Lloyd
My old Lyman Cast book doesn't show any cast loads over 1950 fps. for 120 gr bullet. My newest Lyman Cast book shows one load at 2500+ fps with 122 gr.bullet. It is using about 33 grs. of RX7 powder. All the rest are running in the low 2000 fps. This is using a 26" barrel. Ken Waters shows his best cast load with 115gr Markell cast bullet, with 14.0 grs IMR-4227. I've also had the best results with cast bullets at a lower velocity.
Just bought a 24" Bullberry barrel in 30-30 Ack Imp for my T/C G-2. Can't wait to try it out with jacketed & cast. Hope it shoots as good as my 12" Custom barrel in 30-30.