I ran some 208 grain amax last night and they didnít do a good job.
What specifically do you want? Do you want a subsonic round, or a super sonic round.
If you want a sub, you have to remember a big factor. In the 300 blk out subs, you are shooting a round with about the same bullet weight and speed as a 45 ACP hand gun. A 208 grain sub at 1000-1050 fps is about the same speed as a 230 grain 45 bullet doing 950-1000 fps. And the blk out 208 A-max isn't expanding. So, there's not much energy there.
If you want a pig to go down and put as much energy on target, then the super sonic ammo is what should be used. Out of an SBR barrel, I would recommend the 110 V-max or any of the 125 grain hunting bullets. They provide good expansion and good penetration.
Also, I look at the subs as a golf analogy- Drive for show and put for dough. Drive for show with the subs, and put for dough with the supers. The subs are great at the range for being quiet and fun to make you giggle about how quiet they are. But when it's time for hunting, use the supers. And the subs give you no real "quiet" advantage. Once you get into a group of pigs and the first pig is shot with a sub, they all take off running any way. They act the same way with the supers. I can shoot any bullet I want in the blk out, and I run the 125 grain options for hunting. They work very well.