Best Saiga gas puck

[aresv 49]

Now think about this for just a moment. Increasing the volume of the gas chamber actually works against you. Theoretically speaking, if you had a 10 foot gas tube with the puck at the end, MOST of the gas being vented into the tube would go to work compressing the pre-existing gas (air) in the tube. The amount of work being done on the puck would be greatly minimized.

 

If anything, I would suspect that making a puck which produced ZERO airspace in front of it would be the preferred direction here. Am I wrong?

 

I think you're right. The recess on those pucks is so small that it doesn't seem make a difference, though. The position and size of the gas ports makes a much bigger difference. A truly zero airspace puck might be more sensitive to fouling. The solution to that could be adding more vents to the rear of the puck chamber. Stock Saigas already have that one vent which is only uncovered briefly when the puck has traveled full aft. Add a couple more to help the carbon get blown out.

 

Now I don't mean to put down the recessed pucks like the KA version. They work. The recess looks cool and provides somewhere for fouling to go that doesn't jam the gun. Good enough.

[kingjoey 5]

The objective of the recess is to increase the initial volume of the cylinder. When the shotwad passes the gas port, it has a fraction of a second to pressurize the cylinder. As the tappet moves rearward, the volume of the cylinder increases and the pressure decreases. By increasing the initial volume slightly, you start off with a larger volume of gas at the same or nearly the same initial pressure, as the tappet moves rearward and the volume increases, the pressure doesn't decrease as much or as rapidly which creates a stronger cycling impulse. Pressure is inversely related to volume, so if volume doubles then pressure halves. Hypothetically speaking, if the OEM setup starts with 1 unit of volume at 500psi and ends with 5 units of volume at 100psi With a recessed puck such as the KA-SG01A then by adding 20% (not the actual figure) more initial volume at comparable pressure you would have 1.2 units at 500psi initially and would end with 5.2 units at 115.4 psi. This also makes the pressure curve over that time slightly higher and wider as well. Too much initial volume and the gas system won't have enough time to pressurize. The difficulty was in finding the right volume to improve cycling on most units without overboosting the cycling either. Also, by manipulating the volume we get a more "average" operation from the S-12 system, instead of the tempermental results that often occur with modding the gas ports to improve cycling of particular ammunition loads. We also designed the relief so that there wasn't anything directly in front of the ports when the tappet is fully forward, this reduces the amount of fouling that accumulates along the edge of the tappet and the walls of the cylinder. With the KA-SG01 setup, it uses the propellant coming through the gas port to 'blast' the edge of the tappet and dislodge solids. There isn't much venting for the S-12 system, so solids in the gas system are inevitable. Our goal was to keep the solids small and moving freely in front of the tappet, rather than allowing bulk to build up on the walls and on the sides of the tappet. Allowing crud to build up on the sides of the tappet increases the drag of the tappet and hinders cycling, it doesn't matter if the tappet has "teeth", saw blades, or any other gimmick, the key to keeping the tappet moving freely is to keep the bearing surfaces clear of anything that will cause dragging/friction, that is why we designed to face of the tappet with the recess and with a sharp leading edge and ever so slightly larger in diameter than the average S-12 tappet (everything on S-12's has to be designed around an 'average' dimension pretty much since the Russkies' tolerances are substantial) . By keeping the crud out of the sides of the tappet it will run smoother and longer. It was a pretty "common sense" solution from an engineering perspective, but took a lot of R&D to refine.

[zenmetsu 17]

Thanks for the explanation. I understand the pressure vs. volume argument, I went to ASU for chem. engineering and had more than my fair share of time with various gas equations. I won't get into a huge argument on this one because you apparently put in some R&D time. The equations and modeling mean nothing if the product cannot perform. People have given the KA tappet good reviews and even claim that it allows them to cycle that Wallyworld Winchester wannabe shells, but I believe that the tappet is excelling due to something other than initial gas volume.

