Mossberg 500 safety stuck.

[std7mag]

My future son in law asked me to look at his Mossberg 500 12ga, as the safety was stuck.
Took it home and disassembled.
Spent hours (7) cleaning and getting the unburnt powder (?) out of the receiver.
Soaked the safety with WD40.
Got it to move ok while disassembled.
Lubed with light coat of gun oil.
Assembled.
Everything seems to operate correctly, except when assembled the safety is stuck again.
I've had this freak'n thing apart 5 times now, and always the same.
Disassemble & safety moves.
Assemble & it's stuck.

Any help would be GREATLY APPRECIATED!!

 

[Roughedge]

is the metal safety detent plate installed upside down?

 

[std7mag]

I'm assuming you mean the plate attached to the exterior safety tab?

I have not taken the screw out of the exterior safety tab.
For some unknown reason it looks like a security screw.
You can install with a straight blade, but the sides for loosening are ground so that there is nothing for the screwdriver to bite into.
It looks machined this way, not just rounded off.

If i cut a groove in it to loosen it, i'll end up cutting the safety tab also.

 

[natman]

I have not taken the screw out of the exterior safety tab.
For some unknown reason it looks like a security screw.

It is a security screw. The safety is plastic. It's easy to overtighten the screw and crack the safety and then badmouth Mossberg. They got tired of that, so for better or worse they started fastening the safety with a security screw.

Search YouTube for " mossberg 500 safety screw removal " and there are several videos on how to get the darn thing out. However, it's unlikely that the problem is with the safety mechanism itself.

 

[std7mag]

I was wondering about that, as it moves when the gun is disassembled, but frozen when assembled.

 

[amd6547]

Any stock changes recently? The stock bolt can interfere if screwed in to far.

 

[std7mag]

I had thought about that too.
I asked.
Factory installed synthetic stock.

Could it be something so simple as the safety tab screw being too tight?

 

[Drm50]

I never paid much attention to Mossberg products. I don’t know when they started with the plastic safety button. When I was in business in 70 thru 90s the main problem with 500s was the plastic safety button itself. We set up and milled them out of aircraft aluminum. Sometime in 80s someone was marketing a steel replacement. I don’t know anyone who got a metal safety button that ever had trouble again. The plastic button was gaulding and and jamming/ locking up the safety.

 

[natman]

I had thought about that too.
I asked.
Factory installed synthetic stock.

Could it be something so simple as the safety tab screw being too tight?

Doubtful. If the screw were too tight it would probably bind all the time, not just when assembled.

I'd look for something in the rest of the gun being assembled incorrectly and preventing the safety from moving.

 

[Powermwt]

Look at the safety block...

All I have here is to question FSIL about when he last fired the shotgun and what he did to it after he found out it is not working.

You think you put something back correctly and it won't work that many times .... well, something is not back correctly. I have had other firearms where a spring put on the wrong side of a pin lets you fire once but cannot cycle...