Auto-Plug tuninig

[Taranscorp 0]

I have to turn the plug all the way in  so it bottoms out and then it tries to eject  the spent shell but it gets caught up in the ejection port. I can't turn it anymore so it will properly eject the shell. When I put in the factory plug screwed all the way in and then back it it out two turns and stop at 2 then the shells all eject properly. I opened up the hole so you can see all four gas ports and they are at .076 

I have a 19" Kavar Sl12-09.  Can a aftermarket puc help me out? I'm trying to shoot Federal 1200fps shells.

Edited September 20, 2013 by Taranscorp

[vulcan16 971]

Is this Randy????

 

Did you put a .076 drill bit piece all the way through the opening? 

Some are not drilled all the way through and may require a little more work.

The aftermarket puc may help enough to get it to run right.

Edited September 20, 2013 by Jet

[Taranscorp 0]

Nope, this is Rich in Tennessee 

Yes the drill bit went all the way through on all four holes.

[poolingmyignorance 2,191]

Your plug is not the problem. An aftermarket puck might help, but no guarantee. You need to ensure that your ports are unobstructed by the gas block opening. It does no good to drill the ports if the opening in the gas block is covering up surface area of the larger ports. Your gun may also require some profiling of the bolt to increase reliability as well.

[gunfun 3,931]

Sometimes 4 @ .076" is inadequate. Most builders use 4@ .078" as a starting point. While some advocate smaller, I think you should do one more step up at least.

 

i.e. remove friction from the action, then increase in small increments (~ .002" steps) from .078 to a max of 4 @ .093". preserving factory angle, or even going a little flatter. If you don't have 100% reliability with solid ejection, bump up a little.

 

Don't spend a cent on a booster unless you need a puck for compliance, and don't waste a bunch of time and frustration without at least bumping up to 4@ .078"

 

Other rational minds disagree, but there's my thoughts.

 

1200 FPS is a good starting point, but you are missing the other relevant #. Namely, at 1200 FPS, you need to be pushing at least 1.125 oz of shot. less weight at that velocity is not likely to work in most S12s.

[poolingmyignorance 2,191]

Sometimes 4 @ .076" is inadequate. Most builders use 4@ .078" as a starting point. While some advocate smaller, I think you should do one more step up at least.

 

i.e. remove friction from the action, then increase in small increments (~ .002" steps) from .078 to a max of 4 @ .093". preserving factory angle, or even going a little flatter. If you don't have 100% reliability with solid ejection, bump up a little.

 

Don't spend a cent on a booster unless you need a puck for compliance, and don't waste a bunch of time and frustration without at least bumping up to 4@ .078"

 

Other rational minds disagree, but there's my thoughts.

 

1200 FPS is a good starting point, but you are missing the other relevant #. Namely, at 1200 FPS, you need to be pushing at least 1.125 oz of shot. less weight at that velocity is not likely to work in most S12s.

Gunfun's advice is sound, larger is better.. just not too large.  What is too large? When you run high brass and break the material out from between the four holes creating one giant hole, you probably drilled too large!

[Bunker83 22]

I had the same problem, tore the she saiga apart and noticed the hammer spring had jumped from where it was supposed to be, to the middle of the trigger . worth a look

[Taranscorp 0]

My  gas block opening has been opened up. The shells are Federal 71/2 shot at 11/8 oz. I really hate to try to get the shotgun apart again it was a huge pia.

I was really hoping the puc would give me that little extra oooomph that I need. The factory plug eject's these shells just fine.

 

Bunker83,

Do you have a pic of where the hammer spring is supposed to be?

Edited September 21, 2013 by Taranscorp

[poolingmyignorance 2,191]

My  gas block opening has been opened up. The shells are Federal 71/2 shot at 11/8 oz. I really hate to try to get the shotgun apart again it was a huge pia.

I was really hoping the puc would give me that little extra oooomph that I need. The factory plug eject's these shells just fine.

