Mossberg 500 locked up

[samsmix]

I have a "Western Field 550" aka a Mossberg 3" magnum pump that has a severe problem: when the gun is fired, the action does not unlock. I can open the gun by pressing the slide release, but cannot simply rack the action and continue firing. I know it isnt the ammo, because it happens even when the gun is empty.

Any thoughts on what could be causing this?

 

[Randy_che]

Check for a sticking action release lever.

 

[jaguarxk120]

Now is the time for a really deep cleaning. The trigger group out and cleaned.

After a complete cleaning and the problem is still there then start looking for worn parts.

 

[samsmix]

I've not torn the trigger group apart, but I have hosed it out with carb cleaner and lubed it. Can't see any obvious wear. Has anyone experienced this isuue before?

 

[g.willikers]

There's a couple of springs that are involved in the proper operation of the action lock lever.
Parts 1, 2 & 3:
http://www.brownells.com/schematics/Mossberg-/500A-12-Gauge-sid160.aspx

 

[samsmix]

Thanks g.wilikers. I was discovering that this morning, using my daughter's 20ga trigger group for a reference. I still cannot see the part causing the trouble, but it is clearly the lock lever that is holding it shut, failing to depress when the trigger is pulled.

 

[samsmix]

I had to take a break to go shoot my antelope, but I'm back into this. I cannot see any broken or worn parts. A thorough cleaning has been done. Does anyone have any more clues?