Which PSA Lowers Are Mil-spec?

[HGM22]

http://palmettostatearmory.com/index.php/ar-15-05/lowers.html

I see all these different lowers but I'm not sure which are mil-spec. and which aren't (i.e. I assume the "mil-spec diameter receiver extension" is meant to sound mil-spec but is not explicitly so). Could someone help me?

Please let's not turn this into a love/hate PSA thread or get super technical as to what exactly is mil-spec. When I say mil-spec. I mean "follows or exceeds TDP as closely as possible" (think BCM, DD, etc.).

 

[HOOfan_1]

They don't seem to state the alloy composition of the receiver extension. Milspec is 7075. A lot of companies use 6061

 

[NWcityguy2]

I don't think PSA has ever offered a completed carbine lower with a 7075 aluminum buffer tube. If it is 7075 then they will say, if it is 6061 then they generally will not, but that is based off their lower build kit options. With the rest of the small parts, good luck trying to define mil-spec, let alone determining if the parts are or are not. Most parts come from just a few makers, and my PSA build kits have parts from the same maker that Colt has been using for years.

The cheapest option for a mil-spec buffer tube is the buy a PSA and replace the tube yourself. The second cheapest option would be to look at a Spikes or Sionics.