If I remember correctly black hills originally wanted the cannelure on Sierra 77 OTM for the military, and Sierra did not want to do it, thinking it would affect accuracy, but apparently it does not.
https://charliescustomclones.com/black-hills-ammo-5-56mm-77gr-tmk-red-box-tipped-ammo/?utm_source=instocknotify&utm_medium=email&utm_campaign=instocknotify
Looks like they’re getting a big shipment around July 8th. Haven’t seen black hills 77gr TMK in stock for what seems like years…