Ben, Maven, Brad, Jim all said what I would have. No more than eight grains of Unique for that. Also, watch the Marlins for leading in the first inch of throat with PB bullets, and if you see that, soften your alloy a bit or bump the powder burn rate and pressure.
Some reservations about the Unique comment, though it's tough to argue with a CBA competitor on opinions of accuracy. I think people confuse powder position sensitivity and improper handling or loading techniques with "accuracy variances". My experience is that if you can't find a competitive load with Unique, sell the rifle.