All this talk about buffers (confused)

[308sako]

Leads me to asking why?

Heavier buffers will delay the opening of the action and lighter ones will do the opposite. It would appear that most shooters would like to have their rifles run smoothly and 100% without issues.

But I think I am missing something in all this, if a rifle or carbine or SBR functions 100% why would one change out his/her buffer to another weight profile?

Thanks

[polymorpheous]

@308sako

if a rifle or carbine or SBR functions 100% why would one change out his/her buffer to another weight profile?

Thanks

You wouldn’t, unless you are switching to a suppressed system, colder or hotter ammo.

[308sako]

I guess then it is a matter of balance rather than function when chasing the optimal buffer (weight)

Understood regarding the affect suppressors or different ammunition could have on the system.

Thank you for the reply.

[polymorpheous]

It’s all about controlling the cyclic rate.

I run a “H” in both of my 16" mid-lengths.
The bolt locks back consistently on the rare occasion that I shoot under powered Russian ammo.

I run an “H2” in my 10.5" carbine.
If I shoot the Russian stuff through this it short strokes constantly.
If I wanted to run the cheap stuff through the 10.5" I would run a lighter buffer until I found the weight that would allow the bolt to lock back on empty.

[Clint]

Cyclic rate is a combination of three things are at work that need to be in balance.

Moving mass, spring force and gas force.

Gas force is controlled by gas port size, location and ammo loading.

[polymorpheous]

@Clint

Cyclic rate is a combination of three things are at work that need to be in balance.

Moving mass, spring force and gas force.

Gas force is controlled by gas port size, location and ammo loading.

True.
But how many of these variables can be controlled by the end user?

The snake-oil bolt carriers and colored springs can change things up a bit, but how reliable are they?

Ammo and buffers are the cheapest and easiest way to control cyclic rate.
5.56 pressure ammo and a “H” buffer works well in 16" carbine and mid-length guns.

[308sako]

@polymorpheous

True.
But how many of these variables can be controlled by the end user?

Excellent point!

The snake-oil bolt carriers and colored springs can change things up a bit, but how reliable are they?

Also valid, as a smaller part of the cyclic rate control factors… I do not consider these a good approach.

Ammo and buffers are the cheapest and easiest way to control cyclic rate.

Port pressure and dwell time comes from the ammunition and port size, for the most part we cannot control the port size unless we choose to use an adjustable gas block.

5.56 pressure ammo and a “H” buffer works well in 16" carbine and mid-length guns.

Lot’s of If’s associated as the specific chamber and port size have major impact here. So I take this to mean when a true spec chamber and port are present.

Once again thanks, my understanding is getting clearer.

[308sako]

@Clint

Cyclic rate is a combination of three things are at work that need to be in balance.

Moving mass, spring force and gas force.

Gas force is controlled by gas port size, location and ammo loading.

I guess it is that simple. Key factor is achieving the balance which equates to reliable performance and lower wear rates. I find it interesting that with only one exception I can think of (a low mass carrier) the solutions always seem to go up in weight or spring force…

[punkey71]

This touches on something I’ve been thinking about and would like some clarification on.

Buffer weight vs heavier spring. What is the difference between going from a standard spring and car buffer to

a. standard spring and H2 buffer
b. blue sprinco (heavy) and H buffer

How does the spring tension vs buffer weight affect the function/recoil/bolt bounce etc…? What different affect does each have on the weapon?

Just curious and looking to learn.

Thanks,
Harold

@polymorpheous

True.
But how many of these variables can be controlled by the end user?

The snake-oil bolt carriers and colored springs can change things up a bit, but how reliable are they?

Ammo and buffers are the cheapest and easiest way to control cyclic rate.
5.56 pressure ammo and a “H” buffer works well in 16" carbine and mid-length guns.

[markm]

I saw a guy who had a Carbine buffer in his silencer fitted M4.

His gun ran. But the plastic buffer tip was about mushroomed over from slamming into the back of the RE with the force of Thor’s hammer.