 

I realize now that my initial argument was incorrect for the most part. The pressure in the gas tube and the pressure in the bore should be more or less equal as I am sure that equalization happens almost immediately after the shotwad passes the ports. You are looking at pressure vs. volume at two points: first when the shotwad clears the gas ports and second when the round leaves the muzzle (or the tappet strikes the stop, whichever is first). The volume change between these two points is easily dominated by the increased volume within the bore as the shotwad moves forward. The gas tube's volume might as well be zero.

 

What I can see happening is that the tappet undergoes acceleration due to the pressure in front of the tappet. The pressure is constantly decreasing as the load travels down the bore and the tappet moves rearward, but I am fairly certain that acceleration remains positive until the tappet strikes the stop within the gas tube. If the tappet is thinner (front to back), then it will be allowed to accelerate over a longer period of time before striking the stop. Longer period of acceleration = higher speed, thus the tappet imparts a greater amount of kinetic energy to the bolt carrier.

 

I agree with you 100% though regarding making the tappet with a larger diameter to prevent fouling, and using a sharp leading edge to try to keep the fouling up front against the gas plug.

 

I might just pick up one of your tappets to try out. I try to support AZ businesses whenever I can. Besides, I don't really care WHY something works, as long as it does work.

[kingjoey 5]

The tappet isn't going to open the breech until the pressure has dropped. The gas system will pressurize and start to move the carrier, but the actual gas impulse on the tappet is generally around .002 seconds. Basically, the shot is fired, the wad and payload leave the barrel, then the action cycles. By allowing a slightly larger amount of gas to be drawn off, it widens the impulse curve and higher across the timeline. This doesn't increase the initial amount of pressure, just the volume. Acceleration of the tappet is still dictated by the force that the gas pressure exherts against the cross-section of the puck (not the total surface area such as the angled surfaces), the only difference is that the volume increases proportionately slower due to the increased initial volume. Our tappet is the same thickness as the OEM piston, around .588". Running a thinner piston would allow the tappet to reach higher speeds before contacting the op-rod but would basically hammer the tappet and the op-rod causing deformation/damage to both parts.

[E-TAC 47]

Now think about this for just a moment. Increasing the volume of the gas chamber actually works against you. Theoretically speaking, if you had a 10 foot gas tube with the puck at the end, MOST of the gas being vented into the tube would go to work compressing the pre-existing gas (air) in the tube. The amount of work being done on the puck would be greatly minimized.

 

If anything, I would suspect that making a puck which produced ZERO airspace in front of it would be the preferred direction here. Am I wrong?

 

I think you're right. The recess on those pucks is so small that it doesn't seem make a difference, though. The position and size of the gas ports makes a much bigger difference. A truly zero airspace puck might be more sensitive to fouling. The solution to that could be adding more vents to the rear of the puck chamber. Stock Saigas already have that one vent which is only uncovered briefly when the puck has traveled full aft. Add a couple more to help the carbon get blown out.

 

Now I don't mean to put down the recessed pucks like the KA version. They work. The recess looks cool and provides somewhere for fouling to go that doesn't jam the gun. Good enough.

 

Your correct, the recess gives more space for the crud...But our Magnum TwisterPuc is the only one that will blast the crud out the stock exhaust port. So as time passes by and more start to use the TwisterPuc the votes will start to favor a Twist....

 

Aloha

[zenmetsu 17]

Fair enough. I was under the assumption that the operating rod head and tappet were in contact when the bolt was forward, thus any movement of the tappet would result in a movement of the carrier and there would be no hammering of parts. Now that I listen, i can tell that the tappet is free moving even when the bolt is closed by rocking the gun back and forth.

 

Hard to believe that the tappet can hold enough kinetic energy to cycle the action in this manner. Any idea as to the approximate velocity of the tappet when it contacts the operating rod? This is all so fascinating.

