Saiga 12 problems-next step?

[WarBoy 4]

My buddy and I both built our Saiga 12s at the same time several years ago. I did the conversion work on both. I added the reliability kit to mine and it has been fantastic. Runs cheap bulk pack thru my drum with no problems. He took his home and kept getting FTE on almost everything. Eventually he brought it back to me and I installed a reliability kit in it thinking that would solve the problem. It helped, but still sucked. So I took the gas block off and did the D mod(also cleaned out the gas ports to make sure there were no burrs) that helped tremendously but it still has FTE often(at least 1 out of 5).(using game loads-so slightly heavier than bulk pack)  He did polish the bottom of the bolt and profile the hammer. I'm trying to figure out what to do to it next. I thought about smearing lapping compound on all the moving parts and shooting some heavier loads thru it to smooth everything out. Basically, I'm out of ideas, but want to get this working right for him. What's next?

Edited June 19, 2016 by WarBoy

[HB of CJ 1,263]

If you are comfy with the port diameter and such, you can remove all lube and hand rack and fire the action 1000 times.  Takes time.  Make sure it is unloaded.  Consider nipping off a rim portion of a snap cap if dropping the hammer that many times bothers you.  After completion, take down, clean then heavily lube.  Try the shotgun then.  Three (3) drams equivalent or more. 

[WarBoy 4]

I'm trying in vain to remember what size bit I used to check the ports, its been a couple months.... I think it was a #40?? That would make the ports .098 in diameter. And there's 3 of them. Whats the biggest size you can go up to?

[Mullet Man 2,114]

That should be more than enough port for the thing to cycle.

It's hanging up somewhere else.

What magazines is he using?

What 12g loads is he using?

What handguard does he have on it?

What FCG is installed?

You need to be specific and list everything.

[WarBoy 4]

I've gone through these steps,

 

Stock 5 round mag, tried mine also, no change.

 

Tried Winchester bulk pack (2 3/4 Dr) and some Remington Game loads (3 Dr). Mine cycles with both of these so I figure it should also.

 

Has a railed handguard but the first thing I did was remove it. I've heard they cause problems, no change.

 

I believe its a Tapco G2 hammer and FCG. Hammer has been profiled and polished.

[gunfun 3,931]

OK, I'm going to say this. Adding a 4th port would be good, but I'm going to guess your main problem is that he has a hammer shaped like a trapezoid. That adds a lot of drag to the system.   Also you need to be systematic about what ammo you  are testing against.

 

It's normal for the 2 3/4 dram stuff not to work, but the gun club 3 dram should have.

Make sure you are testing against one specific brand of 3 dram ammo so you can compare your progress.

 

The hammer should be shaped like this:

Er. It looks like the pics are dead in the thread. Gotta fix that.

[gunfun 3,931]

Go to this thread for instructions on hammer profiling, and pics.

 

http://forum.saiga-12.com/index.php?/topic/76775-sweetest-trigger-for-saiga-conversions/&do=findComment&comment=816710

 

I just put new pictures in it to replace dead links.

Edited June 19, 2016 by GunFun

[Mullet Man 2,114]

WarBoy, on 19 Jun 2016 - 11:13 AM, said:

I've gone through these steps,

 

Stock 5 round mag, tried mine also, no change.

 

Tried Winchester bulk pack (2 3/4 Dr) and some Remington Game loads (3 Dr). Mine cycles with both of these so I figure it should also.

 

Has a railed handguard but the first thing I did was remove it. I've heard they cause problems, no change.

 

I believe its a Tapco G2 hammer and FCG. Hammer has been profiled and polished.

 

Hangs up first round, middle, last round? Random or consistent?

What gas regulator? What gas piston? Springs?

[gunfun 3,931]

 

WarBoy, on 19 Jun 2016 - 11:13 AM, said:

I've gone through these steps,

 

Stock 5 round mag, tried mine also, no change.

 

Tried Winchester bulk pack (2 3/4 Dr) and some Remington Game loads (3 Dr). Mine cycles with both of these so I figure it should also.

 

Has a railed handguard but the first thing I did was remove it. I've heard they cause problems, no change.

 

I believe its a Tapco G2 hammer and FCG. Hammer has been profiled and polished.

 

Hangs up first round, middle, last round? Random or consistent?

What gas regulator? What gas piston? Springs?

 

 

He answered this: CSS reliability kit piston and spring. So an overly weak spring, and a piston that provides a very slight boost.

