Please leave a comment why you chose the manufacturer you're recommending! Looking for best quality, not taking price into consideration.

Michigan hunter new to the AR-15 game and will be building my first AR!

Brands I've found in my research that make .450BM uppers currently:

Windham Weaponry
Bushmaster
Trident Armory
Franklin Armory
Great Lakes Firearms
BartZ Manufacturing
Tromix
Alex Pro Firearms Armory
Next Level Armament
Radical Firearms
Gryphon Trading LLC

IMO the best quality, best prices, best warranty, best customer service, and fastest shipping is TROMIX.

TROMIX has been in the big bore AR game longer than all the others combined.  He was turning out big bore .458S in 2001 and other big bore calibers well before that.  TROMIX is the KING of big bore ARs, period.

Thanks, haven't looked into them much so far, will check them out now!!

We have had excellent results with the V7 Weapon Systems 2055 lithium aluminum uppers. In our high speed camera tests, they did better than other brands when it came to barrel flex during the recoil cycle. Units like the magtac magnesium uppers flexed significantly. Normally this doesn’t matter unless you’re chasing precision sub moa groups.

Another nice benefit is the V7 uppers are lighter than most uppers except the weaker magnesium units. The receivers faced well and did not require much work on the facing tool/lathe to true up the barrel mating surface.