Relationship between buffer weight and spring weight??

[m1a convert]

If a gun is over gassed I can fix it by putting a heavier and heavier buffer in it. I can also fix it by increasing the spring power. I know it is best to do it by using a combo of both. I am wondering what the dynamics are of changing each component and if you increase spring rate first then increase buffer rate etc.

Thanks

[gaijin]

Sort of- but you don't "fix" overgassed by spring/buffer. You fix it by reducing gas port diameter- or similar.

The spring/buffer is a bandaid that helps, but doesn't correct the issue.

[1168]

Black River Tactical EZ Tune gas tube. Colt spring. Maybe Sprinco Blue. H1 or H2 buffer. Ammo.

[m1a convert]

Sort of- but you don't "fix" overgassed by spring/buffer. You fix it by reducing gas port diameter- or similar.

The spring/buffer is a bandaid that helps, but doesn't correct the issue.

I knew when I typed that it would be pointed out that the solution to over gassed is an adjustable gas block. I have 11 guns I am working with on this. Two have adjustable gas blocks and I went that route on those two. I don't want to buy 9 more adjustable gas blocks for the other rifles. I just want to understand how changing the buffer affects the system vs changing the spring. Of the 9 rifles, 4 have VLTOR A5 systems and the rest are standard collapsible buffer tubes.

I appreciate responses where guys are telling me what combo they use but that isn't the info I am after. I am looking for the mechanics of what each of these changes (buffer vs spring) has on the system.

Ex : Heavier spring slows down recoil stroke and buffer delays unlocking so you need to increase spring rate first until XXX happens and then at that point work on determining the correct buffer until XXX happens.

That was just an example above but I am trying to figure out the effect of changing each of these components and the proper order/procedure to use to figure out the optimum combo.

[alx01]

I'm just curious - you have 11 rifles and all of them are over-gassed? Or do you think they are over-gassed? Are you basing it on some concrete evidence or just going by the feeling?

I think too many people on this board and others are way too concerned about gassing issue to the point where their rifles barely run. Even somewhat generously gassed Palmetto barrels are actually fine in most cases.

Try using a good muzzle break to see if that helps with the recoil feeling.

[m1a convert]

I'm just curious - you have 11 rifles and all of them are over-gassed? Or do you think they are over-gassed? Are you basing it on some concrete evidence or just going by the feeling?

I think too many people on this board and others are way too concerned about gassing issue to the point where their rifles barely run. Even somewhat generously gassed Palmetto barrels are actually fine in most cases.

Try using a good muzzle break to see if that helps with the recoil feeling.

Maybe I should have avoided using the word over gassed. I have buffers ranging from Spikes T2 up to H3 with standard buffer springs on the carbine systems and A5A3 and A5A4 buffers on the VLTORS.

I am not looking as much for problem solving as I am understanding the mechanics of how changing each part affects function and the proper order to go through to find the optimum spring/buffer combo for each rifle or any rifle.

[Diamondback]

OP, I gotta applaud you though I have no useful info to contribute--so many today just look for the "gimme a fish" of a direct answer to their immediate problem without seeking the "teach me HOW to fish" of learning the process. :)

[markm]

Before I started addressing the actual over gassing of many of my guns, I was doing the buffer thing. My approach was to NEVER deviate from a Colt factory spring after trying a CS spring that caused complete misery for one of my carbines.

I'm not a physicist, but I think a heavier spring is going to snap back more rapidly which does nothing to fix the excessive bolt speed that's the root of the problem. A heavier buffer with the standard spring is going to both slow the rearward travel as well as the forward travel.

[GH41]

Before I started addressing the actual over gassing of many of my guns, I was doing the buffer thing. My approach was to NEVER deviate from a Colt factory spring after trying a CS spring that caused complete misery for one of my carbines.

I'm not a physicist, but I think a heavier spring is going to snap back more rapidly which does nothing to fix the excessive bolt speed that's the root of the problem. A heavier buffer with the standard spring is going to both slow the rearward travel as well as the forward travel.