Then your ports aren't large enough. If your using the auto plug, go with 4@ 0.93 min. You won't be over gassing so long you stick with 2 3/4". Or you can fight this thing again and again, and pour money into after market parts.

[Taranscorp 0]

What about just  one after market part? After that I open her up I like it or not

 

.093 would be a 3/32" drill bit?

Edited September 21, 2013 by Taranscorp

[burntpowder 23]

The factory plug eject's these shells just fine.

I think you just stated your easiest fix.

[gunfun 3,931]

What about just  one after market part? After that I open her up I like it or not

 

.093 would be a 3/32" drill bit?

 

Yes, but if you can avoid going that big, you want to. the bigger the holes the more crud gets in there. you want the smallest holes which do the job.

[Run and Gun 25]

The MD arms booster PUC is probably the best one to get,it helped me out with crappy light loads.

[Nephilim7 107]

Am I the only one that noticed he backs the plug two turns from bottoming out to achieve borderline performance? Not OK. the plug should function properly when bottomed out and backed out to the first time it crosses "2". That is the setting to use.

 

Try wrapping 5 or so wraps of teflon tape around the plug threads to reduce blow-by the threads robbing the system of gas.

 

Don't be lazy. Pull the block and make sure your ports are exposed.

 

Have you corrected the profile of your hammer? It almost always needs work.

 

When you take out the recoil system and run the bolt and carrier back and forth, is it pretty smooth and easy? Hammer, bolt, and rail work will accomplish this. This is needed before adding gas, in my opinion.

 

If those things are all done, I suggest a fifth smaller port at this point in the game.

[Bunker83 22]

no pics , but, if you take off your dust cover and pull the bolt and carrier out look down at the trigger, there will be two springs running back from the hammer, there supposed to be on both sides of the trigger. One of mine had jumped outa place and landed in the middle of the trigger, it was letting the gun cycle by hand but was pushing the hammer up against the carrier so hard when it was fired it was cuasing failure to eject every round. At first I thought it was the plug (I was pissed) but upon inspection I saw the spring had jumped, put it back were it goes, and she runs great

[Taranscorp 0]

I already filed the  gas block so all of my four port holes are exposed. I took out the factory plug and wrapped teflon tape around the threads and screwed it all the way in and backed out till it clicked on 2 and went outside and it ejected better than before..Should I try again with the auto-plug again?

[menace667 194]

This may be no help what so ever, but more an observation from a previous auto plug owner who had the same issue. I had a Saiga prior to my VEPR and it would run almost any ammo I put in it, to include under powered crap. I purchased an Auto plug to keep me from having to adjust the gas system because I liked shooting all kinds of mixed loads and did not want lots of premature wear from over gassing. Once installed it would never work properly. Even bottomed out, as you describe, I could not get it to "tune" to light loads. I even went to hotter light loads and no luck. I took it out and handed it to another forum member here who was shooting with me and he installed it on his SBS and his stock shotguns and it worked no problem so the issue had to be my gun. I eventually traded it to him for his V-plug and was as happy as I could be with that.He still had and uses the autoplug without any issues to this day. 

 

The person who was shooting with me has more technical acumen than most vendors on this site an had already made my gun run "like a raped ape", so no amount of port work was worth taking the risk of damaging my gun. It had already had re-profiling of the bolt, carrier, hammer, and polished to a mirror shine and all that other jazz. 

 

Some guns will not work (anything can be made to work but at what cost and risk) with certain modifications is what I learned from this situation. 

[grima 15]

Easy Fix :-

The auto plug has 4 parts as you now. The problem part is the adjust screw.

AS you tighten it the spring moves of centre, causing uneven pressure on the valve.

The result is LESS pressure for the valve to open, NOT more.

 

The Fix :-

Take it apart

You need to put a spot weld on the flat side of the adjust screw in the centre

Then file it round so the spring fits over the weld, it only needs to be 2mm high

Put it back together

Now as you tighten the adjust screw the spring stays central to the valve.

