I think we have been over this about 500 times
. Do your research before you buy it not after . I see alot of people come on here and ask how their Brand X is that they just bought .
NO, NO, NO NO NO !!!!!!!
You do this before you buy it not after
99.9 % of the Mil spec forged aluminum lowers and uppers are all the same , there are about 6-7 forges out there that make forged lowers and uppers for well over 300 US companies , they just have different roll marks on the side .
Want a good solid build ? Then figure out what you want to use the gun for , Plinking, target, or Battle rifle . Are you going to be using it hard as in a 1000 + rds a weekend every month ? or just every once in a while 500-1000 rds per year.
DO you need a precision trigger for shooting off a bench or will a mil spec trigger do what you need?
What ammo are you going to shoot, what ever is available on the shelf or precision reloads that you reload your self ?
Do you need a chrome BCG or will a quality brand BCG work for you ?
What length of barrel do you need or want,
Do you need or want a free float barrel ? If so how long of hand guard to you want ?
What gas system ? There are 4, pistol, carbine, mid, and Rifle length, pick one its not that big of a deal .
Buffers . If any doubts get a standard buffer and spring unless you are using a fixed stock then use a rifle length buffer and spring
Are you buying this gun to use or like to have it nice and new looking all the time " Safe Queen" ?
All these questions you should answer your self before ever coming on board with tons of questions . Its not that people wont help you , its that you can answer most of them yourself if you just answer the above questions.