I think you're right on the upper side of being to stout for the 30/30 Contender velocities. The Noslers minimum impact velocity is 1600/1800 FPS and I'm sure you could push that pill to 2100 over the top of some Benchmark or 8208 powder. I would see how they shot in your new barrel and then do some bullet construction integrity testing. A lot of people really like the plain o'le Ballistic Tips in their 30/30 T/C's. I also don't see why the Berger Bullets wouldn't do well for you. . .they expand at your T/C velocities. I haven't shot the Hornady Flex Tips from a pistol barrel, but they don't do so well on critters out of a 20" 336 Marlin rifle. They're pretty accurate, but lack the on game performance.