DIY trigger work on an SAR-1

[eagle59]

I’ve had my SAR-1 for few weeks now and I continue to “tweak” it. I stoned the HTS engagement surfaces and polished them smooth with the good old Dremel. The trigger pull is long and smooth now. This rifle also had the awful trigger slap that makes your finger numb after a few mags. I did the disconnector mod to see if that problem is fixed but I won’t know if that worked until this afternoon.

Has anybody done clean-up on the trigger to shorten the length of the second-stage pull? It looks like you can carefully remove a little material from the back of the trigger surface where the hammer is released to accomplish this. Has anybody had luck with this?

Now before anybody suggests I just go and get a replacement group from Red Star, I’ve thought about it. That’s my backup plan. I don’t want to create an unsafe condition or cause doubling (or worse) or anything like that. I’m just wondering if anybody else has tried this.

What say you…

[avatarhammer]

Always be aware that you may screw up the heat treating on any part you smooth up. That being said, I've shortenened the pull by shortening the hook(s) on the trigger. Done both double and singles. Screwed up one and had to take alittle of the safety sear to get it to rotate a little further forward to maintain the second stage. Can't match the Red Star's for crispness, but came pretty close. If you screw up the century parts and have to get a Red Star you'll be out some bucks but you'll have a damn fine trigger that's very adjustable -- you definitely will not lose. Be careful and good luck.

[eagle59]

Avatarhammer

About that heat-treating thing. Do you think that’s a problem? The engagement surfaces on these parts is very generous. These are robust parts. When I ground off and removed the material from the disconnector, I did not allow the part to get too hot so it should not have lost hardness or gotten soft.

On AR15 triggers and hammers, you can’t do much grinding or polishing because I understand they are only surface hardened. The points of contact between the hammer and trigger is very small when compared to AKs. If you break the surface treatment, the parts will wear quickly. The geometry on the AR triggers also puts more pressure on the contact points. It looks like the load is spread over a huge contact area on the AK trigger and hammer. A double hook trigger would seem to be even better in spreading the load. Should I be watching these modified parts for wear? It looks like I’d have to do an awful lot of shooting to wear these parts out! I’m up to that challenge though. If I’ve got to spend for time at the range, it’s a sacrifice I’ll have to make! :D

[avatarhammer]

I wouldn't worry too much about it. Never hurts too keep an eye open though. I always check when cleaning. Sacrifice -- yeah it's hard. Burn that ammo up! :AR15firin

[droog]

One of the first things to do is check and see if the sheperds hook is installed right .Some of those have the big end hooked around the hammer pin and that is wrong it is supposed to be hooked to the center support and run over the top of the hammer pin and under the trigger pin. That makes a big difference in the pull on the three of them I have worked on.

[Packrat]

You don't want to remove anything off the surfaces. There is some roughness on the surfaces that you may have to take off, but be VERY careful about it. And don't, whatever you do, change any of the angles. What you want to do is smoothe the surface, then polish it till it looks like a jewel.

The trigger will become very smooth, but the pull will still be long. Don't try to shorten it unless you have found a way to make the pull a lot greater--in the absence of the roughness and the weight of pull, you need that long pull.

[eagle59]

Well maybe I’ll just leave the trigger as-is for now. I don’t want to risk anything by trying to shorten the length of the second stage pull. I wanted to get an off-the-shelf AKM knockoff. That’s what I got and it’s kewel! :cool_smal

We took it out to my in-law’s gravel pit yesterday and had some after-dinner fun. My borthers-in-law and nephews put a couple hundred rounds through it. We were shooting at some gourds/squash and cans. I had some Wolf hollow points that threw gourd-guts all over the place! The Barnaul FMJ stuff we had was not so spectacular on squash but was kind of interesting. The sky was overcast and gloomy. You could see sparks flying when the bullets smacked into the dirt. These must be copper washed, mild steel cased bullets or something since a magnet sticks to them. Anyway, it caused the sparks to fly when they hit the dirt and that was kind if neat!

Will the shepherd’s hook really affect the trigger pull? When I got the rifle, it was installed on the hammer pin, curving under the trigger pin. In subsequent re-assemblies, I have had it in both ways. Currently it’s on the cross-pin, over the hammer, under the trigger. Which do you like better?

[droog]

That is the correct way to do itIts a lot easier to take apart that way.That hook drags on the spring and adds agrittier feeling.It will not releive the slap from the trigger though.The back of the disconecter needs to be re shaped to do that.All in all it is easier to invest in a better trigger like a FSE or a Gordon tech or K-var trigger group.

[eagle59]

We burned up some more ammo this weekend. The trigger-slap is still present. I did the modification to the disconnector as described on LINX310's site but it's still there. It does not seem to be as bad as it was and it varies from shot to shot. I'm wondering if I took off enough material from the bottom of the disconnector, near the spring hole. Has anybody else had better luck with this procedure? Is it possible that the force of the hammer, engaging the disconnector hook on recoil, is so great that it's rebounding back until it contacts the back/bottom of the trigger?

I may just have to go out and get a better HTS group.

[CAMPYBOB]

It does not seem to be as bad as it was and it varies from shot to shot. I'm wondering if I took off enough material from the bottom of the disconnector, near the spring hole.

remove some more material from the disconnector and radius a blend into the vertical surface.

you might want to get a couple of spare disconnector springs and experiment with shortening the spring a quater coil to half a coil.

[Jonnie G. Tyler]

I had good luck using the described method.

But I ordered a Red Star plate to replace the shepards hook and their diconnector spring. This spring will help reduce the weight of pull. I did a bit of polishing while the parts were out and the trigger is now much better.

But on of this winter's projects is to really polish the dickens out of the trigger and hammer. See if I can't make a really nice trigger out of this, or totally screw it up and have to order a Red Star trigger. Either way, I'll make a really nice trigger out of it. :small_gri

[eagle59]

Okay, now I’m not following here. Forgive my ignorance; I’m a newbie to these AKs. I’m not tracking with how the shepherds hook affects the trigger pull. :huh_small The only thing it does is keep the trigger and hammer pivot pins in place, right? It does not look like it’s supposed to prevent the pins from rotating but if they do, so what. The only things the hook touches is the groove in each pin and the cross-pin, if that’s how you installed it. Are the pins supposed to spin in the receiver or stay put and the associated parts rotate around them? Is that what makes a difference in the trigger pull? It does not look like the lowly shepherd’s hook (or retainer plate for that matter) would make any difference in trigger pull. If he did not want the pins to move, wouldn’t Mikhail have engineered them with a flat to prevent it?

Go easy on me! I’m a pilgrim in these here lands but I want to know.
:confused:

[droog]

You are correct if the hook is put in properly but when they hook it to the hammer pin it binds on the hammer spring on one side and it binds enough to notice the difference in pull when it is hooked on the center support like it is supposed to be hooked.

[flipster]

With a Gordon Tech HTS set, what would cause doubling? Should the set be replaced?

Thanks..