I guess nobody but us remembers old Albert and the equal/opposite reaction thing. If a weight (buffer) is heavier and harder to get going against the spring it will return to battery more violently. Where do they want the recoil impulse? People make fun of me for running a "0" A5 buffer in a BCM/ELW upper. It works 100% of the time with any ammo. I don't care where the brass lands!! The rifle working 100% of the time is more important to me than recoil impulse or a little wear and tear.

[lysander]

The problem is the increasing the spring weight does far less at reducing bolt velocity than adding mass to the moving parts.

The force on the piston is about 800 to 1000 pounds, so if you double the spring rate the effective force is still 790 to 990 pounds, that is not going to change the velocity much. But, increasing the mass by an ounce can reduce the bolt carrier velocity by about 1.5 fps.

Increasing the spring weigh really just increases the forward velocity of the carrier when it returns to battery.

[Clint]

The gas system imparts more or less constant impulse / momentum to the moving mass.

Heavier buffers reduce recoil and counter recoil velocities, along with recoil energy. E = 1/2 m v^2

Heavier springs can absorb and release more recoil energy.

This is all complicated by the fact that excess recoil energy is stored and mostly returned by the buffer tip, resulting in more counter recoil energy and bolt bounce upon return to battery.

************

As mentioned earlier, adding excess buffer and spring do not correct over gassing. They only attempt to mask it.

The most direct way to fix actual over gassing is to reduce the gas port.

[lysander]

The gas system imparts more or less constant impulse / momentum to the moving mass.

Heavier buffers reduce recoil and counter recoil velocities, along with recoil energy. E = 1/2 m v^2

Heavier springs can absorb and release more recoil energy.

This is all complicated by the fact that excess recoil energy is stored and mostly returned by the buffer tip, resulting in more counter recoil energy and bolt bounce upon return to battery.

************

As mentioned earlier, adding excess buffer and spring do not correct over gassing. They only attempt to mask it.

The most direct way to fix actual over gassing is to reduce the gas port.
To further expound:

Force = mass x acceleration

if the force from the gas system is more or less a constant, 800 to 1000, pounds, and a stiffer spring does not reduce this, the only way to reduce the acceleration is more mass.

Higher acceleration = higher velocity = higher energy.

All that energy is stored in a spring and therefore returned when the bolt starts to move forward.

There are only two ways to reduce the energy in the system: 1) increase the mass (heavier parts), or 2) reduce the force (smaller gas port).

[RVTMaverick]

BEST Fix... as some others have already said here.... Smaller Gas Port
Here, I'll hook You up with the "Shortcut" >>http://www.blackrivertactical.com/concrete5/contact/

[Dr. Bullseye]

I was researching buffers once and found this video.

Buffer Theory 35 minutes
https://www.full30.com/watch/MDEyODMw/the-buffer---theory-and-when-to-use-what-buffer

[vicious_cb]

I was researching buffers once and found this video.

Buffer Theory 35 minutes
https://www.full30.com/watch/MDEyODMw/the-buffer---theory-and-when-to-use-what-buffer

Remember when I said this dumbass video is going to mislead people into picking buffer weights based on barrel profile. Voila here you are folks.

https://www.m4carbine.net/showthread.php?212250-Small-Arms-Solutions-video-quot-The-Buffer-Theory-and-when-to-Use-What-Buffer-quot/page6

[AndyLate]

I can select parts and assemble satisfactory ARs and still don't understand what the "perfect" relationship between buffer weight and spring strength should be.

If I was trying to tune 9 different ARs, I would be reaching out to the barrel or URG manufacturer for recommendations.

Andy

[Clint]

Just wanted to clarify this point.



The gas system imparts more or less constant impulse / momentum to the moving mass.


The magnitude of this impulse is directly related to the gas port area, gas system configuration and of course, the cartridge pressure curve.

[Dr. Bullseye]

Remember when I said this dumbass video is going to mislead people into picking buffer weights based on barrel profile. Voila here you are folks.

https://www.m4carbine.net/showthread.php?212250-Small-Arms-Solutions-video-quot-The-Buffer-Theory-and-when-to-Use-What-Buffer-quot/page6

Don't you think you are miss-characterizing this video quite a bit? He discusses many variables, which is my point, and mentions barrels at the 18 minute mark or so and then in the context of full auto and says in semi auto you should stick to the buffer which came with your rifle in most cases.