Swiss K31 trigger problems?

[swheeler]

My Swiss K31 has been having something funny going on with the trigger the last two outings. The two stage trigger will work as it should then the next shot first stage will fire with barely touching the trigger, I'm guessing under one pound of pull, I don't like it one bit. I've owned it since 2005 and when I bought it was torn down and cleaned. First time this happened was about a month ago at near freezing temps. I came home and stripped the bolt, scrubbed it clean with brake cleaner and solvent, greased it well and put it back together. I then checked trigger pull weight, broke relatively consistent and clean at 64 oz for about 5-6 times, then it happened again, fired on start of first stage and didn't even see the scale on gauge move(tells me the sear had barely engaged the cocking piece- so trigger problem). I removed the stock and sprayed the trigger group out with brake cleaner, it was filthy gummed up with what I figure was dried out solvent, Hoppes #9, and 3 or 4 kernels of a stick powder. I put it back together and gave it a dozen dry fire runs, perfect I had fixed it so probably should not be any oil used on that trigger. Now fast forward to last Sunday, on shot number 15 it happened again, I do not like a trigger that isn't the same every shot, scares me! I just got through full cleaning routine again with bolt and trigger, this time looking over sear engagement surfaces with magnifier and light, nothing I can see wrong. I sprayed the trigger assembly with Amsoil MP, put it back together and as usual the second stage trips at a clean 64 oz, same as it does bone dry. I removed the bolt and look into rear of the receiver, the sear retracts approximately 50% of travel with first stage of pull, trigger always fully resets forward bolt in or out, cocking piece looks to have a measured engagement of .050". Anybody else have something like this going on with the K31, any help would be appreciated, my daughters and wife shoot this rifle but no longer until I have this figured out.

[725]

Going to follow this one. Hope you find a cause.

[swheeler]

I do too! I'll be searching the interweb tonight looking for answers.

[Texas by God]

Do any of your friends have one to compare with?

[swheeler]

No I haven't seen a K31 at the range in forever, if ever? I am finding lots of stuff on the internet though about this same problem, but people are telling the guy someone tried to do a bubba trigger job and hacked it in other words they are guessing. I bought this 14 years ago come June, haven't shot it much but from records 1500- 2000 rds and a month ago was first problem, so something wore out or changed. I will keep reading, someone has to have figured this out. While looking for parts I can find some but haven't found a cocking piece for sale yet, maybe that is the fix and they are all gone. From 725's post I'm guessing he has one or one with the same problem?

[Tackleberry41]

Guess I do not shoot mine enough to develop the issue.

[swheeler]

I have found several posts where people claim changing the mainspring fixed the problem, the rest say cocking piece was the problem. I have found a couple complete bolts, they cost almost twice what I paid for the gun. I'll keep reading, there's plenty of them with this problem.

[swheeler]

I just ordered a new replacement main spring from RSI, can't hurt after 72 years of service by the original one. No luck locating a cocking piece yet, or cocking key as many are calling it. It does look like an old key though!

[725]

No problems yet. Just want to recognize it if it comes along.

[Texas by God]

K-30 ones have a special place in my heart because that's the only iron sight rifle I have ever fired a 1-inch group at a hundred yards with. It made me mad that I couldn't match the Surplus Ammo accuracy with my reloads! Good luck in getting it lined out.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[swheeler]

Yes this rifle is plenty accurate for me, love it. I put an S/K scout mount and AIM scope on it. Everything serialized is matching including stock and handguard, it was the cleanest one by far, of the 5 delivered except it was the only Beech stock, they were all supposed to be walnut, so 89.00 to me. The toe had been repaired and stock had 80% of the orange shellac on it, issue tag under the butt plate. It has the import stamp from CAI near the muzzle. All the Walnut stocked ones looked like they had been dragged behind a horse over ten miles of bad road. I still have the 50 284 Winchester brass that I used to shoot it before I got some Grafs brass. I want this handed down to the kids or grandkids but want it to be right before I go!

