Mossderg 500 safety stuck.

[std7mag]

My future son in law asked me to look at his Mossberg 500 12ga.
The safety was stuck in the fire position.
Not ever having taken one of these apart before, i told him i'd do what i could.

Disassembly went fine.
Spent many hours (7+?) cleaning and getting unburnt powder (?) out of the receiver.
Gave safety mechanism good dousing of gun scrubber, then WD40.
Safety started moving while shotgun was disassembled.
Cleaned up all the excess WD40 and used a few drops of gun oil.

I then reassembled and performed check. Slide works as advertized, but safety frozen solid in the safe position.

I've taken this thing apart & put back together 5 times now.
Trying to check things each time.
Same results. Safety moves while disassembled. Frozen when assembled.

Any help would be GREATLY APPRECIATED!!

 

[nwmnbowhunter]

If i remember correctly it's just a little screw that holds down the safety switch?

If so we had to slowly tighten them a little at a time. there was a spot that allowed them to move freely and then all of a sudden they would be stuck.

 

[CJ6]

Is the spring and detent ball in good shape? Is there a groove in the thumb pad ? You can get replacements for all of these.

 

[std7mag]

The screw that holds the safety mechanism together is a security screw.
You can tighten it, but not loosen it.
I can cut a slot in the screw to loosen it, but doing so would also cut the exterior safety switch.

I can get it to move fairly freely with the gun disassembled.
But once assembled, it's frozen.

 

[std7mag]

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

 

[CJ6]

Possible... But I'm thinking if you had the gun toredown that maybe the trigger/safety weren't in alignment when put back together. There are diagrams of them by searching Mossberg 500. There's a tab on the trigger assembly that needs to mate with the safety.

 

[Fast14riot]

If the trigger adjustment screw is too far out of adjustment, it will cause the trigger block tab (vertical post on trigger group) to interfere with the safety.

 

[nwmnbowhunter]

We were able to take security screw out by pushing firmly and unscrewing it... not perfect, but it did come out. They make replacement kits on ebay with raised lever on the switch.

 

[nwmnbowhunter]

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

Yes. That was the case with the two we had.