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AR10 buffer tube selections

kenny1773

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Jun 7, 2019
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I am trying to figure out what the differences are between using the different length buffer tubes on an AR10 - DPMS style (Aero M5 to be more precise)

I currently have an Aero 7" carbine buffer tube, the one that uses the 2.5" buffer
I am looking to build a second lower and thought I might use the longer buffer tube for this one

I see there is a 7.75" buffer tube out there, Spike Tactical to be more precise
and that looks like it would let me use 3.25" buffers

These two length tubes look like they use the same springs

Am I missing anything here? or as long as I use the correct length buffer with the correct length tube, can I use either length on an AR10?
 
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DRAM40A1

Thanks! That is they type of feedback I was looking for.

Everything cycles ok? no issues to speak of?

I was having cycling issues with the stock spring and stock buffer on the 7"
I put an armaspec 5.7oz captrued spring in that one and that helped a ton

but I wanted to try the 7 3/4 tube and 3.25 buffer if that is working for others
 
I have a KAC/LMT SOPMOD stock for sale on here FWIW... The whole thing, 9pos. tube, buffter, sling mount, etc.

I did use it a few times on an SR25 before I installed a fixed stock. It never had a problem. And honestly I can't say as the fixed stock is really any better and the SOPMOD has a really nice cheekweld to begin with so I guess I can see why KAC started using these. I guess with hindsight I probably would have just kept the SOPMOD on it.

As for different buffers, can't say, only have the one .308 but it's made by the company that invented this shit and they've got a good track record for making stuff that works.

Now with standard AR's, the A7 buffer I have on one is much softer than the standard one it replaced. This is due more to weight differences than length IMO, and it even comes with a plug so you can use the smaller buffer in the longer tube.
 
DRAM40A1

Thanks! That is they type of feedback I was looking for.

Everything cycles ok? no issues to speak of?

I was having cycling issues with the stock spring and stock buffer on the 7"
I put an armaspec 5.7oz captrued spring in that one and that helped a ton

but I wanted to try the 7 3/4 tube and 3.25 buffer if that is working for others

I’m running the same set up on an LMT lower with a KAC SR 25 upper, a 6 MM Creedmoor and a 6.5 Creedmoor. They all run great with this set up. I’m using the 5.4 oz H3 buffer but I think KAC uses an H2 buffer weight.

Everything I’ve seen with the short/light 308 carbine buffer has issues with cycling, especially in high pressure cartridges.
 
The Armalite kit is a bargain @$65 and they do make a 7 position tube also, but you would have to call CS for it. I just swapped
the PRS out on mine for the Sopmod. The Armalite spring is the same part for rifle and carbine.
 
I am trying to figure out what the differences are between using the different length buffer tubes on an AR10 - DPMS style (Aero M5 to be more precise)

I currently have an Aero 7" carbine buffer tube, the one that uses the 2.5" buffer
I am looking to build a second lower and thought I might use the longer buffer tube for this one

I see there is a 7.75" buffer tube out there, Spike Tactical to be more precise
and that looks like it would let me use 3.25" buffers

These two length tubes look like they use the same springs

Am I missing anything here? or as long as I use the correct length buffer with the correct length tube, can I use either length on an AR10?


Your last comment is fully correct.

The advantage to the longer buffer tube and the 3.25" buffer length is readily available 3.25" buffers and heavier weight buffer.

I use a Tubbs .308 Flatwire recoil spring in both "patterns" and even the rifle length recoil setup.
 
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