1st S12

[Ronin38 2,117]

Check the gas ports First!

 

 

[FunkedOut 91]

Check the gas ports First!

 

read the first two posts of this thread.

the gas ports look fine. I haven't measured, but more importantly, this gun ran fine out of the box.

it's obviously something I changed.

[The_Caged_Bird 474]

Check the gas ports First!

 

read the first two posts of this thread.

the gas ports look fine. I haven't measured, but more importantly, this gun ran fine out of the box.

it's obviously something I changed.

 

Yes, and no, I'm betting that it's the hammer, AND slightly under-sized ports...

[vicdoc 38]

Needs some smoothing and polishing. Ports are really easy to deal with but you then need a V-plug for finer gas regulation.

[The_Caged_Bird 474]

Needs some smoothing and polishing. Ports are really easy to deal with but you then need a V-plug for finer gas regulation.

 

Agree to disagree, yes he needs a tunable plug, but you can only get so much gas through a port unless you pressurize the gas. They haven't really figured out how to turbocharge guns so a small increase in port size will do wonders...

[FunkedOut 91]

my thoughts on this are to make the gun work with 00B on setting 1 and low brass on setting 2 of the factory gas plug. that is the baseline.

it worked out of the box. how could it be undergassed? I don't see it.

I changed things and now it doesn't work. changing other aspects of the system to compensate for what I changed is not wrong, but is not how I want to approach this. I will modify what I changed until it works again.

 

I agree, opening up ports is not hard to do.

I have an auto plug standing by.

I won't touch either of those until I get it to work like day one with the new components I put in.

 

Sunday, I'll shoot it with the Russian hammer and hopefully confirm that my hammer profile is the only problem.

Edited February 18, 2012 by FunkedOut

[FunkedOut 91]

well, shot it today and it's not the hammer. the FTE's continue.

 

I did some more observation on the jams and found that every time, the bolt cycled back far enough to reset the hammer, and far enough back for the bolt to strip a new shell and start it into the chamber. the empty case is gripped by the extractor well, but doesn't leave the action.

 

when i cycle it by hand, it looks like the ejector isn't hitting the case high enough to kick it to the right. it just kicks it straight up. is this a common problem?

 

also, shooting 00B on setting 2 doesn't make it go away.

 

thanks in advance for any help, thoughts, comments or suggestions.

[Spartacus 1,619]

Check the gas ports First!

 

read the first two posts of this thread.

the gas ports look fine. I haven't measured, but more importantly, this gun ran fine out of the box.

it's obviously something I changed.

 

 

It's one of two things... less gas, or more drag on the action.

 

I doubt it's an ejector problem if you didn't change it at all. It's probably just that the action no longer has enough force to punch out the empty shells.

 

Try using a paperclip to clear out the gas ports, there may be shavings stuck in them from all of the (very nice) work you did on it. Also, maybe the gas plug is not at the same position as your initial testing. Crank the plug all the way in and then back it out to the number 2 position and try some of that 00 buck again and see if it ejects now. If not, then back out the gas plug one full turn until you get to the number 2 position again, and then try another few test rounds.

[evlblkwpnz 3,418]

....

I shouldn't have eaten that last bowl of chili.... tummy hurts.... may be gas.... and I am wondering if there might be a little something caused by that Arsenal FCG.

 

 

Edited February 20, 2012 by evlblkwpnz

[FunkedOut 91]

i looked at the FCG a little closer. there is nothing wrong with the arsenal FCG if you use it on an AKM, as it is a spot on reproduction of just about any comm-block FCG i can lay hands on.

the issue is that the Izhmash factory S12 FCG has a slightly different geometry, most notably the height of the sear. The Izzy sear holds the hammer lower (further from the bolt carrier) than a standard AKM sear. The disconnector and hammer engagement don't change any, if at all.

I will post some comparison pics once I get my hands on some more US FCG's.

 

so I made a quick and dirty test configuration for the Izhmash sear to see if that makes my troubles go away.

