Fletcher, I'd set the BOSS for any one of the 150 grain bullets used. You would still have to test it even if Browning sent you stuff they tested with the ammo you want to use.
I wouldn't fret over having the exact load spec'd to your A bolt BOSS by Browning. With all due respect Browning for all the great stuff they've done, it's impossible for their BOSS system to work the way they claim it does. They claim the bullet shoots most accurate when it leaves when the barrel's straight. No barrel's straight when the bullet exits. They all wiggle and whip quite a bit. Check out this web site:
'Twas proved over a century ago that if bullets leave as the muzzle axis is swinging up and almost before it reaches its highest angle, best accuracy happens. That compensates for the muzzle velocity spread; slower bullets leave at a higher angle than faster ones.
Browning does not state which way the barrel has to be moving when at some point it's straight out. it's either swinging down or up; one's not good and the other is.