Ar10 and ar15 buffer tube compatibility

MTS308

Sergeant of the Hide
Full Member
Minuteman
Mar 7, 2018
240
109
Lake butler fl
I have a Seekins sp10 in 6.5 creed and I want to swap from the rifle buffer to a carbine adjustable buffer. I also have a Daniel Defense m4 that I want to build into a mk12 clone. Can I take the buffer tube off the ddm4 and put it on the Seekins? I know the springs and buffers are different but I’m talking about the tubes themselves.
 
Technically speaking, the buffer tubes are the same. A carbine tube is a carbine tube. Can you do it? Yes. Should you do it, that's an arguable point.

For the DD, sure, go ahead and slap a rifle stock setup on it. For the large frame rig? That's a subject of some discussion.

What I really don't like about AR10ish rigs is that they go with that tiny buffer, just so that a standard carbine buffer tube can be used and then they go with a heavy recoil spring to make up for the lack of buffer mass. The problem is that the spring rate actually has very little effect on closed bolt lock time. The best ways to control closed bolt lock time is by either adjusting the amount of gas going into the system or adjusting buffer mass.

The problem with an AR10 with a carbine tube is that the buffer itself, due to its size, doesn't allow for much tuning overhead. If I wanted to go adjustable on an AR10ish rig, I'd go with an A5 buffer tube. It's a little longer than a standard carbine tube and will allow the use of a standard length buffer, allowing for more tune ability through buffer weight, rather than heavy springs, which only affect bolt velocity AFTER the bolt has already unlocked.

Yes, it is possible to have a rifle with, what appears to be, an ideal ejection pattern, while still being overgassed.

Still, can you put a carbine tube on a large frame receiver? Yes, with the appropriate buffer and spring.
 
What Carbine Adjustable Buffer ?

With a AR15 carbine length buffer tube, and a LFAR BCG, you will need a 2.5" buffer... KAK makes a 5.3oz 2.5" 308 buffer ( I think it is sold by various other places, under the brand Midway )

That said 2 of my LFAR's are setup that way, they also use the 2.5" 5.3oz buffer, a Tubbs Flatwire AR10 recoil spring and a SLR Adj. GB.

I have tried all three buffer tube lengths ... AR15 Carbine , A5 / Armalite Carbine and rifle length, IMHO... the adj GB (or a proper gas port size, a rarity I should add ) makes every LFAR run "friendly".

On a side note.... what Carbine stock ?