[Ronin38 2,117]

^ World's First Adjustable Trigger for the S-12!

[FunkedOut 91]

it's already got a Mk2 version; locking nut.

if this works out, i'll turn down the Izhmash trigger, get some threads on it, screw it in, and braze it.

just a thought...

[The_Caged_Bird 474]

You are going to some awfully extreme steps when all that is needed is to open up one or more gas ports...

[FunkedOut 91]

chasing the dragon, i guess.

thanks for keeping up and offering advice.

i'll get there from here.

[FunkedOut 91]

I managed to get my hands on a couple more US FCG's to compare. Here are some pictures of the Izhmash S12, Red Star Arms, Tapco G2 double hook and the Arsenal S12 FCG's:

 

 

The Red Star Arms and Tapco need to be cleared for the BHO lever. Arsenal does not. No biggie.

 

The hammer profiles are all a little different and all could use some profiling/polishing. Again, no biggie.

 

Now, the focus for me on this exercise was to compare the sear geometry. It was difficult to capture this in a picture, but here goes. Notice how some sears are lower than others:

 

 

 

 

 

 

From looking at the different groups on the same pin, I would say that the Red Star Arms FCG holds the hammer lower than the rest, followed closely by the Izhmash S12, then the Tapco G2 and lastly the Arsenal S12.

I decide to try and quantify (measure) the differences.

 

This next pic shows the best measurement I came up with, short of installing in the receiver and measuring the hammer off the top rail:

 

Here are the numbers:

• Izhmash S12 = 0.495"
  
• Red Star Arms = 0.497"
  
• Tapco G2 = 0.572"
  
• Arsenal S12 = 0.669"
  

Although the Red Star Arms sear is lower than the Izhmash S12, it is also further forward, accounting for the longer measurement.

 

After all this, I concluded that the height of the sear shouldn't affect the cycling of the action when fired. When the shotgun is fired, the trigger is back and the disconnector holds the hammer until the trigger is let go, after the bolt carrier closes. If you look at all the disconnectors, they all hold the hammer in the same position.

The only effects of sear height would be lock time and hammer strike force. The lower the hold point, the longer the lock up time is, and the greater the force will be imparted on the firing pin. I'd say for my purposes, both of these effects are negligible. I've never suffered a weak hammer strike from the Arsenal S12 FCG and the lock up time for the Izhmash FCG seems instant to me. I haven't quite mastered the Matrix yet.

 

eta: Also, racking the bolt carrier while the hammer is back (like when emptying the chamber) is much easier with a lower sear geometry. No biggie.

 

Anyway, I figured I'd share the pics. Gotta get out and test my shotgun with the Izhmash FCG. I can't imagine the gun working great out of the box for 200 shells and then stop working because of furniture and trigger guard relocation. I need my world to make sense.

 

Edited February 23, 2012 by FunkedOut

[Ronin38 2,117]

Very informative! Thanks for all the pictures. Good Luck with it!

[The_Caged_Bird 474]

Wow! Nice write-up!

[FunkedOut 91]

managed to test out the S12 today.

 

Izhmash FCG, puck and gas plug:

1. with the plug bottomed out and backed off to position 1, 00B FTE 20% of the time.
   
2. backed off to setting 2, 00B ran beautifully, lo-brass FTE 100% of the time.
   
3. backed off more to setting 1 like Spartacus suggested and 00B ran perfectly. thanks Spartacus.
   

then I changed out the factory gas plug for an original Gunfixr plug:

1. position 1-, 00B FTE 100% of the time
   
2. position 1+, 00B FTE 100% of the time
   
3. postion 2, 00B ran perfectly, lo-brass FTE 100% of the time
   
4. position 3, lo-brass FTE 100% of the time
   

so I changed out that gas plug for a Tac 47 auto plug. with the spring tension screw bottomed out, lo-brass would FTE 100% of the time but 00B was flawless.

 

now I'm still confused because, I'm certain that it ran out of the box with the factory plug bottomed out and backed off to position 1. the only changes are the trigger guard and furniture. the gas ports were inspected and cleared/cleaned before each session. makes no sense. so much for my world making sense.

