I just got an email about billet lowers at Centerfire for $79.95 +$9.95 shipping. That seems incredibly cheap for a billet lower - does anyone know anything about them? Where they’re made, type of aluminum, etc?
I just got it too. Had the same questions…
I’ve heard of them in 7075 aluminum, but not sure of Centerfire’s product.
its a TNW lower.
and the TNW upper they have on that sight is 6061 T6 so i assume the lower is 6061 T6 too.
Never heard of TNW. Good? Bad? I’d be in for a billet lower for that price.
I got the same email and had the same questions.
The forged version, which is discontinued but still shown on Centerfires website, is 7075 in the description
It says you can upgrade to the machined version for the same price but does not have a link and I could not find the billet machined version on their website
Which begs the question: is a 7075 forged lower better than a 6065 CNC machined billet? You can get either for the same price.
Forging requires a precise recipe of heat, quality material, good dies, and operator competence. CNC requires a recipe of proper tool feed speeds, appropriate radius callouts, quality material, sharp tools, and operator and programmer competence.
I detail that to show - either way, you can still make junk if someone isn’t careful. Forgings can be struck too thin, leaving little material in places after machining. CNC can create stress risers, cut too hard and fast literally bending the billet in the jaws, and therefore be out of spec.
Out of spec parts for a tier one customer might be great quality parts for an aftermarket vendor. Or overruns deliberately build for profit out the side door. It’s really hard to tell what goes on, since nobody wants to say.
Lot runs vary, too. Someone’s part from Sept 2007 may be better or worse than todays.
If anything, 6065 was known to corrode in extreme conditions - like wading through tropical wetlands. In a temperate climate - not a problem anymore than a barrel. It was original AR spec according to some sources.
When someone buys, assembles, and shoots one for a while, we might know - about that one.