Way back when, when PA started their primitive season you could only use flinters and PRBs. Most of us used T/C Hawkens, a couple had Renegades and even fewer had Lyman GP Rifles. The Lymans tended to shoot the PRBs a bit better with their 1:60 twist then the T/Cs. But the T/Cs with the 1:48 twist held their own. If I remember correctly, I used to use .015" patches and a .490 RB with a charge of 100 gro of FFFg.