 

my last ditch effort to make heads or tails out of all this is that stresses added to the receiver from the new trigger guard have added more drag to the action, which now requires more gas to operate?

or, the sporter stock geometry is better for the cycling of the action than a pistol grip and stock geometry?

maybe a bit of both? the world may never know.

 

bottom line is, more gas makes it run. guess I'll stop chasing the dragon and get with the program; the "gas it" program. I plan to take it real slow and test often, only porting as little as is needed to make it run with the Izhmash FCG, the drop in the Arsenal. if that breaks it, I'll adjust that FCG until it runs again.

 

thanks for the advice and putting up with me while I caught up.

 

on board.

[Scorch95 1]

In my iz-109bho s12 the RSA trigger was drop in although I had to clearance the safety like no other. But my bho is a lot different than the standard one.

[Boomstick12 11]

well, shot it today and it's not the hammer. the FTE's continue.

 

I did some more observation on the jams and found that every time, the bolt cycled back far enough to reset the hammer, and far enough back for the bolt to strip a new shell and start it into the chamber. the empty case is gripped by the extractor well, but doesn't leave the action.

 

when i cycle it by hand, it looks like the ejector isn't hitting the case high enough to kick it to the right. it just kicks it straight up. is this a common problem?

 

also, shooting 00B on setting 2 doesn't make it go away.

 

thanks in advance for any help, thoughts, comments or suggestions.

 

People have told you the problem you choose not to listen. GAS PROBLEM.

[evlblkwpnz 3,418]

Gas operated weapon designed to fire slugs and buck needs more gas to run bulk birdshot. Who would have thought it?

 

Seriously, the Arsenal FCGs are not ideal for use in a Saiga 12. Do a little work to that G2 and you will be a happy guy.

[The_Caged_Bird 474]

Gas operated weapon designed to fire slugs and buck needs more gas to run bulk birdshot. Who would have thought it?

 

Seriously, the Arsenal FCGs are not ideal for use in a Saiga 12. Do a little work to that G2 and you will be a happy guy.

 

I agree, the Arsenal holds the hammer too high for my tastes, I'm sure I could achieve better results with other brands but I've got a sub 4lb trigger pull with my G-2...

[FunkedOut 91]

man, am i glad you chimed in Boomstick12. especially because of what you chose to quote me on.

I had forgotten all about setting 2 not cycling 00B with the Arsenal trigger and disconnector. I'll keep that in mind when I stick the Arsenal FCG back in.

 

you're probably right evlblkwpnz, the Arsenal FCG is not ideal, but I own it. The G2 isn't mine. I'll try to make the Arsenal work, but won't bang my head against that wall too long.

 

I'll try the Arsenal trigger and disconnector with the Izhmash hammer first and get that working before I put the Arsenal hammer in. All this after I get the gas sorted.

[gunfun 3,931]

Doing the gas work and going slowly is the right choice. It is less work than you have already done.

 

Since you have both, I would vote for using the RSA. I have both an RSA and A nicely Modded G2. The engagement angles and ability to adjust the position and tension on the disconnector make it better than a G2 that has been modified for take-up and overtravel. Interesting point you made about throwing the hammer further and harder. I never thought of that, but in theory it means you could get away with a little lighter hammer spring.

[evlblkwpnz 3,418]

man, am i glad you chimed in Boomstick12. especially because of what you chose to quote me on.

I had forgotten all about setting 2 not cycling 00B with the Arsenal trigger and disconnector. I'll keep that in mind when I stick the Arsenal FCG back in.

 

you're probably right evlblkwpnz, the Arsenal FCG is not ideal, but I own it. The G2 isn't mine. I'll try to make the Arsenal work, but won't bang my head against that wall too long.

 

I'll try the Arsenal trigger and disconnector with the Izhmash hammer first and get that working before I put the Arsenal hammer in. All this after I get the gas sorted.

