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[buckallred]

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[tujungatoes]

For the purposes of an AR it really doesn't matter. If you're machining an 80% lower the 6061 will be easier to cut as well.

[Sunday]

7075 aluminum is approx twice as strong as 6061.

[M1NM]

Mil spec is 7075 not the softer 6061 which has less tensile strength. In the whole scope of making your own 80% the expense of buying the best lower is miniscule. I've heard most of the 6061s come from China - don't know how true it is but seems reasonable.

[bandook]

Just for the record, those polymers lowers are reinforced. Some better than others.

[DS8]

I went with 6061 because its not a part that gets any stress and it was easier to mill

[1flhtk4me]

I've heard most of the 6061s come from China - don't know how true it is but seems reasonable.

All depends on what the mfg's purchase.They can save money buy buying imported materials.
There is plenty of USA made 6061 and 7075.

[totalloser]

An advantage of 6061 is that it is very very weldable. Not only can it be welded, but it can be retreated to t6- even the weldment. 7075 is damaged after welding and cannot be resurrected to it's former glory.

[Lostsheep]

I am not sure why you guys think 6061 is easier to mill than 7075. Both are really easy to cut but I have to give the advantage to 7075; 6061 is a gummier material and can build up in your cutters.

More important than which alloy you choose is to buy from a reputable vendor. I can not speak highly enough of the work that I've seen tactical machining do.

[yari]

If you have to ask why question it later? Tm forged 80s are top notch. If you want to go fancy billet you're too late my 7075 80$ are sold out

[JAE]

I like the way the forged lowers look. More classic. The billet ones are kind of blocky looking and don't match the uppers I own as well. That said some guys would consider this an asset. So choose to suit your taste and be happy.