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Not enough gas?


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Hi newbie here. After having my s12 for a year and firing 5 rounds through it, I finally decided to convert it. So I read just about every thread here, ordered the parts and had it done in about 2 hours. When I went to shoot it I ran 30 rounds of 00 buck and 100 rounds of federal bulk. The problem is that it would only cycle the buckshot on setting 5 of my v plug. The federal wouldn't cycle at all had fte's on every mag on setting 5. So I set it to setting 5 in the next round of settings and same problem I don't really want to scr ew the plug out any further. The mags I were using were sgm 10 rounders and an MD drum. I'm thinking the gas ports aren't big enough. I can see 3 ports but I haven't taken the gas block off to check for a 4th yet. Any suggestions I don't really like the idea of polishing anything because if I get deployed I don't want to come back to a rusty shotgun.

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Slow down. Relax do things in order.

 

200 rounds might just be a waste of 200 rounds.

 

Don't polish anything yet. You want to get it basically running right before that should matter anyway.

 

Let's eliminate variables methodically:

 

Put everything back as close to factory as you can. factory puck, plug fore-end Everything you can.

 

Also find a piece of wire like a small paper clip and probe for your ports. If do a full field strip including the stuff in the gas tube, you ought to be able to put a light in there and see all the ports from inside the barrel. If you don't understand how to do that safely you need a different platform.

 

Next, tell us what you are working with. Complete part list and specific ammo goes a long way.

 

Things to check and cleanup first.

 

1) take off the dust cover. Take off the main spring.

2) slide the carrier back and forth and feel for hangups. Get some light sandpaper and alcohol and a rag and get the paint and burrs off of the rails. They are parkerized. Don't worry about rust. This should be slick. - does the bolt hang up on the hammer or trigger components? ...

3) after doing this go to walmart and get some of the cheap federal 1 1/4 oz shot. and some of the normal 3 dram 1 1/8 oz shot. (so you can figure out just where it quits.)

 

4. Go to your range. Put in the factory plug (and tappet/puck) Screw it all the way in until it bottoms out. Back it out to #2. Try a couple shots of the 3 dram. If it isn't working bump up to the 1 1/4 oz. If it works you are just a little undergassed. This is a place where screwing with gas ports or a major bolt profile starts to make sense. If not, then you certainly need gas ports done.

 

Also shoot a couple of buck on #1 with the factory plug. Do they eject with enthusiasm? They should.

 

Take two and call us back in the morning.

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Looked at it a little bit more and the hammer hits the bcg and the bolt pretty bad. At the worst point it looks like it pushes the hammer down every bit of a quarter inch. When the bcg and bolt aren't hitting the hammer it slides smooth. But it takes a bit of force to get the bolt to rotate and lock into battery when it gets to that point.

 

Parts list

Modified trigger group from CSS

CSS trigger guard

JT engineering main spring

Axis pin retaining plate

CSS internal block

Tromix stock with limb saver and cheek riser

ACE push button side folding mechanism

Saw grip

MD arms v plug

Tromix shark brake with barrel nut

Chaos titan backorderd

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As far as ejection is concerned, you are really only worried about hangups while pulling the bolt back.

 

It is normal for the hammer to be pushed down some, but that issue is part of the profiling. It needs to go down far enough to go past the disconnecter every time, plus a bit. Also it is pretty normal for the face of the hammer to get surprisingly ugly from peening. The bolt smacks it and it is deliberately softer metal than the bolt so that the cheap part takes the wear. Therefore it needs a little extra meat to allow for wear.

The hammer should hit the firing pin surface square on when the bolt is home. If you profile it wrong, it will hit at an angle and be putting a side load on your firing pin and not go all the way forward.

 

So when you test it use the factory plug. None of the other parts should matter, and you have the standard G2 FCG that Tromix alters. It is probably ok but they are profiled to work very safely in the broadest range of saigas not fine tuned to yours.

Rails like the titan sometimes do affect cycling, but not often.

