Reduced recoil theory

[empirepb 0]

After watching a video by FPS russia,

 

http://www.youtube.com/watch?v=tD0PKDGlwiw

 

(fast forward to 2:52) I figured why couldn't the same principle of the AA12 recoil system apply to the Saiga 12? I found this video AA12 Disassembly so I could get a better understanding of how the system worked and it didn't seem too complex. So the principle would require a longer but slightly weaker spring to replace the original, as well as running the spring further through the carrier to force a slower cycling time but to achieve less recoil.

Does my theory work? I'm sure this isn't the first time something like this has been thought of and maybe the approx. 3" of additonal spring length wouldn't warrant all the work to achieve that bit of reduction. I doubt everyone has an extra carrier laying around to test this so I figured this would be a higher risk idea to have some brains think about first.

[Nephilim7 107]

^{I am NO EXPERT!!! But, there are a few problems with this idea. Maybe others will point out other problems or disagree with me...}

 

^{1. The spring would pass through the cut out area you have shown in the pic. I believe this area is there to clearance spent hull ejection.}

 

^{2. The longer spring you suggest better be made of REALLY thin wire diameter steel. More coils means shorter distance traveled before coils touch each other and spring becomes solid.}

 

^{I also believe this long-recoil setup would create less of a tolerance window of useable pressures. Therefore, cycling issues would insue. (finicky with ammo type) Isn't that one of the things the AA12 is known for? This could be fixed with some type of self-throttling spring system... Translation lots of moving parts and extra weight.}

 

^{This is all off the cuff, so feel free to correct me.}

[obiwanbonjovi 337]

the length of the spring has nothing to do with it, it is the length of carrier travel. You are not increasing carrier travel, the carrier will still come to a dead stop at rear.

[Lone Star Arms 2,047]

First off, I just want to make clear that we are discussing recoil here, and not building a full auto S12 - which without the proper licensing will get you a guaranteed one way trip to club fed.

 

Putting a weaker spring in the gun isn't going to do anything significant to reduce recoil. Use a weaker spring with full powered ammo, and you'll just beat the crap out of your bolt carrier and rear trunion, and will end up with more felt recoil because beyond beating the crap out of your rear trunion, and bolt carrier, the gun will also beat the crap out of the shooter.

 

I've never seen the AA12 run anything but low base ammo which is fairly low recoil to start with. I sincerely doubt the S12 FA SBS build in the video will cycle anything but full powered shells. The cyclic rates of the guns are also vastly different. An FA Saiga 12 cycles at around 600 rounds per minute. The AA12 has a cyclic rate of around 250 (which is well within the capabilities of a skilled user with a semi auto S12).

 

The AA12s relatively slow cyclic rate, heavier weight (14 lbs.), and use of lower powered shells, all play a role in "reduced recoil". There is plenty of room in the AA12s huge cartoonish plastic casing for various odds and ends to reduce felt recoil as well.

 

We build reduced recoil guns for our clients every day that will run circles around both the poorly executed FA S12 used in the FPS Russia video, and the huge, cumbersome, and relatively slow AA12.

 

http://youtu.be/CYfJlIMHhkE

[evlblkwpnz 3,418]

That would have to be a really small diameter spring because the carrier needs to stay thin in that area to allow room for the hulls to eject. Great idea, but not for the s12....

[rs51085 136]

all i can say is wow. that FA S12 in your video Mike is awesome. it looks like he is shooting a full auto .223 instead of a 12 gauge. If FPS Russia was shooting one of your guns i think he would have a different opinion of the S12. But that is ok because he is not worthy of such a fine weapon!

[empirepb 0]

the length of the spring has nothing to do with it, it is the length of carrier travel. You are not increasing carrier travel, the carrier will still come to a dead stop at rear.

 

This is what I had a feeling would dismiss my idea. So unless the carrier could travel that extended length of spring it won't matter, oh well, thanks for clarifying the physics in my head.

[Lone Star Arms 2,047]

all i can say is wow. that FA S12 in your video Mike is awesome. it looks like he is shooting a full auto .223 instead of a 12 gauge. If FPS Russia was shooting one of your guns i think he would have a different opinion of the S12. But that is ok because he is not worthy of such a fine weapon!

 

Rogers -Thanks, but It isn't FA. It is a Semi Auto, LSA low recoil Signcutter high performance build. The gun itself is exceptionally fast and very controllable, and Joe just happens to be exceptionally fast and skilled on the trigger. I only know a couple of guys who can shoot SA that fast from the shoulder, and Joe is one of them. Will had a guy on SOG a couple of seasons ago who could run an SA trigger that fast. Its pretty rare.

 

empirepb - AKs typically use a mechanical rate reducer to to limit the rate of fire.

