How weight effects cycling

[6500rpm 670]

Slightly off topic, but since Mike mentioned reducing the volume with the V plug-could any performance gains be had by screwing out the carrier extension to the point where it's almost in contact with the plug face. Doesn't actually do anything in terms of the total volume of the chamber, but it would in effect give the puck a longer stroke. I can see it might have a negative effect as crap builds in the gas block. For those with Tromix, Red Jacket, R and R guns-do these builders also induce free travel in the puck like the factory gun?

Could be interesting if you could post some specs in terms of the puck face seated against the carrier extension to the face of the gas block.

 

My 3 using the same puck,

2001=.767"

2008=.766"

2008=.776"

Edited February 6, 2011 by 6500rpm

[The_Caged_Bird 474]

Slightly off topic, but since Mike mentioned reducing the volume with the V plug-could any performance gains be had by screwing out the carrier extension to the point where it's almost in contact with the plug face. Doesn't actually do anything in terms of the total volume of the chamber, but it would in effect give the puck a longer stroke. I can see it might have a negative effect as crap builds in the gas block. For those with Tromix, Red Jacket, R and R guns-do these builders also induce free travel in the puck like the factory gun? Could be interesting if you could post some specs in terms of the puck face seated against the carrier extension to the face of the gas block.

 

I would imagine that if you screwed out the carrier extension then you would be putting all of the cycling forces on the threads of the bolt carrier rather than the bolt carrier itself.

 

Sounds like a quick way to break a bolt carrier, I definitely would NOT do that! :dollar:

[6500rpm 670]

Thread out and re-pin just like any other AK. I actually just did a Bulgarian AK 74 build that was the first I found that if I didn't have enough play in the piston it locked up the carrier. I think broken carriers would be the least worry , I'm just curious as to why puck free travel is built into the factory guns. Quick and dirty measurement with factory puck and plug only looks to have about .042" free travel on average which isn't a lot.

Edited February 6, 2011 by 6500rpm

[MikeD 541]

Slightly off topic, but since Mike mentioned reducing the volume with the V plug-could any performance gains be had by screwing out the carrier extension to the point where it's almost in contact with the plug face. Doesn't actually do anything in terms of the total volume of the chamber, but it would in effect give the puck a longer stroke. I can see it might have a negative effect as crap builds in the gas block. For those with Tromix, Red Jacket, R and R guns-do these builders also induce free travel in the puck like the factory gun?

Could be interesting if you could post some specs in terms of the puck face seated against the carrier extension to the face of the gas block.

 

My 3 using the same puck,

2001=.767"

2008=.766"

2008=.776"

 

I believe you are dead on. This is something we just stumbled upon ourselves resently. We have samples of guns that are varing by .050 or so in difference from one to the other. This doesn't sound like much but when you consider that the travel is just over .500" you are loosing roughly 10%. Now factor in that this 10% lose is at the front of the pressure which means you will be losing from the strongest end of the stroke. Continue to factor in that this also increase the size of the gas chamber as well as you mentioned if you are losing stroke. Before the gas chamber is pressurized the piston has been rested against the operating rod so the volume increase is in there in the begining and delays pressurization.. I am 99.9% sure this is a good chunk of energy loss. We haven't been able to confirm yet though. But it is a much anticipated round of testing. We can say the guns we have with less distance have been hotter running guns from the start... I don't believe anyone is checking this because if they were we surly would be hearing about it in advertisment of services or work.

[pedal2alloy 206]

Slightly off topic, but since Mike mentioned reducing the volume with the V plug-could any performance gains be had by screwing out the carrier extension to the point where it's almost in contact with the plug face. Doesn't actually do anything in terms of the total volume of the chamber, but it would in effect give the puck a longer stroke. I can see it might have a negative effect as crap builds in the gas block. For those with Tromix, Red Jacket, R and R guns-do these builders also induce free travel in the puck like the factory gun?

Could be interesting if you could post some specs in terms of the puck face seated against the carrier extension to the face of the gas block.

 

My 3 using the same puck,

2001=.767"

2008=.766"

2008=.776"

 

I believe you are dead on. This is something we just stumbled upon ourselves resently. We have samples of guns that are varing by .050 or so in difference from one to the other. This doesn't sound like much but when you consider that the travel is just over .500" you are loosing roughly 10%. Now factor in that this 10% lose is at the front of the pressure which means you will be losing from the strongest end of the stroke. Continue to factor in that this also increase the size of the gas chamber as well as you mentioned if you are losing stroke. Before the gas chamber is pressurized the piston has been rested against the operating rod so the volume increase is in there in the begining and delays pressurization.. I am 99.9% sure this is a good chunk of energy loss. We haven't been able to confirm yet though. But it is a much anticipated round of testing. We can say the guns we have with less distance have been hotter running guns from the start... I don't believe anyone is checking this because if they were we surly would be hearing about it in advertisment of services or work.

