Any you guys have SPR/SAM Mk 12 Rifles?

[Patrick Floyd]

I want to make a S.P.R/S.A.M Counter Sniper upper, for my A2. Any you guys have any ideas for me? Such as barrel twist,optics, and hand guards. Also have you guys shot any Black Hills MK 262 Mod 0 77 gr rounds? What would be a good load?

Thanks you guys

Patrick Floyd:50_cal