So although his gun was running, he should have jumped up at least two buffer weights. His gun seemed to function 100%, but it definitely wasn’t the right buffer.

[Terminator2003]

@punkey71

This touches on something I’ve been thinking about and would like some clarification on.

Buffer weight vs heavier spring. What is the difference between going from a standard spring and car buffer to

a. standard spring and H2 buffer
b. blue sprinco (heavy) and H buffer

How does the spring tension vs buffer weight affect the function/recoil/bolt bounce etc…? What different affect does each have on the weapon?

Just curious and looking to learn.

Thanks,
Harold

These are some great questions which I am curious about also. I started another thread asking about the correct buffer for my midlength, but these details you mention never came into the discussion.

[308sako]

@punkey71

This touches on something I’ve been thinking about and would like some clarification on.

This is still on target, thanks

Buffer weight vs heavier spring. What is the difference between going from a standard spring and car buffer to

Or should both be changed to maintain some sort of true balanced system?

a. standard spring and H2 buffer
b. blue sprinco (heavy) and H buffer

How does the spring tension vs buffer weight affect the function/recoil/bolt bounce etc…? What different affect does each have on the weapon?

I’m pretty sure that the heavier buffer weight affects the inertia which must be over come to allow the carrier to begin to move in the cycle. The heavier spring as I see it is to slow the motion of the newly energized carrier and obviously to complete the return to battery portion of the cycle.

As to bolt bounce… wow another WTHades but this is also important as I will ASSUME that bolt bounce would fall into the out of balanced system category.

Thanks for the thoughts.

Just curious and looking to learn.

Thanks,
Harold

Well done

[308sako]

@markm

I saw a guy who had a Carbine buffer in his silencer fitted M4.

His gun ran. But the plastic buffer tip was about mushroomed over from slamming into the back of the RE with the force of Thor’s hammer.

So although his gun was running, he should have jumped up at least two buffer weights. His gun seemed to function 100%, but it definitely wasn’t the right buffer.

Thanks for explaining an example of the need for, and the possible damage caused by an out of balance system.

Could you describe what the symptoms would be of a system being run with spring and buffer choices that were too heavy?

Thanks again

[markm]

@308sako

Could you describe what the symptoms would be of a system being run with spring and buffer choices that were too heavy?

Sluggish cycle and weak ejection. Also… failure to lock back and/or failure to strip a new round/bolt over.

There’s just a Chunk-Chunk feel to a gun that’s over buffered.

[MarkG]

@markm

I saw a guy who had a Carbine buffer in his silencer fitted M4.

His gun ran. But the plastic buffer tip was about mushroomed over from slamming into the back of the RE with the force of Thor’s hammer.

So although his gun was running, he should have jumped up at least two buffer weights. His gun seemed to function 100%, but it definitely wasn’t the right buffer.

To illustrate markm’s point…

Here is an example of why you shouldn’t put a suppressed HK416 upper on a rare M16A2 lower (100% Colt parts - H buffer). The bolt group was coming to its usual and sudden stop at the back of the receiver extension with enough force (that of Thor’s hammer) to compress the pad on the buffer to the point that the gas key was able to come into contact with the lower receiver. You couldn’t fit a heavy enough buffer into the receiver extension to prevent the damage. While exaggerated, this is a perfect example of why gas piston systems are not the cats meow…

On the plus side, he now has a staked receiver extension.

[orionz06]

@308sako

But I think I am missing something in all this, if a rifle or carbine or SBR functions 100% why would one change out his/her buffer to another weight profile?

Often times people just tinker for the sake of tinkering without knowing exactly what they are doing. It is the cool thing to do to add a heavier buffer. It’s tactical, it’s the latest craze, and in a month or so there will be something new to come along that allows shooters to reduce the reliability of their guns.

[markm]

@MK18Pilot

On the plus side, he now has a staked receiver extension.

:lol: People are going to want that service.