[zenmetsu 17]

Your correct, the recess gives more space for the crud...But our Magnum TwisterPuc is the only one that will blast the crud out the stock exhaust port. So as time passes by and more start to use the TwisterPuc the votes will start to favor a Twist....

 

Aloha

 

OI!! This sounds like a duel! Only one way to settle this... TORTURE TEST!!!

 

I guess that I could buy one of each and put them to the test... see what allows me to cycle the weaker loads, and see how many rounds I can fire before fouling of the gas system becomes an issue. Hell, i can even measure the amount of residue in the gas tube after 500 rounds on each tappet.

 

This will give me a good reason to dust off my clay launcher...

[kingjoey 5]

Fair enough. I was under the assumption that the operating rod head and tappet were in contact when the bolt was forward, thus any movement of the tappet would result in a movement of the carrier and there would be no hammering of parts. Now that I listen, i can tell that the tappet is free moving even when the bolt is closed by rocking the gun back and forth.

 

Hard to believe that the tappet can hold enough kinetic energy to cycle the action in this manner. Any idea as to the approximate velocity of the tappet when it contacts the operating rod? This is all so fascinating.

 

 

There is a little bit of room in there, but obviously with that much force behind it, any additional space is going to greatly increase the speed of the tappet before it contacts the op-rod. Basically, it is giving the op-rod a very hard and very quick shove which is enough to have the bolt cycle all the way to the rear. The speed of the tappet isn't very fast, but its acceleration is substantial. Look at it as a car that has a max speed of 30mph but can go 0-30 in 1/4 second, not necessarily "fast", but quicker than anything else on the road It can accelerate the bolt carrier quickly enough in the short amount of travel that it has that it takes a spring and a few inches of travel (and usually a rear trunnion) to stop it. I know that any time we develop a piston or op-rod it requires a lot of testing to ensure that we get the optimal temper for the metal, if it is too hard it can crack/break, if it is too soft it will bend/mushroom. On our tappets we wanted extreme hardness to reduce fouling adhesion and wear, but to get that without brittleness we had to use some oddball alloys such as 4340CM which is very impact resistant.

[kingjoey 5]

Your correct, the recess gives more space for the crud...But our Magnum TwisterPuc is the only one that will blast the crud out the stock exhaust port. So as time passes by and more start to use the TwisterPuc the votes will start to favor a Twist....

 

Aloha

 

OI!! This sounds like a duel! Only one way to settle this... TORTURE TEST!!!

 

I guess that I could buy one of each and put them to the test... see what allows me to cycle the weaker loads, and see how many rounds I can fire before fouling of the gas system becomes an issue. Hell, i can even measure the amount of residue in the gas tube after 500 rounds on each tappet.

 

This will give me a good reason to dust off my clay launcher...

 

 

If you want to torture test one I'll send you a KA-SG01A at no charge.

[zenmetsu 17]

Your correct, the recess gives more space for the crud...But our Magnum TwisterPuc is the only one that will blast the crud out the stock exhaust port. So as time passes by and more start to use the TwisterPuc the votes will start to favor a Twist....

 

Aloha

 

OI!! This sounds like a duel! Only one way to settle this... TORTURE TEST!!!

 

I guess that I could buy one of each and put them to the test... see what allows me to cycle the weaker loads, and see how many rounds I can fire before fouling of the gas system becomes an issue. Hell, i can even measure the amount of residue in the gas tube after 500 rounds on each tappet.

 

This will give me a good reason to dust off my clay launcher...

If you want to torture test one I'll send you a KA-SG01A at no charge.

 

Let me get some baseline data with the stock tappet first. I'll probably end up buying one of these anyways since I like to support the locals. 500 rounds is probably excessive per tappet, but we'll see. I'll toss my address your way once i get the baseline data recorded.

[SaigaNoobie 66]

My buddy ran 1500 rounds through his S-12 over a week with the KA puck in there.

 

500 rds isn't excessive, it's just breaking it in.

