View Full Version : ?? question about DPMS buffer tube ??

January 15, 2013, 12:43 AM
I'm trying to put together a AR15. Please correct me if I'm wrong. Buffer tube comes in 3 lenghts. Pistol, Carbine, and Rifle. I'm working w/ a 20" RRA 0550 varmint upper. I've been told that an A2 Stock is nice for this gun, and that a carbine buffer could be used on barrels up to 20". Was also advised to stick to milspec tube. I'm able to get a "Panther Arms DPMS BS-10 kit. I'm asking for help on what this kit is? Is it milspec? Is buffer tube in this kit rifle length or carbine? Also what all determines what length buffer tube to use, or whats the ideal length tube for the upper I desribed? Is the part number of the kit I described a descent kit? Are the buufer tubes somewhat smooth on inside? Are threads cut for nice fit to receiver? I'd appreciate anyones thoughts on this. This kit is the only thing I'm lacking to put together a complete gun I believe. thanks

January 15, 2013, 08:42 AM
To my knowledge buffer tubes for "pistols" are usually the same length as carbine tubes but don't have the lug and detents for the rest of the stock which is illegal on a pistol. There are some proprietary pistol tubes that require a special buffer.
Carbine tubes use carbine buffers and A2 "rifle" tubes use rifle buffers. Using a carbine buffer in a rifle length tube will break stuff. Using a rifle length buffer in a carbine tube will not allow it to work.
ALL buffer tubes for the AR15 have the same threads on the receiver end. There are 2 lengths of rifle stock-A1 and A2 with the A1 being slightly shorter. The tubes are the same for both. The difference between mil-spec and commercial carbine tubes is in the outside diameter with the commercial being slightly bigger. Commercial stocks usually fit on mil-spec tubes but are quite loose fitting. Vice versa is a no fit.
The rifle buffer tubes tighten against the back of the lower.The carbine tubes have a lock ring that tightens against the lower.
The tubes are smooth inside since the buffer and spring have to reciprocate.
Carbine stocks on 20" rifles make for a muzzle heavy combination which I don't care for. My Son likes his so it's more a preference thing. There is no real requirement for stock length although I choose to use A2 stocks on rifles for the balance and when shooting from the bench, the A2 is more support friendly.

January 15, 2013, 09:28 AM
Can you provide a link to the specific kit you are talking about? Unless I am mistaken the BS10 is for a .308 rifle. Everything in this kit should work fine with the possible exception of the buffer and spring. Not certain but I would assume a .308 may have a heavier buffer than a 5.56 rifle.

January 15, 2013, 09:39 AM
Thank you Mobuck. Nice explanation. It sounds like the carbine uses a castle nut, but I'm unclear if rifle buffer does? Does rifle tube have a shoulder or something that bottoms out against receiver? Anyway, this kit comes w/ an A2 stock. It comes in a plastic package that has the buffer spring bent over at a 90 degree anfle at top. Can anyone vision this kit in their mind? Its part number is BS-10. I'm trying to determine if this is a buffer tube for rifle or carbine. Also is it the right setup for the upper I described. I don't mean to sound lazy, like I can't get to the bottom of this myself, but every time I hesitate on buying an AR part, it's sold out of stock when I come back. At this point I wish I would have just bought the gun complete. So any responses on this or advice would be helpful.

January 15, 2013, 10:02 AM
Yes, the rifle buffer tube has a shoulder that holds the takedown pin detent spring in place. If this one is a kit that comes with an A2 stock it is definitely a rifle bufffer and spring. My concern was if it was for a .308 or .556 or if there is any difference. I tried to just google the DPMS BS10 and came up with a kit for a .308.
Edit: I found it, won't say where, but this is what you want for a fixed stock. It is actually the same kit I bought for mine now that I see it in print. the buffer tube (AKA receiver extension) screws directly into the receiver. The stock is held in place by the rear top butpad screw. Most of these come with an A1 buffer tube now so they have a 1" spacer included. The A2 stock is 1" longer than the A1 stock.

January 15, 2013, 08:30 PM
Thanks Slappy. I'm confused now also. Is this for a 308 or ar 15?

January 15, 2013, 09:34 PM
Brownells has it listed as a standard AR15 part, not AR10, SR25, or LR308.


A carbine length buffer will work in a rifle length tube, I ran a lightweight setup like that for years without issue.

January 16, 2013, 03:57 AM
Thanks Sailskidrive. Thanks to the other guys that responded to this also. Alot of ads advertisr this as 308. But your right Brownells lists it for ARs also. I wish I would have caught that earlier. Its probally just a diff in springs like the other posts said. Anyway, its to late now, the auction ended and I didn't bid on it. O well, thats what I get for not doing my homework.

January 16, 2013, 06:30 AM
"A carbine length buffer will work in a rifle length tube"
I must be confused also. Since the buffer limits the rearward travel of the BCG, how does this work correctly with a short carbine buffer in a long rifle tube? If this is right, there would be no need for different buffers.

January 16, 2013, 10:11 AM
"A carbine length buffer will work in a rifle length tube"
I must be confused also. Since the buffer limits the rearward travel of the BCG, how does this work correctly with a short carbine buffer in a long rifle tube? If this is right, there would be no need for different buffers.

You can use a carbine buffer in a rifle RE IF you use a spacer with it. The spacer makes the carbine buffer longer. Just another tuning aid, allows you to change buffer weights even with the rifle RE's.

The DPMS part # BS10 is a standard AR15 RE and butt assembly. DPMS uses this on their .308 AR's with a different buffer and spring.

January 16, 2013, 05:12 PM
yes... my apologies... I forgot to mention the spacer. :D