[Mullet Man 2,114]

He sure did, didn't he.

 

So what kind FTE are you experiencing, ejection or extraction?

Is it stove piping or a hull or not cycling at all?

[WarBoy 4]

Yep^ CSS kit. Tried the plug in both directions. Didn't seem to make a difference. It seems like its more consistent on the last round out of the mag, but not always. 

Most of the time it pulls the hull back and it starts to eject but hangs up and the bolt smashes it against the edge of the barrel causing the hull to crinkle up on the edge. Sometimes it rechambers them.

GunFun, I had previously found your link and profiled the hammer to look like you recommend. I think its pretty good.

[VladTepes 160]

OK, I'm going to say this. Adding a 4th port would be good, but I'm going to guess your main problem is that he has a hammer shaped like a trapezoid. That adds a lot of drag to the system.   Also you need to be systematic about what ammo you  are testing against.

 

It's normal for the 2 3/4 dram stuff not to work, but the gun club 3 dram should have.

Make sure you are testing against one specific brand of 3 dram ammo so you can compare your progress.

GF Dram Chart2.jpg

 

The hammer should be shaped like this:

Er. It looks like the pics are dead in the thread. Gotta fix that.

 

I have a 14in gun with a welded brake.. and was having some issues with some ammo.. 

 

that chart has been the single best thing I ever learned here.. I used to think "high brass" "buckshot" etc.. all these random things.. but after seeing this chart I now understand what my gun can and can not cycle.. and no longer waste time trying to figure it out.. I bought some Rio based off of the specs in this chart.. and it fired and cycled every round without issue.. I also cleaned up the hammer a bit.. and cleaned the gun..  now I am pretty sure I am getting a stamp and cutting that brake off since it is running so well.. 

[gunfun 3,931]

Yep^ CSS kit. Tried the plug in both directions. Didn't seem to make a difference. It seems like its more consistent on the last round out of the mag, but not always. 

Most of the time it pulls the hull back and it starts to eject but hangs up and the bolt smashes it against the edge of the barrel causing the hull to crinkle up on the edge. Sometimes it rechambers them.

GunFun, I had previously found your link and profiled the hammer to look like you recommend. I think its pretty good.

 

Your ports are big, but 4 or 5 would be better. If it were me I would add two small ports and step them up as needed. You can take a hammer, chunk of aluminum, punches and a cordless drill with you to the range and do several steps in one trip. Obviously, be sure to have your worst mags loaded full of the baseline ammo. stay systematic.

 

The D mod is not really a great idea. It is overkill and can lead to gas leakage, etc. All that's needed is just enough clearance for an obstructed port if there is one. That's usually easy to obtain by drilling the hole up a small amount, say a bit 1/32" bigger than the original hole in the gas block. Too late for changing that part now, but I guess you have plenty of area to fit additional ports.

[WarBoy 4]

I understand about the D mod not being the greatest but I read from so many people that it worked for them. When I looked in the gas block I could only see two. Initially I thought it came from the batch where they only had two. When I removed the block I was surprised to see the third hole, it was all but obstructed by the front of the gas block. So I just opened it up enough to be able to see that clearly, and put it all back together thinking I found the problem. I don't think it will hurt it, and it did make a huge difference, at least it cycled some ammo.

 

Mullet Man has me thinking that it might not be a gas setting but maybe that the ejector is hanging the shell up. It seems that the shell comes back far enough but doesn't get kicked out soon enough and rides the bolt forward, smashing the front of the case into the side of the barrel/receiver.  Is there a way to test this theory or a guide to polishing the ejector?

 

So if I go ahead and add a 4th hole will it hurt to just make it the same size as the other three? As in, can you have too much gas with these things? I do have the adjustable gas screw, so I could dial it down if needed. I'll get the lowest ammo on that chart and use that as my baseline.

[G O B 3,516]

Check the extractor claw for crap loading up the spring to where it grips the rim of the shell TOO tightly. Disassemble and clean the bolt.

Check the ejector nub for damage -is it chipped or peened? Use the factory recoil and hammer springs.

Make sure that the pins in the bolt are staying put. Sometimes it is necessary to slightly flatten one end of one of them

to keep it from backing out and screwing the bolt from cycling.

