Got a new to me Kimber 84 montana .243 and have found the factory ammo it like best, Remington 80 grn cor-loc bullets. Thing is, with that brand ammo I get failure to fire about every 3-4 shots. A google search suggests this is a fairly common firing pin spring problem and a wolf spring would be an excellent replacement. Does this sound about right? I mean, with this ammo I get 3 shots touching at 100 yards, so I hate to give up on the gun. But if I can't trust it to go off every time I pull the trigger, then it is no good to me.

So a new spring and a trip[ to the gun smith sound about right?

Not necessarily. The tension on the firing pin spring is adjustable. There is a set screw that locks the firing pin in place and if the set screw comes loose, the pin can rotate and lessen the spring tension. It happened on one of my 84M and I was getting some misfires from weak pin strike. Try increasing the spring tension and using some locktite on the set screw.

Tag

Is there gas cutting on the bolt face? Carbon can build up between the firing pin stop and the back side of the bolt face. Taking the firing pin out and looking at it should give you some idea. check the inside of the bolt body for carbon, too.

And Checking with a no-go gauge might very well show a sloppy long chamber. Kimber is notorious for them. Reloading can fix that, but if you are willing to shoot CoreLokt factory ammo...

That screw is for firing pin protrusion and not tension. While it may work that is generally not the root of the problem. Order a replacement higher energy spring from Wolff springs and the problem will be solved. I have had to replace around 20 of the factory springs with the Wolff ones and have had no further issues. They can be purchased directly from Wolff.

Here is the part number- 65840 KIMBER 84 BLITZ STRIKER SPRING 40 LB 8.29

This isn’t an argument, but it is an honest question, because I can’t find the answer.

Why is this bolt designed to adjust pin protrusion? Why is this necessary?
In order to adjust for pin protrusion, the firing pin travel has to be stopped by the cocking piece hitting the bolt body. If I adjust the firing pin to max protrusion, the pin travel will be stopped when the firing pin shoulder bottoms out on the inside of the bolt body. My current two 84M’s have a max protrusion of approx .055” once the pin shoulder is stopping the travel. I can increase the tension on the spring by adjusting a little more.
The remington 7/700 I’ve owned seem to have a fixed pin protrusion of .052” - .055” and they bottom out on the firing pin shoulder.

Mechanically it makes sense to me to have a fixed pin protrusion, but be able to adjust tension on the spring to deal with variations in spring tensions. It seems like it would be easier to manufacture firing pins to a tight tolerance to meet a fixed protrusion, and there doesn’t seem to be a concern for adjusting for firing pin wear.
I would think the springs would be harder to hold a tight tolerance and they can weaken with age and use.

Does Kimber recommend a different protrusion measurement based on cartridge?

I always check firing pin protrusion on all new-to-me Kimber’s, then if correct (.050), I’ll apply several coats of nail polish to “lock” the screw in place.



To check/adjust firing pin protrusion (from an old post by big whoop):

1. Verify an empty chamber and put on safe.
2. Move the safety to position #2.
3. Remove bolt. The firing pin is cocked and NOT protruding from the bolt.
4. Hold the bolt in your left hand (so you can see the 3 digit s/n looking up at you on the handle) and rotate the cocking piece with your right hand COUNTERCLOCKWISE. It will lock into the next position. Now push the safety into the "fire" position. The firing pin will snap forward and now the pin will be protruding from the bolt hole. You can measure it, photo it or make a mental pic of it. It should be barely protruding based on your earlier primer photos.
5. Now is when you can loosen the locking set screw with a 1/16th hexhead - just a couple of turns. Now, using a properly fitting slotted screwdriver you can turn the screw CLOCKWISE and watch the pin protrude further. I think 1/2-3/4 will do it. You can photo it or measure it although I don't know what you would use to measure it.
Re-tighten set screw.
6. Now you have to manually cock the firing pin. Hold the bolt again in the left hand and turn the cocking piece CLOCKWISE til it snaps into the small cutout on the rear of the bolt. It'll take a some force.
7. Put the bolt back in the action and check your function and safety positions.
8. The next range session or primed empties will check your work.

I went through the same exact thing.I contacted Kimber and they sent me a new spring under warranty even though the rifle is about 10 or so years old (308 Montana) the new spring was approximately 3/4-1”” longer I managed to get it all back together with my limited Gunsmithing skills and everything now working correctly

OK guys! Thanks for the education!! This something I can do my self? Sounds like maybe so...

Yes

TAG

I had some issues with light primer strikes with my 308 when it was new. Adjusting the firing pin protrusion solved my problems. I experimented with brass with just primers in them at home to get every thing adjusted right.

Yes, Brad, I remember a couple of those rifles. Talk about getting a bad case of the "flinches"!! IIRC that was when Kimber CS would talk to you as an adult.

Tag

I had some FTF with two different Kimbers. After a little research I switched from CCI primers to Federal. No problems since.

My latest Montana build was giving me misfire problems even with the firing pin protrusion set properly. I tried ordering a new spring from Wolff but they’re not shipping Internationally during this pandemic.
So I made a small bushing to put a little more squeeze on the trigger. I shortened the bushing a little more after taking the picture. I’ll eventually replace the spring when I can get one, but for now it’s working great.

https://imgur.com/a/n7CWPl7

Bringing this thread back up

Had a failure to fire this past weekend, thankfully it was only on a doe and not a trophy of any sorts (Montana 280 ackley). Rifle is probably 10 years old, been on a few hunts but hasn't been shot a whole lot.

Just contacted Kimber - "NOPE - We don't know anything about this and there is no replacement". Was their response I know there's the WOLF spring, which I guess I'll go that route. I did adjust the pin with the directions provided, but it's a little upsetting. Have to other Kimbers I need to check as well, while I'm at it.

Anyone else have any luck dealing with Kimber, or just did the adjustment or went with the aftermarket spring? I read on another forum that the aftermarket springs, don't always fit as they're to large in diameter.

Thanks for any feedback.

I was having this problem last year with a CRF M77 Hawkeye. After getting several duds I noticed the firing pin force seemed somewhat diminished from when the rifle was new. A new Wolff spring with increased rate fixed it right up.

Tag…

Have had a number of issues with Kimber CS and their "Gunsmiths" including an obviously out of spec chamber. They were worse than useless even after two return trips. One to the old address and one to the new Alabama site. Neither fixed the obvious problem. Their system is an absolute joke.

Sorry to read this is still a problem that shows up. With so few rifles being made, this doesn't bode well for the future home in Alabama. Pretty rudimentary QC at the factory - the buyer shouldn't have to deal with this. Brad has the "fix" spelled out above.

You can tighten that protrusion adjustment TOO much as well..... I was having the same issues, I ordered the wolf spring and it was too large diameter to fit so I called Kimber and finally talked them into sending me a new firing pin/spring combo. The new firing pin was the exact same dimensions as the old one but the new spring was quite a bit longer. I installed it and thought I had it fixed until 5-10 rounds later and got the dreaded "click" again. Not sure when it dawned on me or if I read it somewhere, but I finally thought.... if I have that screw tightened down too much it will actually slow the spring down in its travel ..... I backed it off until I was certain that it was just barely touching the shoulder stop inside the body and now have had probably 100 rounds with no issue. I think it needs that full travel to build up the speed/inertia to hit that primer hard enough? Who knows lol.

TAG

tag

Bringing this back to the top. I just ordered the spring from wolf. Anyone have any tips for changing it out when it arrives? I've changed the spring on military Mausers. Same principle?

TAG