 

Maybe that would be another way to tune the guns, which is to make pucks of varying depths.

[The_Caged_Bird 474]

Thread out and re-pin just like any other AK. I actually just did a Bulgarian AK 74 build that was the first I found that if I didn't have enough play in the piston it locked up the carrier. I think broken carriers would be the least worry , I'm just curious as to why puck free travel is built into the factory guns. Quick and dirty measurement with factory puck and plug only looks to have about .042" free travel on average which isn't a lot.

 

 

Ah, I mis-read that then...

 

Slightly off topic, but since Mike mentioned reducing the volume with the V plug-could any performance gains be had by screwing out the carrier extension to the point where it's almost in contact with the plug face. Doesn't actually do anything in terms of the total volume of the chamber, but it would in effect give the puck a longer stroke. I can see it might have a negative effect as crap builds in the gas block. For those with Tromix, Red Jacket, R and R guns-do these builders also induce free travel in the puck like the factory gun?

Could be interesting if you could post some specs in terms of the puck face seated against the carrier extension to the face of the gas block.

 

My 3 using the same puck,

2001=.767"

2008=.766"

2008=.776"

 

I believe you are dead on. This is something we just stumbled upon ourselves resently. We have samples of guns that are varing by .050 or so in difference from one to the other. This doesn't sound like much but when you consider that the travel is just over .500" you are loosing roughly 10%. Now factor in that this 10% lose is at the front of the pressure which means you will be losing from the strongest end of the stroke. Continue to factor in that this also increase the size of the gas chamber as well as you mentioned if you are losing stroke. Before the gas chamber is pressurized the piston has been rested against the operating rod so the volume increase is in there in the begining and delays pressurization.. I am 99.9% sure this is a good chunk of energy loss. We haven't been able to confirm yet though. But it is a much anticipated round of testing. We can say the guns we have with less distance have been hotter running guns from the start... I don't believe anyone is checking this because if they were we surly would be hearing about it in advertisment of services or work.

 

Maybe that would be another way to tune the guns, which is to make pucks of varying depths.

 

 

Hmmm, you might want to patent that design...

[evlblkwpnz 3,418]

You would have no issues weather you stripped the Saiga 12 down to nothing or added 20 pounds of junk to it. As long as you securely shoulder the weapon it will cycle. The only thing that would impede this is if you let the weapon move rearward and absorb the recoil. ie; limpwristing, firing from the hip, etc.

+1

 

.... and soft buttpads will absorb much of the energy that would be better put to use cycling the action. I agree with KC. I think weight isn't much of a factor if you hold the weapon properly.

[Mephis 82]

Where weight matters is the bolt.

 

Just like the slide on a pistol. It will reduce recoil and allow you to cycle a hotter round the heavier the slide gets. Along with that, the heavier it is the harder it is to move, thus making it less likely to cycle weak ammo.

 

 

I'm not saying for anyone to start cutting their bolts up, just mentioning where the weight that matters is.

[Jdhonda810 29]

Where weight matters is the bolt.

 

Just like the slide on a pistol. It will reduce recoil and allow you to cycle a hotter round the heavier the slide gets. Along with that, the heavier it is the harder it is to move, thus making it less likely to cycle weak ammo.

 

 

I'm not saying for anyone to start cutting their bolts up, just mentioning where the weight that matters is.

 

So I had a question I PM'ed Cobra about referring to the new HEAVY duty op rod they are marketing and haven't received an answer yet. How will this affect cycling and reliability by adding the extra weight of the op rod?

[lbsrdi 1,078]

It seems to me that weight could be part of the reason people have such great results with the MD20. I know that the drum is well designed and well built with quality materials, Im just saying that the added weight some complain about may be helpful to cycling also, at least for hip firing.

[lbsrdi 1,078]

I don't use one, but I wonder how the use of a limbsaver pad would effect cycling. Going with the thinking that it is better to hold the stock firmly against your shoulder, it seems that it would have some effect, albeit very minimal. What do you think or what has been your experience?

