K-31 trigger problem

hodaka · July 2, 2006, 08:17 PM

Hello, one of my favorite things about the K31 and the 1889 SR that I have are the triggers. Very smooth and crisp double action. Lately, the K31 has been going off when I don't want it to. The first stage takes up, then boom. It only happens about one shot in 10 but it really ruins groups. I have cleaned it with carb cleaner so the mechanism was dry and it does it, then I lubed it with gunslick and it does the same thing. Have any of you experienced this problem? Is the sear worn? Is there anything I can do, or part to replace? Thanks.

Toolman · July 2, 2006, 08:28 PM

I have two of the K-31's and have never had any trigger problems. You might check this site, it may have info to help. You can also download the english verson manual for your K-31. It's 83 pages and very detailed.
www.swissrifles.com

Harry Bonar · July 2, 2006, 08:51 PM

Dear Shooter:
These are excellent rifles! Make sure your guard screws are tight.
I would think that on your first stage of that excellent two-stage trigger is going too far and giving very little sear contact on the final stage. This is symptomatic of someone having to mess with the trigger to get a lighter pull. However, it could be a number of things. You could disassemble it and see how much sear you have left after the first stage ends. Also you can see if a pin is loose - just check that sear out! It might be binding on the wood.
I doubt very much if it left the Swiss like that for they are meticulous workmen!
This is very, very symptomatic of people with limited mechanical savy fiddling with a trigger to get it lighter! Such are accidents waiting to happen.
Getting a trigger lighter is what they think will stop them from flinching, or, to make flinching less!
I still state that a proper breaking 4# trigger is sufficient for all shooters.
If your trigger or bolt look funny you can order a new trigger from Gun Parts.com.
I had a Hakim 8X57JS that was full auto! The way the trigger group is set up the guard screws weren't tight and upon tightening them it was AOK!
The SMLE rifle had the trigger mounted in the trigger guard and could suffer the same problem - Your K31 is not mounted in the trigger guard. After the No4, Mk** the trigger was frame mounted.
I would guess a pin is loose, or someone has fooled with the trigger!
My K31 has about a 4# trigger - good and crisp.
Hope you find out.
Harry B.
P.S. Lest anyone think I fired it full auto Oh! No! I found the problen prior to buying the rifle and corrected it before firing - I don't want an MG42 out of it!

hodaka · July 2, 2006, 09:21 PM

Thanks Harry. I'll pull it back apart this week and look it over closely. I bought the rifle from Samco,( or was it Sarco??) the importer and have never done anything to the trigger other than the previously mentioned cleaning and lubing.

hodaka · July 4, 2006, 04:31 PM

For the record, I decided to have a go at disassembling the trigger. Piece of cake. I did two things and I'm not sure which one worked, but so far so good. Careful examination of the surfaces of the sear, and the piece on the bolt to which it faces, showed irregular surfaces. Using a small flat file, I smoothed them. Just a couple of short strokes on each. I then used Mil-tec on the pivot points of the mechanism. Everything is working very smoothly now and the trigger seems consistent. I shot two boxes this morning and it worked as it should. The K-31 trigger is a very clever design that disassembles easily. I would put a new spring in it if I could find one.

July 2, 2006, 08:17 PM	#1
hodaka Senior Member Join Date: April 23, 2006 Location: South Texas Posts: 2,010	K-31 trigger problem Hello, one of my favorite things about the K31 and the 1889 SR that I have are the triggers. Very smooth and crisp double action. Lately, the K31 has been going off when I don't want it to. The first stage takes up, then boom. It only happens about one shot in 10 but it really ruins groups. I have cleaned it with carb cleaner so the mechanism was dry and it does it, then I lubed it with gunslick and it does the same thing. Have any of you experienced this problem? Is the sear worn? Is there anything I can do, or part to replace? Thanks.

July 2, 2006, 08:51 PM	#3
Harry Bonar Senior Member Join Date: December 5, 2004 Location: In the Vincent, Ohio general area. Posts: 1,804	K31 Dear Shooter: These are excellent rifles! Make sure your guard screws are tight. I would think that on your first stage of that excellent two-stage trigger is going too far and giving very little sear contact on the final stage. This is symptomatic of someone having to mess with the trigger to get a lighter pull. However, it could be a number of things. You could disassemble it and see how much sear you have left after the first stage ends. Also you can see if a pin is loose - just check that sear out! It might be binding on the wood. I doubt very much if it left the Swiss like that for they are meticulous workmen! This is very, very symptomatic of people with limited mechanical savy fiddling with a trigger to get it lighter! Such are accidents waiting to happen. Getting a trigger lighter is what they think will stop them from flinching, or, to make flinching less! I still state that a proper breaking 4# trigger is sufficient for all shooters. If your trigger or bolt look funny you can order a new trigger from Gun Parts.com. I had a Hakim 8X57JS that was full auto! The way the trigger group is set up the guard screws weren't tight and upon tightening them it was AOK! The SMLE rifle had the trigger mounted in the trigger guard and could suffer the same problem - Your K31 is not mounted in the trigger guard. After the No4, Mk** the trigger was frame mounted. I would guess a pin is loose, or someone has fooled with the trigger! My K31 has about a 4# trigger - good and crisp. Hope you find out. Harry B. P.S. Lest anyone think I fired it full auto Oh! No! I found the problen prior to buying the rifle and corrected it before firing - I don't want an MG42 out of it!

July 4, 2006, 04:31 PM	#5
hodaka Senior Member Join Date: April 23, 2006 Location: South Texas Posts: 2,010	I think I fixed it For the record, I decided to have a go at disassembling the trigger. Piece of cake. I did two things and I'm not sure which one worked, but so far so good. Careful examination of the surfaces of the sear, and the piece on the bolt to which it faces, showed irregular surfaces. Using a small flat file, I smoothed them. Just a couple of short strokes on each. I then used Mil-tec on the pivot points of the mechanism. Everything is working very smoothly now and the trigger seems consistent. I shot two boxes this morning and it worked as it should. The K-31 trigger is a very clever design that disassembles easily. I would put a new spring in it if I could find one.

July 2, 2006, 08:28 PM	#2
Toolman Senior Member Join Date: April 7, 2006 Posts: 514	I have two of the K-31's and have never had any trigger problems. You might check this site, it may have info to help. You can also download the english verson manual for your K-31. It's 83 pages and very detailed. www.swissrifles.com

July 2, 2006, 09:21 PM	#4
hodaka Senior Member Join Date: April 23, 2006 Location: South Texas Posts: 2,010	Thanks Harry. I'll pull it back apart this week and look it over closely. I bought the rifle from Samco,( or was it Sarco??) the importer and have never done anything to the trigger other than the previously mentioned cleaning and lubing.