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SKS Carbines => Unaltered SKS Rifles => Chinese SKS (Military) => Topic started by: Tvchance on November 06, 2017, 04:09:00 PM

Title: Trigger Job
Post by: Tvchance on November 06, 2017, 04:09:00 PM
Okay, first, I understand the SKS was never designed to be a "tack-driver," but I always felt like mine could have a better trigger. Mine displayed a "negative" sear engagement (Which I guess is typical of the SKS), resulting in a very long creep of the trigger pull. Seriously, mine almost felt like a lighter double-action trigger pull. Before going to work on my sear, I measured the trigger pull and was very surprised to find it weighed 4 pounds, 11 oz. (I was expecting it to be much heavier). I changed the face of the sear, where it meets the hammer, for a "positive" engagement.  The resulting trigger pull is heavier than what it was (Which I did expect) but it looks like I've eliminated virtually all of the creep and the trigger breaks clean with no perceptible over-travel. While I like the overall trigger pull much better, I have increased the pull weight to 9 pounds. I'm sure I can reduce this weight by reducing the angle I've put on the sear. I know that sounds like a heavy trigger pull (And it most certainly is) but getting rid of the creep and drag has made it a much cleaner trigger. I'll continue to tweek on it.
Title: Re: Trigger Job
Post by: Power Surge on November 06, 2017, 06:24:32 PM
The more positive the sear angle, the heavier the trigger pull will be.

The SKS gets away with negative sear angle, because the pull is so long, and the surface area on the sear is very large.

When you shorten the sear to shorten the pull length of the trigger, you definitely want to take all the negative angle out of the sear. At the LEAST, make it neutral. If you have negative sear and a really short pull, you're seriously risking the gun going off if it takes a good hit, like being dropped or falling off your bench.
Title: Re: Trigger Job
Post by: Tvchance on November 06, 2017, 10:24:41 PM
Right. I knew I would make the pull heavier but I think I've made the angle for the positive engagement a little too steep. I'll continue to tweek that angle to lower the pull weight but maintain the positive engagement. So far, I'm pretty pleased with my progress.
Title: Re: Trigger Job
Post by: Phosphorus32 on November 07, 2017, 12:44:16 PM
Well you're certainly braver than I am. If I ever had the urge to mess with one of my SKS triggers...I'd stop  doh1  :)) ...and send it to Power Surge or Kivaari  :)
Title: Re: Trigger Job
Post by: Tvchance on November 07, 2017, 03:38:13 PM
Well you're certainly braver than I am. If I ever had the urge to mess with one of my SKS triggers...I'd stop  doh1  :)) ...and send it to Power Surge or Kivaari  :)
Well, I'm looking at this as an opportunity to learn a new skill.
Title: Re: Trigger Job
Post by: Tvchance on November 07, 2017, 03:40:02 PM
Well you're certainly braver than I am. If I ever had the urge to mess with one of my SKS triggers...I'd stop  doh1  :)) ...and send it to Power Surge or Kivaari  :)
And on that note, I ordered a new sear today. LOL!  rofl2 Oh, well... I'm sure I'll get it>
Title: Re: Trigger Job
Post by: Loose}{Cannon on November 08, 2017, 03:42:11 PM
Not 'alot' of tweeking can be done on a sear.
Title: Re: Trigger Job
Post by: Tvchance on December 06, 2017, 01:18:21 PM
Not 'alot' of tweeking can be done on a sear.
Ha! Yeah, I learned that the hard way. I've replaced the sear I that I... Trying to think of a nicer way to say "ruined." Oh, well. I still want to learn how to do this but I'm going to wait until I get another sear, so I always have an original as backup, should I have any other mishaps. This is how we learn! LOL!!!
Title: Re: Trigger Job
Post by: GuitarmanNick on December 07, 2017, 07:09:01 PM
Ideally you want only a little positive engagement and smooth the mating surfaces to ease the trigger pull and then remove a little from the end of the sear at the release point to remove the creep.

Mine was at 8 lbs.+ and still had negative engagement. Honing the sear and hammer to a mirror finish after changing the angle only enough to get a few degrees of positive engagement gave me a smooth 5.5 lbs. on the trigger pull and I no longer have concerns about having a round in the chamber and bumping the gun causing it to discharge. I removed only enough material and at the right angle to give a crisp release point with almost no creep. The result has proven to be an excellent shooter and much safer to handle than the Chineese made it.
Title: Re: Trigger Job
Post by: likemeasks on December 26, 2017, 05:14:18 PM
I agree with some of the above info on trigger mods. Most important of all is to gain about 3/32 inch rearward movement of the hammer while slowly pulling the trigger. Using an ultra-fine honing stone along the contact faces not across them. If you are equipped to really get crazy you can disassemble the trigger group completely and dress up all surfaces that contact each other at the pivot pins. Look closely at the hammer spring shaft and all the levers it travels through. I've seen notches along the shaft that were caused by sharp edges in the holes of the levers and these "catch" as you pull. Dress down the edges and notches with your fine stone. When I did my Romanian I started with considerable negative and an average 9.5lb pull. After, I got it down to 6.9lb with the 3/32 positive engagement. Most will tell you not to, but I cut two coils out of the hammer spring and now have it down to 4.5lb. I cut the spring 1/2 coil at a time and dress the cut to bevel along the angle of the coil wrap. That help prevent binding as the spring compress and expands. Before all of this the rifle would pop milspec primers quite often. Now it will fire all modern commercial ammo and surplus milspec without a single popped primer in 500 rounds. I would caution you that if you are not experienced with working with files and honing stones and small precision fit components it would be best to stop where you are now. And always after doing this kind of work assemble the rifle and with an empty chamber cock the hammer and slam the butt of the rifle down as hard as you can with the safety off on a piece of 2x4 atop cement 4 or 5 times, making sure the hammer does not release.   

Charlie