Edited February 21, 2011 by King of the Hill

[pitt1720 0]

I would not think that weight would affect cycling however I have read other posts on here where people have stated that a change in hanguard or stock affected the cycling and I can't understand why?

[lbsrdi 1,078]

Mike explained it pretty well above.

[skiboatsp 111]

WRONG! If the weapon is truly functioning properly, you could fire it and it would function no matter how you hold/not hold the weapon. It is not blow-back operated, it is gas operated.

 

I've experimented with the way I hold mine since I opened up the ports. It doesn't matter, IF the weapon is functioning properly. If you have to shoulder the weapon hard or put the butt-stock up against a tree, your gun is NOT functioning properly (Mike D, this wasn't aimed at you, we know that you were doing that to test the strength of the front feed-lip of your drum). There is a big difference between functioning and functioning properly...

 

I will say though, that I shoulder the weapon hard to try to be nice to my shoulder, but it doesn't affect my shotgun's performance one bit.

Hey, let's get this straight. I put it against the tree because I'm a big puss. No, I put it against the tree to reduce the forces on the front mag catch. All of those videos of me firing off of a tree was with prototype mags of greatly reduced strength compared to production mags. I did it to keep them from coming apart and breaking, even then it didn't prevent it all the time.

 

The rest of this isn't pointed at you either but just some answers on the question.

 

Weight does matter. First, how a gun is held will affect the function of the gun regardless if it is gas operated. In theory if the gun was able to recoil at the same speed of the bolt carrier all of the energy of the gas would be for nothing. The bolt carrier wouldn't even move rearward from it's position because the rearward moving gun would move with it at the same speed. This is in theory and the saiga-12 doesn't kick that hard even if it was floating in air completely unsupported. I know we say a loosely held gun causes energy loss but really that is a bad way to state it. There is energy loss of cycling potential but all the energy is still there, it is just cancelled out but the movement of the platform holding the mech.

 

Next, over all weight of the gun, assuming all moving internal parts are the same weight... If your gun weights 30 pounds vs 10 pounds it isn't going to change a thing if the gun is completely stable with zero rearward movement possible. But that isn't how we shoot these things, they do kick. So with that into account a 30 pound gun is going to kick less than a 10 pound gun and there for less of your cycling energy of the carrier will be lost (canceled out). It takes more energy to get a 30 lb object moving than a 10 lb object. But it is not practical to weight down a gun to account for a weak running system and I am sure that some of these guns would still have problems even if you eliminated all recoil movement of the receiver.

 

Weight of the moving parts; bolt carrier, bolt, etc... Changing the weight of the mechanical parts is going to change things. But this is where it gets really tricky with a gillion variables to consider and I won't be going into them all and my human brain can likely only calculate partially without exploding... If you add much weight to the carrier you are going to make more energy required to move it. If you remove weight you are going to reduce the energy required to move it. This can have varying effects. It might take more energy to move a 30 lb object than a 10 lb object but this doesn't necessarily mean reduced weight is good. The carrier is only pushed for a very short stroke. The rest of it's movement is dependent on the transferred energy to it (kinetic energy, inertia). A moving 30 lb object is going to carry a hell of a lot more energy than a 10 lb object moving at the same speed. If you reduce the weight of the carrier will it have enough of this stored energy to finish the cycle against the springs? If you increase the weight of the carrier will it get enough energy to get it moving? It is a delicate balance. I will say this though and please note before hand that I am in no way tied to Ohio Rapid Fire, but when they were working on their galil project this is what the found... The galil charging handle knob... They made some to put on the carriers... They first tried to make these solid without hollowing out the knob... Their guns were failing to eject. They hollowed out the knob and the ejection issue was solved. If you know the size of the knob you know that the amount of material removed to hollow it out is very minimal... In this instance the minimal added weight was enough to make or break the cycling. It is my GUESS that adding weight to the carrier is not ideal and will hurt the cycling some unless you are going to compensate it with increased gas flow or something. It would be easy to test adding weight buy removing the cover and clamping varying weights to the carrier. It would also be easy to test reducing weight to the carrier but might not be as easy to undo this test... I am not recommending anyone try this. It is on our list of test to preform but just haven't got around to it yet...

 

That's exaxctly why I hollow out my charging handle for the most authentic look and light weight.

 

[poolingmyignorance 2,191]

WRONG! If the weapon is truly functioning properly, you could fire it and it would function no matter how you hold/not hold the weapon. It is not blow-back operated, it is gas operated.