 

I say 1000rds each! =D

[Crusader 64]

Your correct, the recess gives more space for the crud...But our Magnum TwisterPuc is the only one that will blast the crud out the stock exhaust port. So as time passes by and more start to use the TwisterPuc the votes will start to favor a Twist....

 

Aloha

 

OI!! This sounds like a duel! Only one way to settle this... TORTURE TEST!!!

 

I guess that I could buy one of each and put them to the test... see what allows me to cycle the weaker loads, and see how many rounds I can fire before fouling of the gas system becomes an issue. Hell, i can even measure the amount of residue in the gas tube after 500 rounds on each tappet.

 

This will give me a good reason to dust off my clay launcher...

 

 

If you want to torture test one I'll send you a KA-SG01A at no charge.

 

Jammer. Could you also send Zenmetsu a twister puck, at no charge, so he can test it against the KA-SG01A?

 

Zenmetsu. You are going to use lots of ammo. Are you up to it?

[zenmetsu 17]

Your correct, the recess gives more space for the crud...But our Magnum TwisterPuc is the only one that will blast the crud out the stock exhaust port. So as time passes by and more start to use the TwisterPuc the votes will start to favor a Twist....

 

Aloha

 

OI!! This sounds like a duel! Only one way to settle this... TORTURE TEST!!!

 

I guess that I could buy one of each and put them to the test... see what allows me to cycle the weaker loads, and see how many rounds I can fire before fouling of the gas system becomes an issue. Hell, i can even measure the amount of residue in the gas tube after 500 rounds on each tappet.

 

This will give me a good reason to dust off my clay launcher...

 

 

If you want to torture test one I'll send you a KA-SG01A at no charge.

 

Jammer. Could you also send Zenmetsu a twister puck, at no charge, so he can test it against the KA-SG01A?

 

Zenmetsu. You are going to use lots of ammo. Are you up to it?

 

I am totally up for it. I wanna get some of it on video though, and I lack a camcorder. Maybe my friend has one and we can go filming in the desert or at least a little bit on the range.

 

12ga ammo is cheap. The task is to have fun doing the testing, and not just shoot for the sake of shooting. If I am out shooting sporting clays, time will pass much faster. If my friend's saiga-12 ships this week, we can actually test in two different guns just to be on the safe side.

 

The twister-puc looks pretty cool though, I give credit for that. I am all about function and utility though. Which ever tappet works best is going to end up going into my firearm.

 

I will probably wait until after my conversion to do the tests though (so maybe first week of september). Not a good test to have the gun in different states between the individual runs. In addition, I want to use hi-cap mags to speed up testing, and I need to be legal for this. I would be OK using the KA and twister-puc, but the moment i put the russkie one in there, i am up to 11 non-US parts. Club-Fed, nothx.

Edited August 18, 2009 by zenmetsu

[waltham_41 52]

Anyone else have an alliance armament puck?

 

I bought my S12 before finding this forum, and didn't know they were the bad guys. They tried to sell me a drum at the same time but I didn't have the money at the time.

 

Cant say anything bad about the puck, it works fine, and is easy to clean when it gets dirty.

 

It sits right above my MD20 Drum. Talk about a shotty with conflicting mojo LOL

[aresv 49]

Thanks KA! I think I see where you're coming from. Sort of the pneumatic version of impedance matching.

[kingjoey 5]

Sort of the pneumatic version of impedance matching.

 

Not exactly, but thanks for the EE flashback

[goingpro 2]

this is a small upgrade and i will be adding a KA puck soon.

[zenmetsu 17]

My gun FTE'd 3 out of 200 rounds of the cheap winchester birdshot. With it hovering just on the functional side, I feel that I can get some useful numbers when comparing these pucks.

 

Still waiting for my conversion parts to come in. I should have them all next week and be finished with the conversion by next weekend. I will try to start my test with the factory puck and put 500 rounds through it this coming Saturday.

[camon 233]

My gun FTE'd 3 out of 200 rounds of the cheap winchester birdshot. With it hovering just on the functional side, I feel that I can get some useful numbers when comparing these pucks.

