Model 12 getting light hits on primer

model 12 getting light hits on primer unless I close the gun very hard, harder then I feel comforable doing . Firing pin was replaced recently . Any thoughts ? Sugestions? Thanks Tom

 

May be some wear on the lock groove on the top inside of the receiver. Also check your headspace and you might need to rotate headspace ring outward a turn.

 

The first suggestion is the worst case scenario.

 

I can't wait to see where this goes...

 

What was the reason for the recent firing pin replacement?

 

The firing pin was'nt smooth , that was replaced about 5 000 rounds ago. In the picture was from the last box I shot . On the left is a good hit the two on the right didn't fire

 

What make of primer?

 

Looks to me like #1 is the real problem. I'd call Mark Lonczynski at 570-455-6091. He's my go-to guy on Model 12's.

 

Wow, those primers look deep. Maybe it's just the picture.

 

Primer is at correct depth and they are Noble sport

 

Take your trigger out and look it over. I had one that the trigger fell apart when I disassembled
it. Replaced broken part and it shot fine. Good luck.

 

You might look at the hammer spring. I had a similar problem, when I removed the spring and compared it to a new one the problem was obvious.
Tim

 

Someone I know that is more than very knowledgeable about Model 12's explained the purpose and function of the Model 12 chamber ring. If worn, which it s designed to do, the shell will move too far forward in chamber which can result in misfires. A chamber gauge, actually a set, is what is needed to determine the possible wear. The set includes "go, no go, and almost won't go gauges. Replacement, including the chamber ring part, is about $200 as I recall.

Another comment he made to me was to NEVER use steel based hulls. The guns weren't made to accommodate the steel bases and will cause extraordinary wear to the chamber ring.

 

Check the gun for bolt droop. To do this, dry fire the gun, rack the action and then raise the carrier with your fingers and press on the bottom of the bolt. Is there excessive movement at the back of the bolt where it engages the locking recess in the receiver? If there is enough movement, this can cause excessive headspace and lead to light primer strikes. Excessive bolt droop can also cause the firing pin retractor to not be depressed enough to allow the firing pin to move forward.

The cure for this is to weld up the tab on the action bar that engages the bolt (or have a new action bar installed). This tab is what lifts the back of the bolt into the locking recess in the receiver. As the back of the bolt moves up, the face of the bolt moves closer to the rim cut in the chamber ring. In this scenario, can excessive headspace be fixed with a new chamber ring? Yes, it can, but all you are doing is moving the rim cut further back toward the face of a bolt that isn’t sitting far enough into the locking recess. By doing this, you’ll eventually beat out the back of the receiver.

I’m not saying that chamber rings don’t crack and need to be replaced, because they do. But I’d like to have a dollar for every Model 12 chamber ring that has been replaced over the years that didn’t need to be replaced. And, for God’s sake, don’t try to screw the chamber ring out a turn.

 

Something knows something about Model 12's.

 

While searching the web I came across a Wolff extra strong hammer spring I ordered it from Mid West and received it quickly, and installed it this morning and in the afternoon I shot 2 rounds of trap and had no misfires . So I hope tahts it . Thanks trying to help . Tom

 

Have you had anymore misfires or light primer strikes?

 

No , But I only had 6 rounds so far , I switch to my 870 every other month then back to the MD 12. thanks for the intereast . Tom