I don't. They use TAC for Mk232 77gn Match in 5.56. The ML118LR load from Lake City is RL-15 with a flash suspressant added. I don't know if that gives you a place to start or not.
What ever the powder is in BHA ammo you will not be able get; because it is a non canister powder.
The current Federal powder is non canister grade of RL15, again you will not lay hands on.