Buffer Type?

[Shihan]

Im sure this has been asked to death but what ype of buffer should be used with a 16" carbine?
Also what type comes standard from the factory with a
M&P15T
LMT lower ?


Thanks

[gotm4]

With your set up I'd use an H buffer.

S&Ws come with a CAR buffer from the factory.

The H will help slow it down and stop any extraction issues. I'd also be sure it had a black extractor buffer and I'd use a Crane 0-ring or MGI D-fender extractor enhancer over the extractor spring.

[LukeMacGillie]

Use the buffer that comes with the gun, up until such point that the gun does not run. Then consider respringing/buffering.

[twl]

Often the one that comes with the gun when new is the best one to start out with.

As time goes on, you may experience some gas port erosion, which would cause the gas port to enlarge, thereby altering the balance between the gas metering and the moving masses(which includes the buffer). This changes the cycling behavior.

You can help to restore the balance after that occurs by using a heavier buffer.
The buffer should allow good function of the weapon with a variety of ammunition, and in a variety of operating temperatures.

Too heavy buffers can cause short-stroking, and too light buffers can cause overcycling. Strive for a good balance.

[Shihan]

Im making a parts order for a customer this week so I figured I would pick up some stuff for myself while I was at it and had no idea what type to order for myself. Life was easy when I would just have the armorer do anything that was needed.

So to verify from the factory

S&W M&PT uses a standard Car buffer?

LMT uses a H-Buffer?

Thanks

[tiger seven]

My LMT lower came with a standard carbine buffer in it.

Derek

[Shihan]

I called LMT and they said the H-buffer would work better and then I called Stag and they said the standard buffer would work better unless I was using the weapon on full auto.
Is there any down side to using a H-buffer?

[gotm4]

Originally Posted by Shihan

I called LMT and they said the H-buffer would work better and then I called Stag and they said the standard buffer would work better unless I was using the weapon on full auto.
Is there any down side to using a H-buffer?

If using very weak ammo it might not lock the bolt back.

[msr]

How about a buffer recommendation for an 11.5"?

[gotm4]

Originally Posted by msr

How about a buffer recommendation for an 11.5"?

H to H2.

[watchluvr4ever]

My brand new LMT CQB length MRP with 16" barrel came with a CAR buffer. Should I leave it be or put in a heavier buffer? If yes what buffer? BTW, I haven't shot it yet because I'm waiting on my sights. Thanks!

[welchtactical]

I've been using the H buffers for a while now with a Wolff extra power spring. Seem to work pretty well. A must with Piston ARs IMHO.

[gotm4]

Originally Posted by watchluvr4ever

My brand new LMT CQB length MRP with 16" barrel came with a CAR buffer. Should I leave it be or put in a heavier buffer? If yes what buffer? BTW, I haven't shot it yet because I'm waiting on my sights. Thanks!

LMTs run slightly small gas ports and run fine on CAR weight buffers. I'd just run a CAR buffer.

[Buckaroo]

At the risk of outing myself as a real noob.....

What does a piston upper need a buffer for?

[gotm4]

Originally Posted by Buckaroo

At the risk of outing myself as a real noob.....

What does a piston upper need a buffer for?

The buffer is the thing that pushes the carrier forward again. Regardless if an AR is direct impingment or piston it still needs a buffer.

[Buckaroo]

So there must be an "H" buffer for a piston system.

That makes sense. It just confused me when the discussion went from DI to Piston uppers and it appeared that the buffers were the same.

I have no exposure to Piston uppers so thanks for helping me learn something!

[gotm4]

Originally Posted by Buckaroo

So there must be an "H" buffer for a piston system.

That makes sense. It just confused me when the discussion went from DI to Piston uppers and it appeared that the buffers were the same.

I have no exposure to Piston uppers so thanks for helping me learn something!

A H buffer is a H buffer regardless of the type of upper on the lower.

It's like saying there two different 17" Wheels for Mustangs (one for supercharged models and another for naturally aspirated models). The wheels don't know.

[C4IGrant]

The gas port size in the gun plays a big part in the equation. LMT uses very small gas ports in the 10.5's as they are intended to run on FA. So generally I would run no more than an H buffer in these weapons.

For most any other weapon with a carbine gas system. I would run either an H or H2 and a quality spring (CS is preferred).

All Stag, S&W, BM, RRA, DPMS, Oly and LMT's come with carbine buffers.

Colt is one of the few companies that ships their weapons with H and sometimes an H2 buffer.


C4

[Buckaroo]

Originally Posted by gotm4

A H buffer is a H buffer regardless of the type of upper on the lower.

It's like saying there two different 17" Wheels for Mustangs (one for supercharged models and another for naturally aspirated models). The wheels don't know.

OK, so I am off to research piston uppers. Thanks for helping!

[UPSguy]

I understand that if you have too heavy of a buffer a sympton is failure to lock open. How do you know if you need a heavier buffer?