Sometimes My Montana Doesn't Go Bang

[Blockcaver]

Stronger spring fixed my Montana 7mm08 right up...serial number 18thousand ish. Kimber never fixed it when I sent it in. Gunsmith fixed it in 15 minutes while I waited using spring stock he had in his drawer of springs. He checked the firing pin protrusion and it was in spec. Mine was the second Montana he changed springs on that week! Turns out the other was also a 7mm08 with a serial number within 10 of mine!

Cocking effort was minimal with the bad spring. Now it cocks harder as it should, same as my other two Montana’s that never had FTF issues. Bet anything the spring fixes your issue. Good luck!

 

[WCB]

I would just not mess with it and call Kimber and get it done "right".

 

[eaglemountainman]

I just got off the phone with Kimber. They're sending out a new spring for $7.50.

 

[Wrench]

I like .050" as a minimum. The spring may well be the issue. It's important to start at the start with these because there are several things that can cause the issue.

After measuring pin protrusion I'd check chamber. This could be done with a gauge if you have it, or take a sized case and place 2 to 3 layers of scotch tape on the case head. With the safety in the middle position, the bolt should not close on 3 layers, 2 should be tough and I'd be happy if 1 caused resistance.

This is a low down cheap and easy way to see if the case is being held by the extractor when it fires, or the headspace.

If protrusion and headspace are on, bolt body / firing pin friction and spring are the last suspects.

It only takes a few minutes to test all of the possibilities....but they should be done systematically to avoid masking other problems.

 

[eaglemountainman]

Apologies for not following through. The replacement spring did the trick.
Last year I had the same condition develop with my other Montana. A new spring also remedied that situation.