Alexander Arms 20" Entry Complete Rifle

[A1Vixen]

I bought a AR15 from Alexander Arms, will get it in approx. 1 month.
Who has experiences with this AR15, what will be the heaviest bullets I can use with 20" and 1:9 twist barrel for 600-800m?

It will come with the AA factory stainless barrel. I will change the trigger (Trigger Tech) and the but stock to a Magpul PRS.

Can't find lot of information or reviews about that rifle, if someone could share some experiences this would help a lot.
Are the Lapua 108g bullets too long? I have 500 of them and Ramshot Tac as powder at home for my other bolt action project.

[Sticks]

Your 108's are fine, the 123gr class of bullets give you the best BC

Hornady Black 123gr ELD, and American Gunner 123 BTHP are the go to factory ammo for target, and 123 SST for hunting.

For hunting you can go up to 129.