 

I've experimented with the way I hold mine since I opened up the ports. It doesn't matter, IF the weapon is functioning properly. If you have to shoulder the weapon hard or put the butt-stock up against a tree, your gun is NOT functioning properly (Mike D, this wasn't aimed at you, we know that you were doing that to test the strength of the front feed-lip of your drum). There is a big difference between functioning and functioning properly...

 

I will say though, that I shoulder the weapon hard to try to be nice to my shoulder, but it doesn't affect my shotgun's performance one bit.

Hey, let's get this straight. I put it against the tree because I'm a big puss. No, I put it against the tree to reduce the forces on the front mag catch. All of those videos of me firing off of a tree was with prototype mags of greatly reduced strength compared to production mags. I did it to keep them from coming apart and breaking, even then it didn't prevent it all the time.

 

The rest of this isn't pointed at you either but just some answers on the question.

 

Weight does matter. First, how a gun is held will affect the function of the gun regardless if it is gas operated. In theory if the gun was able to recoil at the same speed of the bolt carrier all of the energy of the gas would be for nothing. The bolt carrier wouldn't even move rearward from it's position because the rearward moving gun would move with it at the same speed. This is in theory and the saiga-12 doesn't kick that hard even if it was floating in air completely unsupported. I know we say a loosely held gun causes energy loss but really that is a bad way to state it. There is energy loss of cycling potential but all the energy is still there, it is just cancelled out but the movement of the platform holding the mech.

 

Next, over all weight of the gun, assuming all moving internal parts are the same weight... If your gun weights 30 pounds vs 10 pounds it isn't going to change a thing if the gun is completely stable with zero rearward movement possible. But that isn't how we shoot these things, they do kick. So with that into account a 30 pound gun is going to kick less than a 10 pound gun and there for less of your cycling energy of the carrier will be lost (canceled out). It takes more energy to get a 30 lb object moving than a 10 lb object. But it is not practical to weight down a gun to account for a weak running system and I am sure that some of these guns would still have problems even if you eliminated all recoil movement of the receiver.

 

Weight of the moving parts; bolt carrier, bolt, etc... Changing the weight of the mechanical parts is going to change things. But this is where it gets really tricky with a gillion variables to consider and I won't be going into them all and my human brain can likely only calculate partially without exploding... If you add much weight to the carrier you are going to make more energy required to move it. If you remove weight you are going to reduce the energy required to move it. This can have varying effects. It might take more energy to move a 30 lb object than a 10 lb object but this doesn't necessarily mean reduced weight is good. The carrier is only pushed for a very short stroke. The rest of it's movement is dependent on the transferred energy to it (kinetic energy, inertia). A moving 30 lb object is going to carry a hell of a lot more energy than a 10 lb object moving at the same speed. If you reduce the weight of the carrier will it have enough of this stored energy to finish the cycle against the springs? If you increase the weight of the carrier will it get enough energy to get it moving? It is a delicate balance. I will say this though and please note before hand that I am in no way tied to Ohio Rapid Fire, but when they were working on their galil project this is what the found... The galil charging handle knob... They made some to put on the carriers... They first tried to make these solid without hollowing out the knob... Their guns were failing to eject. They hollowed out the knob and the ejection issue was solved. If you know the size of the knob you know that the amount of material removed to hollow it out is very minimal... In this instance the minimal added weight was enough to make or break the cycling. It is my GUESS that adding weight to the carrier is not ideal and will hurt the cycling some unless you are going to compensate it with increased gas flow or something. It would be easy to test adding weight buy removing the cover and clamping varying weights to the carrier. It would also be easy to test reducing weight to the carrier but might not be as easy to undo this test... I am not recommending anyone try this. It is on our list of test to preform but just haven't got around to it yet...

 

That's exaxctly why I hollow out my charging handle for the most authentic look and light weight.

 

 

Interesting. I designed my own, charging handle, and recently posted pics. It's simply a piece of 304 with a 3/8" ball bearing atop it. It hasn't changed my operating at all. BUT what I hadn't stopped to consider was that I had already made my own gas puck thats .024" longer than the orginal. It's worth mention, but i doubt that changed anything, simply because I did the same charging handle mod to my wife's 410 and with NO modification to the gas system and it runs as well as usual. It is how ever an older magnum only model. Before making this modification, I did have it cycling 2 1/2" slugs reliably, if i carfuly loaded the first round by hand. Not sure what any of that means, but I thought it was worth mentioning. (sometimes it's better to be luck than good)

[poolingmyignorance 2,191]

Saigachusa! Where did you get that cool ass muzzle break?!