I don't have an Arsenal FCG in hand to test myself (though I bought some from KVar once and sent them back the same day I received them, garbage), but it looks as if the Arsenal hammer would need to travel more on each stroke to allow the carrier to move rearward and forward across it. The less work the carrier needs to do, the less gas will be required to cycle the weapon reliably with light loads.

 

Absolutely no weapon that I have experienced in my lifetime compares to the S12 when it has been refined and made reliable. There is more to it than just sheer reliability, though that is the main goal. Reduction of felt recoil and the ability to remain on target during rapid fire is also part of the goal during the refining process. I want to see you get there.

 

With a 18-19" barreled Saiga 12, you should need no more port surface area than 4 ports @ .093" to eject reliably if all else in the weapon is as it should be, including the FCG. The factory FCG should be fine with a little work if you have enough US parts elswhere to be compliant, as it appears you do.

[FunkedOut 91]

...Since you have both, I would vote for using the RSA....

 

unfortunately, I don't. all I own at the moment is the Arsenal.

The RSA is top notch, but it is $$$ and more importantly, I'm not a fan of set screws when it comes to reliability.

I'll see how the Arsenal works when the time comes. I would really like to make it work, as all my AKM's have that FCG. I would like to have this trigger feel the same. All my AR's have the same trigger too. I'm funny like that.

 

sure, this is way more work than just gassing it, but this is my 1st S12, and I prefer a hands-on education.

still don't know for sure what changed during the conversion, but I do know it wasn't much. this as far as I'm willing to go.

 

Thanks for that number evlblkwpnz, I was going to search around for that info.

[The_Caged_Bird 474]

It's great to know the reasons behind what we do, if no one tries to think of something different from time to time our solutions never evolve or get better. Hey, the best inventions in the world are products that were made by total accidents...

[lbsrdi 1,078]

It's great to know the reasons behind what we do, if no one tries to think of something different from time to time our solutions never evolve or get better. Hey, the best inventions in the world are products that were made by total accidents...

Like antifreeze.

[evlblkwpnz 3,418]

It's great to know the reasons behind what we do, if no one tries to think of something different from time to time our solutions never evolve or get better. Hey, the best inventions in the world are products that were made by total accidents...

Caged,

Your ESP is kicking ass today. That trigger idea lead me to a thought that made me think of a major dimensional change to a product that I was about to move forward with submitting to Tapco. Funny how that works.... time to patent lawyer up.

 

OP,

No problem. Most experienced members here are willing to help. We see cycles of this problem and that problem, all of the time, and we try to sprinkle enough knowledge here and there to keep the newer guys interested in these fine weapons long enough to get them reliable and become S12 addicts, like us. The Saiga 12 is my favorite weapon of all that I have ever owned.

 

I can merely hope that others will be fortunate enough find the same joy in them that I do.

 

See sig line ....

Edited February 26, 2012 by evlblkwpnz

[Boomstick12 11]

man, am i glad you chimed in Boomstick12. especially because of what you chose to quote me on.

I had forgotten all about setting 2 not cycling 00B with the Arsenal trigger and disconnector. I'll keep that in mind when I stick the Arsenal FCG back in.

 

you're probably right evlblkwpnz, the Arsenal FCG is not ideal, but I own it. The G2 isn't mine. I'll try to make the Arsenal work, but won't bang my head against that wall too long.

 

I'll try the Arsenal trigger and disconnector with the Izhmash hammer first and get that working before I put the Arsenal hammer in. All this after I get the gas sorted.

 

Yeah, well, people told you, almost righ away what it was, and you choose to not listen to them. "huuurrr, well, I'm gonna try this...DOH! It didn't work, I wonder why? Can anyone tell me? "Gas problem".....Hurrr, I'm gonna try something else,,,DOH, it didn't work....WHY???"

 

You straight up asked, people who KNOW what they are talking about TOLD YOU, and you didn't listen.

 

What do you expect? I mean, you ASKED. ASKED, when you didn't even have to. SEARCH button. Others have had the same problem as you. I've seen the threads.