 

Still waiting for my conversion parts to come in. I should have them all next week and be finished with the conversion by next weekend. I will try to start my test with the factory puck and put 500 rounds through it this coming Saturday.

 

This coming Saturday?? As in the 29th???

 

If so, I hate you.

[zenmetsu 17]

Still waiting on my trigger group and trigger guard, so I unless I get them Friday, conversion will happen next week. I am in no rush. I prefer to "do shit right the first time"... ya know?

[bigj480 203]

I'm definitely interested in a comparison. I think you should use the dirtiest/lightest load that will cycle your gun. That will make a malfunction likely to occur int the 500-1000 rounds you will likely shoot. Remember to keep the variables to a minimum. Two internally identical guns with a similar number of rounds through them, clean and lube both the in the same manner before the comparison and obviously the same ammo. I'm not sure that a new gun is the best one to use, though.

[kingjoey 5]

You'd get more accurate results using the same gun but starting with it completely clean each time. With the wide fluctuation in tolerances and QC, you'd be hard-pressed to find two S-12's that were close enough to give an accurate test.

[shades_of_grey 1,092]

Mine works fine with the stock one, so I dont see a reason to change it.

 

+1

 

I kept the OEM part and instead bought a Gunfixr's Gas Plug, (which gives you much more control and is a more important part of the gas system). It's worked great. I have no reason to buy an aftermarket puck, (no performance or compliance issues).

Edited August 31, 2009 by post-apocalyptic

[Azkamidaka 26]

I really really want the twister puck to work, it seems like a great idea but I would like to see some supporting data.

 

I just bought a Tromix one for 922r.

Edited September 1, 2009 by Azkamidaka

[Ronswin 26]

I have been using the KA tappet for some months now and have noticed that the Saiga-12 cycles a bit more reliably with Wal-mart Remington/ Federal light birdshot loads and the gas cylinder does have a lot less carbon fouling. I've recently added a Gunfixer gas plug and I think the KA tappet plus Nate's adjustable plug work well together.

[ck43001 12]

I really really want the twister puck to work, it seems like a great idea but I would like to see some supporting data.

 

 

IPSC_GUY range report

 

 

Also, pm sent to zenmetsu.

[Rangerfan1423 2]

Looks like he hasnt used any other tappet. I think members are looking for more of a comparison...as I am also.

[zenmetsu 17]

You'd get more accurate results using the same gun but starting with it completely clean each time. With the wide fluctuation in tolerances and QC, you'd be hard-pressed to find two S-12's that were close enough to give an accurate test.

 

I meant that we would test all 3 pucks in both guns... so you would have a total of 6 shooting sessions. It may be that the KA puck works better in one gun than the other, or the Twister may be the only one that is better, but only in one of the two guns... who knows..

 

More data = better test. By no means was I implying that I would test the twister puck in one gun and the KA in another... that would be a completely invalid test.

[E-TAC 47]

New manufacture direct pricing for our line TwisterPucs $25 shipped!!! This is a limited time offer.

[BobAsh 582]

Until somebody can show me an ATF letter stating that the puck is the countable part I'm not banking on it. Yes, theoretically it should be, but no one has ever asked for a official determination from them. They could just as easily be counting the carrier extension as the piston as in a normal AK, since they are not counting it as an op rod.

Well until the BATFE makes a determination on which one they count, non of us can be sure. And yes, they have been asked but no definative answer given. So life goes on. When is the last time the BATFE enforced 922R? With only 4 parts to replace to be "compliant", the puck/tappet should be of little concern.

My modestly converted S-12 has 7 counted U.S. parts not including the puck and pistol grip.

I think what should be determined is what these damn things are....pucks....pistons......or tappets??

 

Allow me to settle this for you.

 

Tony has an ATF letter stating that on the Saiga shotgun the "gas piston" is the puck, not the carrier extension.