24hourcampfire.com
24hourcampfire.com
Previous Thread
Next Thread
Print Thread
Hop To
Page 1 of 3 1 2 3
Joined: Nov 2007
Posts: 4,899
R
Campfire Tracker
OP Offline
Campfire Tracker
R
Joined: Nov 2007
Posts: 4,899
My question is...how do I adjust the firing pin on a 300 wsm Kimber 8400. I noticed very small pimer dents in primers and had 2 of 10 missfire last time I went to the range. My guess is I have to loossen a set screw near the back bottom of bolt??? and then turn the slotted screw on the back end of the bolt one way or the other. Is this correct and if so please explain so I can verify. thanks For any directions given.

[Linked Image]

Is the Black circle the set screw to loosen first???

[Linked Image]

Then I turn this "slotted" screw one way or the other slightly (if so, how far)

[Linked Image]

I'm assuming the screw down by the locking lugs has nothing to do with adjusting the firing pin...see below

[Linked Image]





BP-B2

Joined: Jan 2003
Posts: 3,367
Campfire Tracker
Online Content
Campfire Tracker
Joined: Jan 2003
Posts: 3,367
Before doing anything, decock the assy. and measure the firing pin protrusion (how far the pin tip protrudes though the bolt face). -Al


Forbidden Zoner
Joined: Nov 2005
Posts: 22,734
B
Campfire Ranger
Offline
Campfire Ranger
B
Joined: Nov 2005
Posts: 22,734
RBH,
The slotted screw in the rear of the bolt is your adjustment. Let me play around on one of my Montana's and get back to you.
I haven't done it in a couple of years.


My home is the "sanctuary residence" for my firearms.
Joined: Nov 2005
Posts: 22,734
B
Campfire Ranger
Offline
Campfire Ranger
B
Joined: Nov 2005
Posts: 22,734
RBH, Ok I got it.
Your black circled set screw is a 1/16th hex head. It holds the slotted screw in check so it can't turn on its own.

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 don't know your aptitude and if you are a bit hesitant to do this, please do not.
I have re-read my text to make sure it makes sense. I have also done this to my 8400 Montana(300WSM) and 84M Montana(.308) and it works with both action sizes.
Ask me any questions here if I don't make sense. As you can see the firing pin assembly never gets unscrewed from the bolt.

Good luck and keep us posted.


My home is the "sanctuary residence" for my firearms.
Joined: Nov 2007
Posts: 4,899
R
Campfire Tracker
OP Offline
Campfire Tracker
R
Joined: Nov 2007
Posts: 4,899
Originally Posted by Al_Nyhus
Before doing anything, decock the assy. and measure the firing pin protrusion (how far the pin tip protrudes though the bolt face). -Al


How do I do that???

IC B2

Joined: Nov 2007
Posts: 4,899
R
Campfire Tracker
OP Offline
Campfire Tracker
R
Joined: Nov 2007
Posts: 4,899
Originally Posted by bigwhoop
RBH, Ok I got it.
Your black circled set screw is a 1/16th hex head. It holds the slotted screw in check so it can't turn on its own.

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 don't know your aptitude and if you are a bit hesitant to do this, please do not.
I have re-read my text to make sure it makes sense. I have also done this to my 8400 Montana(300WSM) and 84M Montana(.308) and it works with both action sizes.
Ask me any questions here if I don't make sense. As you can see the firing pin assembly never gets unscrewed from the bolt.

Good luck and keep us posted.


BW, is the safety in position #2 where it sticks straight out rather than all the way back or forward???

Joined: Nov 2007
Posts: 4,899
R
Campfire Tracker
OP Offline
Campfire Tracker
R
Joined: Nov 2007
Posts: 4,899
BW, what is the "cocking Piece",.... The bolt handle???

And... If i could measure the protrusion of the firing pin, how far should it protrude from the bolt face???

Joined: Nov 2005
Posts: 22,734
B
Campfire Ranger
Offline
Campfire Ranger
B
Joined: Nov 2005
Posts: 22,734
RBH.
Position #2 (in Kimber Manual) is what you described - the safety sticking straight out. Or, its the position you have to use to unscrew the firing pin assembly from the bolt inorder to clean or inspect for grease or oil buildup.

Keep us posted.


Last edited by bigwhoop; 10/09/10.

My home is the "sanctuary residence" for my firearms.
Joined: Aug 2010
Posts: 28
H
Campfire Greenhorn
Offline
Campfire Greenhorn
H
Joined: Aug 2010
Posts: 28
It's not a visual measurement, firing pin protrusion is measured with a firing pin protrusion gauge and should be .055" - .065". See Brownells for the gauge.

Joined: Nov 2005
Posts: 22,734
B
Campfire Ranger
Offline
Campfire Ranger
B
Joined: Nov 2005
Posts: 22,734
RBH,
Here you go, another bit of advice.There is a tool for measuring pin protrusion. Although you could set it up on a dial caliper and compare the two.


My home is the "sanctuary residence" for my firearms.
IC B3

Joined: Nov 2007
Posts: 4,899
R
Campfire Tracker
OP Offline
Campfire Tracker
R
Joined: Nov 2007
Posts: 4,899
It seems no matter what I do, the firing pin is the same or less. I measured it as best I could with my calliper using a point low on the bolt as a base and it seems it sticks up about .025-.030. Adjusted the firing pin by screwing it in a little and a lot but no significant difference. In fact, I screwed it in a couple of full turns and it barely dented a primer. I mean it barely left a mark, much less a dent. Then I backed it out to near where I thought it should be (just less than flush with the back of the bolt) and 50% of the rounds fired. What should I do at this point, give it to a smith or send it to kimber???

