Regular loads in one of my Savage FP's are easy to spin apart the Dogtown's.
Savages are famous for really rough bores, which could be the cause of your problems.
Also, what grain Dogtowns are you using? Midway claims a 4000 fps limit, and a 223 could get there with the 34 grainers.
I've never had any problems with light plastic tipped bullets in fast twist 22s, and that includes a decent pile of 223s and 223 AIs, a 220 Swift, and a 22-6.
