"...with off the paper MOA..." If it won't shoot a group at 100 yards with whatever ammo you're using now, match grade ammo won't help. You should be getting 3" to 4" or so groups, at 100, with any decent milsurp ammo. How's the barrel? TE and MW?
Federal loads a 168 grain Matchking .30-06 in their Premium Gold Medal brand. Haven't a clue where to get it though. Won't be cheap, but if a retailer's distributor has it they can get it.
You're best reloading your own though. 168 grain Matchking(or any other brand) bullets out to 600 yards, 175 grain Matchkings past there. Both using IMR4064 and regular large rifle primers.
"...150 gr Full Metal Flat Bottom
50 gr IMR 4895 M1 ammo load from WWII..." That's .30 M2 ammo. .30 M1 ammo used a 174.5 grain bullet at 2640fps. There's no guarantee that 50 grains will shoot well out of every rifle either.