Archie,
I just happen to have a T/C Contender 24" rifle barrel from the T/C Custom Shop, chambered to the 30-30 AI. I like it a lot.
Velocities with 150g bullets run 2,700-2,800 fps. and velocities with 125g bullets run 2,800-2,900 fps. and I get no signs of excessive pressures.
I have copys of Mr. Ackleys books and they lists his velocities.
My rig is very accurate, as well!
The best group to date is the 125g Nosler BT over IMR 4198, which gave up one group of .25" @ 100 yds.
Buffalogun
