clp or hoppes/cleaner
dont forget to lube it up, everything likes lube... (well not too much)

[inbox485]

Sounds like a gummed up bolt. Clean it out. And go easy on the lube. Lube attracts crap, and crap slows the action down.