[Scoby]

I recently did alittle experimenting with buffers just to see what all the fuss was about and ATF recently allowed me to pickup my new suppressor. I wanted to see what worked and what didn’t, suppressed and unsuppressed. I was going to post this as a separate thread but…I’m certain nobody wants to see yet another buffer thread.

As you’ll see…I went around the world only to come back to where I was standing to start with. Live and learn I suppose.

For what it’s worth.

Firearm:
LMT Complete Lower w/BAD Lever & CTR Stock
BCM Upper, Daniel Defense 14.5” MidLength Barrel & AAC 51T Brakeout Comp
Suppressor – AAC M4-2000
Mags – 30rd PMags (#7)
Ammo – PPU .223 75gr BTHP Match – 5 rounds fired for each configuration

Note: I normally run a BCM FA BCG, Springco CS Blue Spring and an H Buffer for this firearm and have done so through over 2k of ammo with no issues at all prior to getting the suppressor.

Configuration #1 - BCM FA BCG / Springco Blue Spring

 [u]Carbine Buffer[/u]:  

Unsuppressed – recoil was mild, bolt locked back on empty mag, no malfunctions

Suppressed - recoil was mild, bolt locked back on empty mag, no malfunctions

 [u]H Buffer[/u]:  

Unsuppressed – recoil was mild, bolt locked back on empty mag, no malfunctions

Suppressed - recoil was mild, bolt locked back on empty mag, no malfunctions

H2 Buffer:
Unsuppressed – recoil was mild/maybe lighter, bolt locked back on empty mag, no malfunctions.

Suppressed - recoil was mild, bolt locked back on empty mag each time. Three different times, out of five rounds, the bolt stripped a round but the bolt FAILED close completely.

Configuration #2 – LMT Enhanced BCG (std bolt) / Std Carbine Spring

 [u]Carbine Buffer[/u]:  

Unsuppressed - recoil was mild, bolt locked back on empty mag, no malfunctions

Suppressed – recoil was mild, bolt FAILED to lock back on an empty mag. This configuration was tested three times with the same results.

Configuration #3 – LMT Enhanced BCG (std bolt) / Springco Blue Spring

 [u]Carbine Buffer[/u]:  

Unsuppressed - recoil was mild, bolt locked back on empty mag, no malfunctions

Suppressed – recoil was mild, bolt FAILED to lock back on an empty mag. This configuration was tested twice with the same results.

As stated before, I’m back to the BCM BCG, H buffer and Springco blue spring shooting suppressed and unsuppressed without any problems. Right where I started from.

I did take it alittle further and bought some PMC Bronze just to see if it would run weaker ammo. It did without any problems.

Also, does anyone notice anything odd about configuration #2 that theoretically I would not have expected? Any thoughts on this?

[col.1981]

@MK18Pilot

To illustrate markm’s point…

Here is an example of why you shouldn’t put a suppressed HK416 upper on a rare M16A2 lower (100% Colt parts - H buffer). The bolt group was coming to its usual and sudden stop at the back of the receiver extension with enough force (that of Thor’s hammer) to compress the pad on the buffer to the point that the gas key was able to come into contact with the lower receiver. You couldn’t fit a heavy enough buffer into the receiver extension to prevent the damage. While exaggerated, this is a perfect example of why gas piston systems are not the cats meow…

On the plus side, he now has a staked receiver extension.

Wow! That’ll make you sick.

[308sako]

@MK18Pilot

To illustrate markm’s point…

Here is an example of why you shouldn’t put a suppressed HK416 upper on a rare M16A2 lower (100% Colt parts - H buffer). The bolt group was coming to its usual and sudden stop at the back of the receiver extension with enough force (that of Thor’s hammer) to compress the pad on the buffer to the point that the gas key was able to come into contact with the lower receiver. You couldn’t fit a heavy enough buffer into the receiver extension to prevent the damage. While exaggerated, this is a perfect example of why gas piston systems are not the cats meow…

On the plus side, he now has a staked receiver extension.

That is just too funny, except to the owner… Duh!