https://www.ar15.com/media/mediaFiles/70232/Ballistic_Advantage_556_75Inch_barrel-1653119.jpg
https://www.spicetac.com/ballistic-advantage-7-5-556-ar15-pistol-barrel-modern-series/

https://www.ar15.com/media/mediaFiles/70232/Aero_Precision_Scope_Mounts-1612136.jpg
https://www.spicetac.com/aero-precision-scope-mounts/

See the guide to finding ammo online!
https://www.spicetac.com/best-places-to-buy-ammo-online/