[corbin 621]

I've looked at recoil reducing stocks (like a Mako GL Shock for instance). However, I wonder how much recoil you can have the stock absorb until it becomes a situation where it robs the weapon of the force needed to reliably cycle. I just stick with a Limbsaver pad and a buffer (yes, a buffer in my Saiga 12... OH NO!)

Edited September 18, 2012 by Corbin

[Salt1219 176]

@Mike

Would you mind sharing some of the ways you reduce recoil on your saiga builds?

[Black Russian 1]

First off, I just want to make clear that we are discussing recoil here, and not building a full auto S12 - which without the proper licensing will get you a guaranteed one way trip to club fed.

 

Putting a weaker spring in the gun isn't going to do anything significant to reduce recoil. Use a weaker spring with full powered ammo, and you'll just beat the crap out of your bolt carrier and rear trunion, and will end up with more felt recoil because beyond beating the crap out of your rear trunion, and bolt carrier, the gun will also beat the crap out of the shooter.

 

I've never seen the AA12 run anything but low base ammo which is fairly low recoil to start with. I sincerely doubt the S12 FA SBS build in the video will cycle anything but full powered shells. The cyclic rates of the guns are also vastly different. An FA Saiga 12 cycles at around 600 rounds per minute. The AA12 has a cyclic rate of around 250 (which is well within the capabilities of a skilled user with a semi auto S12).

 

The AA12s relatively slow cyclic rate, heavier weight (14 lbs.), and use of lower powered shells, all play a role in "reduced recoil". There is plenty of room in the AA12s huge cartoonish plastic casing for various odds and ends to reduce felt recoil as well.

 

We build reduced recoil guns for our clients every day that will run circles around both the poorly executed FA S12 used in the FPS Russia video, and the huge, cumbersome, and relatively slow AA12.

 

http://youtu.be/CYfJlIMHhkE

 

So what would you recommend to reduce recoil a reduced recoil buttstock?

[Lone Star Arms 2,047]

@Mike

Would you mind sharing some of the ways you reduce recoil on your saiga builds?

 

Not at all. Recoil reduction on both ends of the gun, several years of R&D and hundreds of hours of eating dust, and shoveling up shells out at the range testing and refining the design.

 

Rumore did a brilliant job when he came up with the monster brake. Screw one on the end of an S12 barrel and you'll experience a tremendous reduction in felt recoil. We also use Mesa Tactical Enidine "Shot Shock" technology at the other end of the gun. What goes on in between, is a significant amount of refinement in tuning and balancing the firearm to take full advantage of of the recoil reduction while functioning reliably with a full range of ammunition.

 

[Cobra 76 two 2,677]

I use mercury for one.....

A spring or shock absorber type stock tube in an M-4 style stock also does wonders.

 

@ Corbin.... A good friend of mine finally got his paperwork back last week and we got to have some fun with his Saiga. We were running an 11" S-12 this weekend with a normal length gas system (modified ports and gas block of course...), all my usual performance upgrades, and it ran flawlessly on 1200 FPS Federal 7.5 and 8 shot. Cycled 00 buck like a champ of course on the open setting of the V plug. Did great with the regular factory puck and nothing screwed on the barrel. All that with a Kicklite stock AND a recoil buffer.

First test with 00 buck (before deciding to cut another inch off from 12 where it was because it cycled low brass ok without a choke) Using factory stock with built in mercury reducer... just for testing purposes...

 

The resulting shit eating grin of course ...LOL.

 

With the 1200 FPS Federal that night on 11", the recoil reducing stock, and naked barrel.

And of course the obligatory night shot with high brass...

 

 

[Salt1219 176]

Thanks mike and cobra, i will look into all that.

[Squishy 1,149]

Mike is there any difference between the Mesa Tactical Enidine Shot Shock and a plain Enidine Shot Shock?

[Lone Star Arms 2,047]

Mike is there any difference between the Mesa Tactical Enidine Shot Shock and a plain Enidine Shot Shock?

 

No. I believe Mesa Tactical is the manufacturer, and "Enidine" and "Shot Shock" are trade names.

[gunfun 3,931]

Some of the Russian guys (Sergii IIRC) had another interesting method. They used an AR type stock and buffer tube with an aluminum chunk that could slide forward and prutrude under the rear trunion so that the bolt carrier hit it in the last 3/8" or so of stroke. This chunk of aluminum could take the energy of the bolt and recoil down the buffer tube against a spring. So in effect the mass of the bolt got to decelerate over a longer distance. It is supplemental to the standard operating system and does not require changing the mainspring.

 

I've thought of a way that this could be achieved even with a folding stock setup. With the stock folded, it would operate just like normal with the stock in line with the carrier it would take the energy.

 

Progressive springs are a simpler worthwhile idea to try out. They work well in many other applications.

