I have not shot the 30/30 in a 10 inch but in the 14 inch it is very gentle with handloads and factory remington ammo. As far as the 223 there are guys on here with much more experience then I. It seems like the 5.56 military stuff is in a steel case and that makes the walls thicker creating more pressure. I may be wrong but I know guys say not to shoot that stuff in the contender due to pressure.