Joined: Jan 2003
Posts: 3,367
Campfire Tracker
Online Content
Campfire Tracker
Joined: Jan 2003
Posts: 3,367
You need to have around .050-.055 protrusion for consistent ignition with all primers. Take it to a competent 'smith (note the word 'competent') and have it adjusted correctly.

I'd not return it to Kimber. This seems to be a very common issue with their rifles (not enough protrussion). If they don't know enough to set it correctly before it goes out the door, I wouldn't trust it to come back set correctly.

I know of several ho-hum shooting Kimbers that have been turned around just by addressing this issue. Just because the primer will go off doesn't mean the gun will shoot up to it's potential.

Hope this helps. -Al


Forbidden Zoner
Joined: Nov 2005
Posts: 22,734
B
Campfire Ranger
Offline
Campfire Ranger
B
Joined: Nov 2005
Posts: 22,734
RBH,
Sorry to hear that the "fix" didn't work. I would say that the chamber has excessive headspace and the firing pin is pushing the cartridge forward while trying to ignite the primer.
I guess I would call "them" or discuss it with a local smith.
The barrel may have to be turned down a bit to eliminate the headspace. A competent smith would have the tools to confirm this.


My home is the "sanctuary residence" for my firearms.
Joined: Nov 2005
Posts: 22,734
B
Campfire Ranger
Offline
Campfire Ranger
B
Joined: Nov 2005
Posts: 22,734
RBH,
Lets back up a minute and review.
1. Are you the original owner of this rifle?
2. Is this a used rifle?
3. Has this been occurring from the start?
4. If not, how many rounds have you fired?
5. Have you shot any factory rounds and had the misfires?

Lets some idea as to what was going on pre.....misfires.
Thanks.


My home is the "sanctuary residence" for my firearms.
Joined: Nov 2005
Posts: 1,935
D
djb Offline
Campfire Regular
Offline
Campfire Regular
D
Joined: Nov 2005
Posts: 1,935
Is it just me or does there appear to be cratering on the '06 on the left and the 300WSM in question?



The truth angers those whom it does not convince
Joined: Aug 2010
Posts: 28
H
Campfire Greenhorn
Offline
Campfire Greenhorn
H
Joined: Aug 2010
Posts: 28
djb, It's not just you.

Joined: Nov 2005
Posts: 1,935
D
djb Offline
Campfire Regular
Offline
Campfire Regular
D
Joined: Nov 2005
Posts: 1,935
Cool.

I have a Model 70 with an oversized firing pin hole. I am still deciding whether it needs "fixed". It craters with everything hot or cold. Stronger spring and polished firing pin tip helped but didn't cure.

Apologies to the OP for being off topic.


The truth angers those whom it does not convince
Joined: Nov 2007
Posts: 4,899
R
Campfire Tracker
OP Offline
Campfire Tracker
R
Joined: Nov 2007
Posts: 4,899
Originally Posted by bigwhoop
RBH,
Lets back up a minute and review.
1. Are you the original owner of this rifle?
2. Is this a used rifle?
3. Has this been occurring from the start?
4. If not, how many rounds have you fired?
5. Have you shot any factory rounds and had the misfires?

Lets some idea as to what was going on pre.....misfires.
Thanks.

1.-I am the original owner
2. It is a rifle about 4 years old with about 200 rounds thru it.
3. This is the first time I've ever had the problem
4. I've probly shot no more than a dozen factory round thru it since I bought it new several years ago.

Joined: Nov 2007
Posts: 4,899
R
Campfire Tracker
OP Offline
Campfire Tracker
R
Joined: Nov 2007
Posts: 4,899
are you sure you screw the rear screw "in" further to increase firing pin projection. When I screwed it in, I couldn't notice any increase in firing pin length, though it may be I just didn't percieve it getting longer.

Joined: Nov 2007
Posts: 4,899
R
Campfire Tracker
OP Offline
Campfire Tracker
R
Joined: Nov 2007
Posts: 4,899
Originally Posted by bigwhoop
RBH,
Sorry to hear that the "fix" didn't work. I would say that the chamber has excessive headspace and the firing pin is pushing the cartridge forward while trying to ignite the primer.
I guess I would call "them" or discuss it with a local smith.
The barrel may have to be turned down a bit to eliminate the headspace. A competent smith would have the tools to confirm this.


I really don't think it's a headspace problem. I am pretty meticulous about resizing my brass and only set the shoulder back 1-2 thousanths.

Page 1 of 3 1 2 3

Moderated by  RickBin 

Link Copied to Clipboard
YB23

Who's Online Now
674 members (1Akshooter, 1beaver_shooter, 10gaugemag, 17CalFan, 12344mag, 76 invisible), 2,929 guests, and 1,426 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums81
Topics1,187,672
Posts18,399,514
Members73,817
Most Online11,491
Jul 7th, 2023


 







Fish & Game Departments | Solunar Tables | Mission Statement | Privacy Policy | Contact Us | DMCA
Hunting | Fishing | Camping | Backpacking | Reloading | Campfire Forums | Gear Shop
Copyright © 2000-2024 24hourcampfire.com, Inc. All Rights Reserved.
Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.3.33 Page Time: 0.115s Queries: 15 (0.004s) Memory: 0.8992 MB (Peak: 1.0523 MB) Data Comp: Zlib Server Time: 2024-03-28 20:43:49 UTC
Valid HTML 5 and Valid CSS