some semi autos (gas guns such as M1 Garands, M1As, etc) need a specific load because of its pressure curve. (as evidenced in Hornady's reloading manual listing for M1 and M1As.) I'm not an expert on this and whether it affects a BAR, but it's just a heads up. Your best bet is to call Browning Tech support or Nosler Tech support to check.
Also-Hornady Light/Heavy Mag ammo and Federal High Energy ammo have safety disclaimers on them stating that they should not be used in semi-autos for that reason.
now the BAR doesnt have the operating rod issues that the Grarand has so you shouldnt have to keep it within those limits. but to be safe you shouldnt use real slow powders and you should avoid max charges. i could be wrong but im pretty reasonable on gun stuff.