Buffer Specs

[44Dave]

I'm trying to decide if this carbine buffer I have is suitable (or be made suitable) for the 308 I'm putting together.  Can anyone give me the ideal weight and length of a carbine buffer? 

 

If it matters this will probably end up being an 18" barrel with rifle gas. 

[shibiwan]

308 buffers are typically around 3/4" shorter than their standard 5.56 counterparts (this applies only to DPMS pattern rifles with AR-15 buffer tubes).

 

For Armalite, you can use standard rifle or carbine buffer with their respective Armalite-length buffer tubes.

 

Most here would recommend as heavy a buffer as you can get, with the upper limit around 10-12oz, the most important factor here is the rifle being able to cycle rounds reliably and not short stroking.

[edgecrusher]

Reference Heavybuffers.com, he has a table to give you an idea on the sizes and weights. Typically you should be planning on this being a .308ar specific part.

Btw, I use only his ^ buffers. In my 5.56 and .308 rifles, just good stuff!

[shibiwan]

Made :D :D :D

[FaRKle!]

Can anyone give me the ideal weight and length of a carbine buffer? 

 

If it matters this will probably end up being an 18" barrel with rifle gas. 

 

Ideal weight will depend on your gas port size as well. Chances are your gun is over gassed, so a heavier buffer (at least H3 - 5.6oz) would be the area you'd start. I'd also go with an Armalite or VLTOR A5 receiver extension so you can use the longer Armalite spring and standard AR-15 carbine profile/sized buffers.

[44Dave]

Well, it looks like the weight of the buffer is good, not sure about the length though. 

Truth be told, I'm looking at reusing a 9mm-Q buffer from Heavy Buffer. 

[98Z5V]

Well, it looks like the weight of the buffer is good, not sure about the length though. 

Truth be told, I'm looking at reusing a 9mm-Q buffer from Heavy Buffer. 

Won't work, no matter how you slice it, brother.  The 9mm Q, and 45 ACP-specific buffers are a little bit longer than the standard AR15 carbine buffer.  That's to prevent the shorter 9mm and 45 bolt carrier overtravel.

 

For a 308AR, you need something a little shorter than the standard AR15 stuff - not a little longer.  <<< Armalite-specific parts not included in that reference.

[44Dave]

Yeah, that's what I was afraid of.  It was really hard to uncover the differences between all the buffers though.  The best resource was that chart @ Heavy Buffer, but even he had some data redacted so you couldn't figure it all out at one place.