 

The JT spring is specifically made so that you can tweak it to be softer or stiffer as needed. Softer would reduce force needed to cycle and give a little softer trigger pull. Too soft gives light primer strikes.

 

One thing to check is whether your bolt snags on the topmost part of the retaining plate under the rail. If so, shave a bit off of the top of that. This is a common issue.

Edited by GunFun
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Pretty good info given above.

I'll add....

If you have the ability to measure using dial calipers, measure the thickness of the OEM hammer (the area where the carrier makes contact) and then measure the new hammer you're using. If they are different, remove excess material (dont get crazy) on the new hammer, until it matches the thickness and shape of the OEM hammer. You can also reinstall the OEM hammer for diagnosis and then fire it and see if it makes a difference in performance. If so, and you need the US hammer compliance part for the 922r count, then reshape the US hammer to match the OEM hammer.

 

Polishing parts actually helps prevent rusting by smoothing out and closing up inconsistency ('pores') in the metals surface.

 

A cheap way to help 'break in', is to hand cycle the action until your arm is dead tired. Then switch to your other arm and do it again.

 

Saiga 12's are not created equal and the majority need some user input to get them running 100%.

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I've confirmed that it has 3 ports using a paper clip, I don't know what size they are though. I reinstalled the factory gas plug and went to the range.

 

Ammo used

Federal 2 3/4, 1 1/8 oz shot 8 shot, at 1145 fps

federal 2 3/4, 1 oz shot 7 1/2 shot at, 1250 fps

Remington 2 3/4 1 1/8 oz shot 7 1/2 shot, at 1300 fps

Winchester super x 2 3/4 00 buck

 

The 2 kinds of federal fte in all the mags including the factory 5 rounder. They didn't even make it out of the tube but did reset the trigger.

The Remington worked in all mags pretty well but still fte once per mag. I managed to get 16 rounds out of the drum before it fte, that was awesome :).

All were on setting 2 of the factory gas plug.

I then switched the plug to setting 1 and fired the buckshot in the factory mag and ran flawlessly the empties ejected about 4 or 5 feet.

 

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Well I pulled out the dremel and ground a little bit off the hammer its just a little thinner than factory now. I then polished the hammer and tested it to make sure it struck the firing pin correctly and it does. Then I took the edges off the bottom of the bcg that slides over the hammer and polished that up. It slides much smoother now. I still need to polish the bolt but thought I'd save that for tomorrow.I then decided to remove the gas block and see what my port sizes were. One fit a 3/32 bit very snugly. The other 2 I could only get the bit to go in about an 1/8 inch. A 1/16 bit fit those 2 ports somewhat loosely. I'm thinking this two are too small.

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If you are comfortable with possibly removing your gas block a second time around, I suggest cleaning out the gas ports with the smallest size drill bit you can that will remove the least amount of material. It doesnt take much to get the gas flow it needs.

 

There are mainly two schools of thought that i've seen on here.

First one is drill out all the ports evenly and large, then regulate the flow down with some aftermarket gas plug (TAC47 Auto plug, MDArms V-plug, GunFixers gas plug etc.).

Second is just barely clean your ports with small bits and possibly open one of them to a single bit size larger then the other two, until it runs with the OEM gas plug (i personally subscribe to that).

I favor the second as it really keeps gas block contamination down to a minimum. I've gone ~500rds without cleaning the GB and she wasnt showing any signs of slowing down.

 

My personal S12 runs like a scalded ape. I have 3 ports, 2 @ 5/64" and 1 @ 3/32", plus the "D window mod" and BCG polishing and profiling by Pauly.

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go 3/32 on all the holes. I'd even do over the one that fit the 3/32 just to make sure its clear, then before you put the gas block back on, check that nothing is hanging in the ports from the drilling. Were all 3 ports completely uncovered by the gas block, if so then just reinstall the GB, if not file it out so that it would leave you three completely open ports

 

I just wanted to add that most including myself shoot the burs out that hang in the barrel, by shooting small shat after the drilling and reassembly is complete

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