DefCon (AmmoBros) Lower - MilSpec or Commercial?

[bscruz]

My 10days is about up on my Lower Receiver so I'm starting to order parts (which isn't easy as you all know), but thy are out there in limited supply and still at normal prices at many websites.

I think I recall the guy at the shop tell me that the Def-Con (AmmoBros house brand) lower receiver is Mil-Spec, but I'm not 100% sure.

I'm going to order a stock and buffer tube kit - does anybody know if the DefCon lower fits a Commercial diameter buffer tube or is it the mil-spec diameter?

Thanks

[ke6guj]

well, that AR15 lower you are buying is "commercial", not "mil-spec", since the .mil doesn't not have a spec for a semi-auto AR15 lower, only for full-auto lowers.

that said, the buffer tube threads in the receiver are the same for semi-auto and full-auto receivers. you match the buffer tube to the stock you are using, not to the receiver tht it is being installed

[SixPointEight]

You can put any buffer tube you want on there. As long as your stock matches your tube. No lower you buy will be milspec. Unless its got a hole drilled for the auto-sear pin, and the shelf in back machined out.

[m35a2]

Threads are the same between MIL spec and Commercial. The diameter of the tube is the difference. It is something like 1/16 of an inch difference between the two, the com tube being larger OD.

[bwiese]

• There is no such thing as a 'mil-spec' AR15 lower. Mil-spec is only select-fire M16 with 'happy hole' etc. The term
  'mil-spec' refers to the totality of the system, so saying anything AR15 is 'milspec' is not really accurate - better to
  say "these parts' standards are congruent to those of the M16 spec".
  . .
• Carbine stocks come in 'mil' vs. 'commercial' variants, with differing receiver extension ("buffer tube") diameters.
  ..
• However, the commercial vs. .mil receiver extestion tubes have identical threading to fit into the lower receiver's
  threaded rear lug; there are NO differentiations btwn lower receivers for differing tube sizes.
  . ..
  
• I recommend getting the .mil sized extension/stock combo - more parts variant ability etc.

[Chaos47]

^what they said.
Heres some images to back it up...

[supermario]

Cool diagram.

^what they said.
Heres some images to back it up...

[bscruz]

Thanks guys - would've just bought a complete lower+stock, but I gotta piece it all together this time around - complete lowers - even parts kits are not easy to find right now. I'm gonna get the mil-spec diameter tube and corresponding stock - now to find a website that has the Magpul stock I want Was out today with a deputy and a marine that have a nice collection so I'm building mine with the components on their rifles that I liked.

[Sumo99]

Thanks guys - would've just bought a complete lower+stock, but I gotta piece it all together this time around - complete lowers - even parts kits are not easy to find right now. I'm gonna get the mil-spec diameter tube and corresponding stock - now to find a website that has the Magpul stock I want Was out today with a deputy and a marine that have a nice collection so I'm building mine with the components on their rifles that I liked.

Not sure what Magpul stock you want, but I ordered one of these: http://palmettostatearmory.com/index...build-kit.html

Or they have this one in stock: http://palmettostatearmory.com/index...build-kit.html