It now will need more gas pressure before it will open.

 

I had the same problem until I tried this, never looked back

[gunfun 3,931]

There have been a couple guys who had guns that otherwise ran properly with the stock plug and could not get them to work with an autoplug bottomed out. When that is the case, it obviously had to be the autoplug. 

 

Grima pointed out one way an autoplug could fail: spring stacking or shifting.

I can think of a few others,

• just plain bad spring. a weak one. I'm sure it happens from time to time. If so, a new spring would fix it. This one seems most probable to me.
• some kind of defect in the threads on the adjustment screw or plug body which prevent it from screwing in all the way
• a defect in the poppet valve which prevents it from seating properly, thus venting more gas than desired. 
• oversized vents in the plug.

[pedal2alloy 206]

Easy Fix :-

The auto plug has 4 parts as you now. The problem part is the adjust screw.

AS you tighten it the spring moves of centre, causing uneven pressure on the valve.

The result is LESS pressure for the valve to open, NOT more.

 

The Fix :-

Take it apart

You need to put a spot weld on the flat side of the adjust screw in the centre

Then file it round so the spring fits over the weld, it only needs to be 2mm high

Put it back together

Now as you tighten the adjust screw the spring stays central to the valve.

It now will need more gas pressure before it will open.

 

I had the same problem until I tried this, never looked back

 

 

That's really interesting.

 

Instead of adding some weld to the center, maybe you could profile the screw end with a dremel to make a seat for the spring to keep it centered 

[grima 15]

There have been a couple guys who had guns that otherwise ran properly with the stock plug and could not get them to work with an autoplug bottomed out. When that is the case, it obviously had to be the autoplug. 

 

Grima pointed out one way an autoplug could fail: spring stacking or shifting.

I can think of a few others,

• just plain bad spring. a weak one. I'm sure it happens from time to time. If so, a new spring would fix it. This one seems most probable to me.
• some kind of defect in the threads on the adjustment screw or plug body which prevent it from screwing in all the way
• a defect in the poppet valve which prevents it from seating properly, thus venting more gas than desired. 
• oversized vents in the plug
• ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Grima's reply

 

1 Bad spring :- Then why does it work in someone else's saiga ???????? 

2 Remove spring, screw in all the way to check it bottoms out  

3 Check valve + seating in plug, not rocket science!!!

4 Doesn't matter how big the vents are?

I don't waste my time talking shit.

People do what I tell you & stop listening to fucking maybe problems if you want your Auto plug to work.

If your S12 worked with the standard plug OK, then this fix will work

No fucking wonder I hardly ever  post on this site

 

Edited September 21, 2013 by Grima

[pedal2alloy 206]

Cranky

[grima 15]

Cranky?????

I say TAC 47, Will Mod There Auto plug, LIKE I SAID

I will get fuck all for it.

Just putting them straight, because it's a good product

[gunfun 3,931]

It is a good product, which someone apparently shipped to the UK.

 

I'd appreciate it if when you quote me, you don't put your words into my quote bubble.

All my points are and were valid, and would take very little time to check.

[grima 15]

http://youtu.be/sTlbs5ZwvksI   watch vid & see what I mean    

 

I shall never enter your bubble again Mr Gunfun

 

I found it under a tree while out for a walk "honest"

 

When I fitted the auto plug, I tuned it for low brass It worked OK.

Switched to high brass, worked OK.

Went back to low brass, It didn't work FTE

 

So what had changed?

 

If you hold the plug in your hand , looking at the valve.

with your other hand turn the adjusting screw, you will see as you turn the valve is all over the place. 

the spring is not staying in the centre.

If the spring isn't in the centre, the valve isn't. Lost pressure 

 

So the spot weld keeps the spring in the centre and the valve in the centre

Result constant even pressure every time the valve opens and closes.

Worked for me

 

You also loose gas around the threads

Edited September 22, 2013 by Grima