[swheeler]

I got the RSI replacement main spring in Saturdays mail, put it in the bolt tonight, now to find some trigger time.

[samari46]

Blame the Swiss soldiers who stuck the butt stocks in the snow and probably their hob nailed boots had also something to do with it. Gunboards had some pics with the butt stocks stuck in the snow. Frank

[Tackleberry41]

Its just age, Swiss soldier took way better care of their weapons. Unlike our military where you get issued a weapon, but spends most of its time in the armory, give you a different one on a whim. Swiss took theirs home, so were responsible for their long term care. Most surplus is rode hard and put away wet. Swiss rifles even really old ones are still in good condition. Parts wear out, just problem with Swiss rifles is they are not easy to replace.

[swheeler]

Yes parts are hard to find for the Swiss beauties. Rock Solid has some neat after market parts for them like 10 round magazine, new firing pin, and mainspring.

[truckjohn]

Sounds like something is stuck and the trigger isn't fully returning. I would carefully check all the parts for binding or burrs.

[HollowPoint]

When you pull the bolt back to extract and eject the empty brass, do you pull it all the way back or just far enough for the base of the brass to hit the ejector to eject the shell? I ask because I can't picture in my mind how it would be your main spring that's causing this. I'm not saying that it isn't the source of your trigger problems, it just seems to me that if it is one of the springs it might very well be that hair-pin shaped spring in the trigger group itself. Perhaps that little spring has undergone some metal fatigue after all these years.

Back when I was experimenting with my K31 re-barreling and re-locating the position of my bolt knob I found the parts I was looking for on Ebay. I didn't actually find the exact parts listed but the parts I did find lead me to the seller so I contacted him and asked if he had the bolt-shroud or the bolt handle for sale. He said he did but he just hadn't listed them cause he didn't think anyone would buy them. With springs like those pictured above my reply, it's not that hard to make your own. Even the hair-pin spring I mentioned can be made at home if you know the diameter of the wire used.

If you find parts listed on Ebay, try contacting the seller and asking if they got what you need. For example; NO EBAY LINKS, EVER. Please

This is a listing for an entire K31 bolt assembly for only sixty-two bucks and free shipping. Someone selling this must surely have other parts of that same rifle for sale. Contact them to find out. The worst that could happen is that they'll say no, they don't have the parts. $62.00 bucks for an entire bolt assembly is like taking candy from a baby.

HollowPoint

[swheeler]

HollowPoint thanks for the link and info, I'll check it out later today. I thought the same thing about the mainspring affecting the trigger, I found several posts where people claim that was the fix for this problem so for 15 dollars thought I would give it a try. To answer your question about ejecting cases, from the bench I move the bolt back just enough to collect the case in my hand, and this is the position I first noticed the trigger problem, and since we have a good snow cover that would have been how it happened last time also firing offhand, I wouldn't eject the brass into the snow, but I actually do not remember if I did. I was looking more for a sear engagement issue caused by that goofy looking cocking piece, rear half of the firing pin, skeleton key what ever it is, cocking piece to me?? The trigger resets to forward position and fires from there, extremely light, scares the bejesus out of me, get cross hairs lined up and touch your finger to the trigger whamo. The pull is so light I don't think I could measure it with my TP gauge, I'm scared to have anyone around it until I know it works properly. I have found several posts where the problem was fixed by swapping out the cocking piece, aka cocking key, but I know about internet solutions not always being the fix? My first thought was dirty trigger group especially after finding powder kernels in there, must have been 7383 from long ago. You think maybe limp wristed, girly ejection of spent brass could be the culprit? Thanks for replying to this, still searching for the answer.

[swheeler]

6 bids at 62.00, couple days left, not bad the last I looked at was 157.00 buy it now IIRC

[swheeler]

I just found 2 cocking pieces for K31, bought one for 30.00. I will save it until I get to put 50 or so rounds through the rifle with it's new main spring to see if that was the "fix", if not I will put the original spring back in and try the cocking piece I just bought.