 

I can say on my gun that 1" kickeez + C&H mercury tube (as Cobra plugged above) + Custom muzzle brake is a very effective combo without any pogo stick feeling. It mounts up as solid as anything and people always comment with surprise about how softly it shoots.

[dgyver 13]

Has anyone tried a multiple spring design, as used on many semi-auto pistols? I use one on my Beretta which really helped and I know many 1911's use them too.

[TORKIT 20]

I already have another topic on this but I'll chime in, I put 2 performance springs from CSS on mine, replaced both stock springs, now it has half the recoil and NO FTE with bulk low brass.

[filthygovemploye 64]

this thread is full of win!!!

 

 

lots o great thinkin, great guns, and good times. needs more boobies though!!!!

[PapaZorro 401]

Some of the Russian guys (Sergii IIRC) had another interesting method. They used an AR type stock and buffer tube with an aluminum chunk that could slide forward and prutrude under the rear trunion so that the bolt carrier hit it in the last 3/8" or so of stroke. This chunk of aluminum could take the energy of the bolt and recoil down the buffer tube against a spring. So in effect the mass of the bolt got to decelerate over a longer distance. It is supplemental to the standard operating system and does not require changing the mainspring.

 

I've thought of a way that this could be achieved even with a folding stock setup. With the stock folded, it would operate just like normal with the stock in line with the carrier it would take the energy.

 

Progressive springs are a simpler worthwhile idea to try out. They work well in many other applications.

 

I can say on my gun that 1" kickeez + C&H mercury tube (as Cobra plugged above) + Custom muzzle brake is a very effective combo without any pogo stick feeling. It mounts up as solid as anything and people always comment with surprise about how softly it shoots.

 

Sergiis Vepr buffer you've mentioned is not Aluminum, it's made from Steel and was suggested to AK systems by Vsevolod Ilyn and was made in cooperation with Chief Constructor of Molot Sergey Urzhumtsev on the Ilyns Vepr-12 (VPO206) as a part of complex for recoil reduction, that included modified by Ilyn Polygon muzzle brake, buffer with spring in the buffer tube and grind-to-fit KICK-EEZ butt pad for Magpul CTR, later Ilyn change Polygon muzzle brake, designed by Efimov, to his own design muzzle brake, now well known as Molot GK-01. Ilyns Vepr-12 was the first from VPO-206 model for IPSC.

 

Picture of Ilyn and his VPO-206, the first Vepr-12 with buffer, modified gas block, steel magwell, knob safety, RSA trigger group, Picatinni instead of rear sight, finger guard + Polygon muzzle brake modified by Ilyn, RPK lower handguard without rails, modified Saiga-12 mag.

 

 

 

Now Ilyn cooperate with IZMASH and switched from Vepr-12 to Saiga-12, so soon we can see GK-01 made by IZMASH . Pic of Ilyn and IZMASH custom made Saiga-12 with Ilyns Muzle brake GK-01.

 

 

Close up pic of buffer on Vepr-12, VPO-205-01 CE.

 

 

 

 

Now Molot use buffer with spring not only on their shotguns but also on their rifles with non folding AR-type stocks such on Antons' Vepr 7.62x39 on the following pic.

 

 

 

 

 

PS. Limbsaver promised to made but pad this year for Magpul CTR.

 

IMHO Limbsaver but pad + GK-01 is one of the best suggestion for recoil reduction that Saiga-12/Vepr-12 owner can do himself for his shotgun + buffer with spring that oner could not do:( without Molot/IZHMASH.

Edited October 7, 2012 by PapaZorro

[gunfun 3,931]

^^That's the one. Using a system like Newton's cradle, I think a hinged AR stock could have a slight protrusion that would press against that round part when extended, thus transferring energy. The 'transfer link' could also be a fat slug UHMW or similar to absorb even more shock.

 

This is essentially the same theory as the mercury systems, except using solid weights and springs, rather than more dense liquid weight and compressed gas to return with a valved delay to eliminate perceivable rebound. Obviously with either design, the longer the track which the mass can decelerate in, the less recoil would be felt.

 

There was an american system on the market a while ago called "Dead Mule" that is similar to the one PZ linked, with the exception that the energy from the bolt is not directly transferred into the buffer weight.

 

IMO, a lighter mass moving a longer distance is the optimum method, and don't make the bolt spring dependant on the buffer system for function.

[shoot2thrillu 10]

I already have another topic on this but I'll chime in, I put 2 performance springs from CSS on mine, replaced both stock springs, now it has half the recoil and NO FTE with bulk low brass.

 

i did that too and half the recoil is a understatement. and if anyone else trys this make sure you polish your bolt carrier hammer and bolt down good or your gonna feel where its hitting. runs so smooth now its almost scary