View Full Version : Mossberg 500 malf question

chris in va
June 30, 2008, 11:09 PM
If I'm getting light primer strikes, what part of the trigger group needs replacing?

I called (edited!) Mossberg and they basically told me to just send the whole thing in. Unfortunately I don't have $60 knocking around and would rather just replace a $3 part myself if that's what it takes.

BTW the firing pin spring on this thing is uber strong. I can't even press the firing pin with a screwdriver...

June 30, 2008, 11:13 PM
Why does Ruger want to see a Mossberg 500?

3 gun
July 1, 2008, 01:13 AM
If you have a Mossberg 500 it's a simple matter to replace the hammer spring. Don't know what to say about Ruger firing pins.

July 1, 2008, 01:27 PM
Try a good cleaning first with a good spray cleaner. Mine had the same problem and a cleaning with powder blaster and light oil did the trick.

chris in va
July 1, 2008, 10:21 PM
Ha ha...sorry guys, I've got too many gun names floating around in this head of mine.


I did hit it with Powder Blaster, didn't seem to change anything. The strikes are pretty shallow when I checked the fired shells. But I'll try again, maybe I just need to hose it down a lot more.

Scattergun Bob
July 2, 2008, 12:37 AM
Have you removed the bolt and checked that your firing pin is not broken. This sometimes causes this malfunction. Check closely, sometimes the crack is hidden by the firing pin spring.

The other common issue is that the locking lug is not allowing the bolt to travel all the way into battery. Please check the locking lug recess in the top of the receiver to make sure it is clean.

Good Luck & Be Safe

July 2, 2008, 03:22 AM
Is the barrel screwed in tight?

July 2, 2008, 06:52 AM
Have you tried different ammo? You could have shells with hard primers.

July 2, 2008, 09:05 AM
I had such a problem. I disassembled the bolt, cut a coil off the firing pin return spring. The spring was too strong to allow the firing pin to move forward with enough strength to ignite the primer. Might be a good idea to replace the hammer spring if the above doesn't work.

As a side note, Remington shells have extremely hard primers. Athey generally require more punch than other ammo to ignite.

chris in va
July 9, 2008, 02:33 AM
The spring was too strong to allow the firing pin to move forward with enough strength to ignite the primer.

That seems to be the case here too. Any particular reason why the pin spring should be so #$%@ stiff?

July 9, 2008, 08:15 AM
Maybe you have a different Mossberg 500 model than me... Mine has NO firing pin spring what so ever....
Here There is a cantilever inside the bolt that resets it when you rack it to reload a round. If that canti is seized.... Don't know nothin' about the trigger group as folks say not to tear into it.