Edited June 21, 2016 by G O B

[WarBoy 4]

Per the advice from GunFun, I picked up some Winchester 1200 fps 1 1/8 ounce heavy target loads today. Out of the 25 rounds I had two that stovepiped. They were both the last round out of the factory 5 round mag. Everything else ran fine. Sucks that I can't get it to be reliable on bulk pack like mine is but at least he can shoot it now. As soon as I figure out this issue anyway. Any ideas?

[gunfun 3,931]

I understand about the D mod not being the greatest but I read from so many people that it worked for them. When I looked in the gas block I could only see two. Initially I thought it came from the batch where they only had two. When I removed the block I was surprised to see the third hole, it was all but obstructed by the front of the gas block. So I just opened it up enough to be able to see that clearly, and put it all back together thinking I found the problem. I don't think it will hurt it, and it did make a huge difference, at least it cycled some ammo.

 

Mullet Man has me thinking that it might not be a gas setting but maybe that the ejector is hanging the shell up. It seems that the shell comes back far enough but doesn't get kicked out soon enough and rides the bolt forward, smashing the front of the case into the side of the barrel/receiver.  Is there a way to test this theory or a guide to polishing the ejector?

 

So if I go ahead and add a 4th hole will it hurt to just make it the same size as the other three? As in, can you have too much gas with these things? I do have the adjustable gas screw, so I could dial it down if needed. I'll get the lowest ammo on that chart and use that as my baseline.

 

If you aren't getting ejection it is not from cycling too hard. It's the opposite actually. The hull can't skip past the ejector. What that means is that the carrier either doesn't reach the ejector with the rim of the shell, or it bounces off of that and comes forward and crunches.

 

4@ 0.093" is rather big, and you said 3 @0.098" IIRC. I would start smaller. In any case I would not add more holes bigger than . 093" . No sense having oversize ports and over gassing your gun or letting extra debris into the gas block. I know a few people will blow a gasket over the phrase "over gassing" so I'll clarify. Your gun should have just enough gas for the carrier to reach the trunion with your baseline load, plus a smidge. More is wasted violence, creating recoil, wear, and the possibiliy of carrier rebound related FTFs. Oversized holes and excess gas is relatively easy to restrict, but you still have needless debris.

 

It is easy enough in most cases to get the block off, and you clearly have before. Bring your tools to the range and a couple of drill bits in steps. Practice the motion of drilling the holes at the correct angle with your body braced to allow a smooth follow through. Punch them first, and start at ~90*. As soon as the bit starts to cut, kick the drill to the 20-30* angle you  have practiced. Start small. I have done this in about 15 minutes from start to reassembly.  If I were in your shoes I would add 2 very small holes, say .072" and test at the range. If those weren't enough, then I'd use the next bit up I brought with me. Say .080" Then next would be .084...  It sounds like your gun is pretty close, so I would expect your gun to get where you want to be in one or two steps. Maybe 3. My point is this: Just right is great. I get that you are becoming impatient and just want the gun to work. You can do that. However, getting it just right might be 15,30, or 45 minutes of work at a range trip. IMO that's worth the time on a gun you are going to have for many years.

[WarBoy 4]

Took it apart again yesterday. I had remembered incorrectly. I had 3 ports at .076, way too small. So I stepped them up to .093 thinking I had it for sure this time. Tried it with the same ammo last night and still no dice. It does the same thing, last round out of the mag stovepipes. It did seem like it was crunching on the aluminum part more than the plastic part this time, so maybe it just needs a little more to clear? I pulled the gas block back off this morning and I think I have enough room to fit the two smaller ports, it'll be close.

[WarBoy 4]

Another oddity, last night I noticed that the ejection pattern is about the 1 oclock area. My experience with ar15s would tell me that the gun is overgassed. Maybe I shouldn't drill the two new holes in the gas system and try the original stiffer recoil spring instead of the CSS one?

[Heartbreaker 1,085]

When in doubt, try factory parts. The lighter spring worked poorly on my S12 and I went back to the factory spring. Also if the new puck is clean it may not be sealing enough. Need to shoot some more to get a good carbon seal.

[gunfun 3,931]

Use the standard spring from the factory when doing your tuning, and the rest of the time too. The gun should be gassed such that it runs with a spring which can reliably put the next shell into battery, and can hold the gun locked long enough when firing 3" magnums.

Another oddity, last night I noticed that the ejection pattern is about the 1 oclock area. My experience with ar15s would tell me that the gun is overgassed. Maybe I shouldn't drill the two new holes in the gas system and try the original stiffer recoil spring instead of the CSS one?

