Livbucks, the barrel you are shooting the bullet out of is mainly for roundballs or conical bullets!! The stablization of a powerbelt is better in a barrel with a faster twist. I would suggest shooting a Hornaday 385 grain HBHP. I shoot that through my 1 in 48 barrel, and have consistant groups. I use Triple 7, fffg form. GOOD LUCK!!