Any factory ammo will work fine for you. Can I ask why you selected a BAR to punch paper? Not to put down the BAR but semi autos are typically not the most accurate platform for paperpunching. They are great hunting guns and can have good to great accuracy but typically have crummy triggers that are difficult to modify. To get best results for paper targets reloading would be the best way to tailor a load for your BAR. Note if you decide to reload you may need "short base" dies for a semi-auto to cycle correctly. You would also likely have to keep charges to mid levels to get consitent pressure to cycle the action reliability. Others with more experience with these rifles may chime in. My experience is limited to a few that I have shot over the years. Just to end on a positive note my friend had a BAR .270, that gun shot 1/2MOA with Winchester supreme ammo 130gr I believe. I would say if you are shooting Factory, experiment with different manufactures ammo, if you find ammo the rifle shoots well buy five years supply with the same lot #
Good luck with your new toy .