 

Don't worry too much about angle of ejection, when you aren't getting consistent ejection. If your gun is not taking every shell past the extractor and the carrier to the very back of the action it is Undergassed/"over-frictioned." If you don't believe me, put some electrical tape on the rear trunion, and see if it is getting smashed up by the carrier. It is supposed to impact, but not so hard as to cause peening.

 

What you would notice once you reach that point is that your ejection angle changes from one load to the next. If the shell is being launched into low earth orbit, that's a good sign you can restrict the gas a little with your gas plug. (Always run any shell on the most restrictive setting on which itcycles 100%)

[WarBoy 4]

Roger that. Left the gas system untouched and installed the factory spring, gas puck and regulator. I'm so close I can smell it! Only 1 FTE using the same mag and ammo. Thought that might be good enough, so I tried my MD arms drum. had 3 or 4 FTE with that, so not up to par. So I believe the next step is to tear it down again and add the two small holes to the gas system. 

 

To recap this far;

 

Stock gas system parts and spring

re-profiled hammer

3 ports @.093"

D mod to gas block

 

Tomorrow morning I'll add two small .072 ports and see where that gets me. Thanks for all your help so far. This one is making me work for it!

[G O B 3,516]

Check mag opening the bottom of the receiver can get bent, especially on the front. That could cause last round FTE as that shell does not have another under

it to raise it to the propper angle.

[gunfun 3,931]

Roger that. Left the gas system untouched and installed the factory spring, gas puck and regulator. I'm so close I can smell it! Only 1 FTE using the same mag and ammo. Thought that might be good enough, so I tried my MD arms drum. had 3 or 4 FTE with that, so not up to par. So I believe the next step is to tear it down again and add the two small holes to the gas system. 

 

To recap this far;

 

Stock gas system parts and spring

re-profiled hammer

3 ports @.093"

D mod to gas block

 

Tomorrow morning I'll add two small .072 ports and see where that gets me. Thanks for all your help so far. This one is making me work for it!

 

Do your testing with the full drum. That will be the worst case scenario. If it runs with that, it will fo sho run with everything else.

[WarBoy 4]

GOB, can you elaborate? I looked at the front part of the receiver where the mag catches. Looks pretty flat to me. But it is the last round every time with the factory mag. Although, with the drum on, they were all at the beginning. I was wondering if maybe the mag drags on the bolt when its empty or something.

 

GunFun, It was a full drum, the FTE were all within the first ten or so rounds, the last ten fed fine. He probably wont ever use a drum on it, but if he ever wants to get rid of it, I know it works properly.

 

I added the two smaller ports, hopefully this works as space is getting tight in there to open it up any more.

[G O B 3,516]

I had a problem with the S-12 FTE on the last round. A straight edge across receiver bottom

showed the sheet metal to be bent down at the front about 1/16". Like most AK problems. I fixed it with a BFH.

[HB of CJ 1,263]

Excellent S12 trouble shooting thread everybody and thank you. 

 

GunFun;  Thanks for the nifty power chart. 

 

Did somebody once post another nifty chart showing real muzzle velocity with very short 12 gage barrels?

[magsite20 1,664]

some of what I look at on these type of guns seeing what you've looked at already the ones in red may still apply:

this is a gas operated gun so you have:

• the gas ports in the gas block
• a piston in the chamber of the gas block
• the bolt carrier group with the op rod that is driven by the piston
• and the recoil spring and its guide rod system that control the cycling of the bolt carrier group

as to what some of the things that can be changed are:

there are 2 recoil springs on the rod the front one can be easily changed with a lighter spring weight from a 1911 to help an under gassed gun cycle (try about 14 lbs) or a heavier spring to reduce power in an over gassed gun. with a little more work the back spring can also be changed if needed.

the piston can be replaced with a bigger diameter tighter fitting piston to get more power for an under gassed gun or a smaller diameter piston to reduce power in an over gassed gun.

if the gun is under gassed the gas ports can be enlarged or ports added this require removing the gas block so is more complicated than some possible changes. this may require an expert / gunsmith or at least some use of a machine shop.

in extreme cases the bolt carrier group op rod could be shortened and the gas block moved back towards the receiver new gas ports drilled old gas ports welded to get more gas in an under gassed gun or a gun with a shortened barrel. let me stress this requires an expert / gunsmith with a knowledge of AK based shotguns. make note getting this done could be very costly on what is a fairly inexpensive shotgun so you really need to think it through.