80% lower Question

[Great-Kazoo]

The banned troll notwithstanding...

Just to take issue the statements that 80% lowers are always made from 6061, this is from tacticalmachining:
"These 80% AR-15 Lower receivers start as 7075-T6 forgings from the lead forge in the US and are fully machined to mil-spec tolerances. The operations left to be completed are as follows/ fire control group, trigger pin, hammer pin, trigger slot and the safety selector hole. These are our Gen2 80s and have the rear lug area cut out. This is a not an FFL item. This is not a complete receiver and still requires machining to be done. We have a copy of our ATF determination letter and our determination update stating that it is not a firearm."

I have personally machined these, and have not run into any issues (but used a small mill and end mills, not a drill press)... yes, they're hard for aluminum, but nothing my small mill couldn't handle.
Are there crap 80% lowers? hell, yes! are there crap 100% lowers? hell, yes! are there crap BCGs, barrels, LPKs, and just about every other part on ar15s? HELL, YES!!
welcome to capitalism! there will always be somebody trying to make a buck by undercutting quality.


ETA: you want a real challenging project, get some 0% forgings and look up Vader Spade's tutorial on machining it completely...

You even logic Brah ?

[Grant H.]

The banned troll notwithstanding...

Just to take issue the statements that 80% lowers are always made from 6061, this is from tacticalmachining:
"These 80% AR-15 Lower receivers start as 7075-T6 forgings from the lead forge in the US and are fully machined to mil-spec tolerances. The operations left to be completed are as follows/ fire control group, trigger pin, hammer pin, trigger slot and the safety selector hole. These are our Gen2 80s and have the rear lug area cut out. This is a not an FFL item. This is not a complete receiver and still requires machining to be done. We have a copy of our ATF determination letter and our determination update stating that it is not a firearm."

I have personally machined these, and have not run into any issues (but used a small mill and end mills, not a drill press)... yes, they're hard for aluminum, but nothing my small mill couldn't handle.
Are there crap 80% lowers? hell, yes! are there crap 100% lowers? hell, yes! are there crap BCGs, barrels, LPKs, and just about every other part on ar15s? HELL, YES!!
welcome to capitalism! there will always be somebody trying to make a buck by undercutting quality.


ETA: you want a real challenging project, get some 0% forgings and look up Vader Spade's tutorial on machining it completely...

I had forgotten that the TM lowers were 7075-T6.

I had the same experience on the bridgeport, they were completely workable, and when paired with a standard mil-spec upper, they fit with all the correct dimensions.

I also, for the fun of it, did one with the http://www.80percentarms.com drill and router jig. It took longer, and I had to make smaller cuts, but the end result was just as functional, if not quite as nice of a finish where the milling was done.

[TFOGGER]

I'll just drop this here. Assuming one takes the thickness of the anodizing into account when machining, this might be an option. Not that I'm ever going to monkey with it, as I have more commercial lowers in the safe than I'm likely to be able to build in the foreseeable future...

http://www.caswellplating.com/anodiz...ng-system.html