AR10 upgrade buffer&spring - opinions?

[Lincoln7]

The 308AR can use:
A5 (VLTOR variety) length receiver extension using an AR15 carbine buffer
or
Carbine (AR15 variety) receiver extension using the shorter 308 buffer

Don't know if this helps you any

[MistWolf]

Hmmm what would you suggest ?

Take your 308 BCG, buffer & spring and compare them to your 5.56 carrier, buffer & spring. Using a 24 inch scale, measure the internal length of both buffer tubes.

From you description of your 308 having a shorter buffer, my guess is your 308 uses a carbine RE.

If you use a rifle RE on your 308, a rifle buffer will be too long, and both the A5 and carbine buffer will be too short. To use a rifle RE, you'll need to use either an A5 buffer or carbine buffer and a spacer.

[grizzman]

If we don't start specifying buffers as either 308 or AR-15 in all instances, we're gonna make 2NadZ even more confused.

[2NaDZ]

If we don't start specifying buffers as either 308 or AR-15 in all instances, we're gonna make 2NadZ even more confused.

Lol 😂

[2NaDZ]

Take your 308 BCG, buffer & spring and compare them to your 5.56 carrier, buffer & spring. Using a 24 inch scale, measure the internal length of both buffer tubes.

From you description of your 308 having a shorter buffer, my guess is your 308 uses a carbine RE.

If you use a rifle RE on your 308, a rifle buffer will be too long, and both the A5 and carbine buffer will be too short. To use a rifle RE, you'll need to use either an A5 buffer or carbine buffer and a spacer.

I just did rough estimates real quick starting with .223/5.56
bolt carrier length - 7.5”
Spring - 10 3/4” 36 coils
Buffer - 3 1/4”

The .308 -
Bolt carrier length - 8 3/4”
Spring - 10 3/4” 26 coils
Buffer- 2 1/2”

Both adjustable carbine buffer tubes measured the same @ 7 1/4” with inner diameters @ 1” roughly (original buffer tubes bought w/ guns) The rifle buffer tube I purchased is 10 1/4” and has the same inner dimensions.
The charging handles on .223/5.56 is 7”
.308 8” - bit longer

[grizzman]

Your carbine 308 buffer does meet the DPMS standard. It, paired with the carbine AR-15 receiver extension, means that your bolt carrier is also DPMS length.

Your plan to use a 5.2" long 308 rifle buffer with an AR-15 rifle receiver extension will "work".

[2NaDZ]

Your carbine 308 buffer does meet the DPMS standard. It, paired with the carbine AR-15 receiver extension, means that your bolt carrier is also DPMS length.

Your plan to use a 5.2" long 308 rifle buffer with an AR-15 rifle receiver extension will "work".

so understanding that I have a carbine RE … but using an ar15 RE which is different then an actual Rifle RE from a 308? total guess
so there is dpms and armalite? or what are you referring to?

[grizzman]

so understanding that I have a carbine RE … but using an ar15 RE which is different then an actual Rifle RE from a 308? total guess
so there is dpms and armalite? or what are you referring to?

I don't really comprehend your first sentence. As far as I know, there is no such thing as a 308 rifle-length receiver extension that's different than an AR-15 rifle length receiver extension.

My understanding of your situation is that the rifle came with an AR-15 carbine receiver extension and a 2.5" long 308 buffer. These meet the standard that's typically called DPMS. The receiver extension has been replaced with an AR-15 rifle receiver extension and Magpul AR-15 fixed MOE stock. Back during the AWB, I ran my 308 AR with an A2 fixed stock and a 308 rifle buffer. This buffer has been sitting in a drawer for years.

In addition to DPMS, there is Armalite as the other old standard. Other brands exist that are hybrids of the two, or partially standardized and partially unique, or mostly unique to that rifle.

[2NaDZ]

I don't really comprehend your first sentence. As far as I know, there is no such thing as a 308 rifle-length receiver extension that's different than an AR-15 rifle length receiver extension.

My understanding of your situation is that the rifle came with an AR-15 carbine receiver extension and a 2.5" long 308 buffer. These meet the standard that's typically called DPMS. The receiver extension has been replaced with an AR-15 rifle receiver extension and Magpul AR-15 fixed MOE stock. Back during the AWB, I ran my 308 AR with an A2 fixed stock and a 308 rifle buffer. This buffer has been sitting in a drawer for years.

In addition to DPMS, there is Armalite as the other old standard. Other brands exist that are hybrids of the two, or partially standardized and partially unique, or mostly unique to that rifle.

What does during AWB mean? And why has ur rifle buffer been sitting in a drawer, did you not like the fixed stock and assume went back to adjustable

[grizzman]

Sorry, AWB is short for the assault weapons ban from 1994 to 2004.....when new adjustable stocks were illegal to sell. I ran an A2, because it was pretty much either that or a lousy M4/CAR stock that was pinned in the fully extended position.

I actually like fixed stocks. I use a Magpul MOE stock paired with an upper with 20" A1 profile barrel and rifle length MOE handguards, and irons.
That old A2 stock lives on a PSA with MOE middy handguards, and irons.

Once the assault weapons ban ended, the 308 got a carbine RE and a LMT SOPMOD stock. The RE's been installed since, but the stock has changed numerous times.