+1 on starting with a lower powder charge. If you're going to use the Powerbelts- I'd start out with 80 grains of powder and see how that does. Based on a lot of testimonials, I'd keep it under 100 grains of powder if you're going to use Powerbelts.

My hunting buddies shoot Traditions - they use 80 or 90 grains of Triple Seven and a 240 grain Hornady XTP - really good accuracy and lots of dead deer. You could bump up the powder charge if you're using an XTP too, but I'd still start low and work your way up to see where the "sweet spot" is for your rifle.