Some people have poor experiences with Nickel plated brass. Some of the rifle calibers are horrible with the coating. I have had nickel cases in .243 Win. .257 Roberts and 7x57 that have worked out excellent for me. The 7x57 cases have been reloaded so many times the nickel has finally worn off the case but the cases are still good. Yet a friend of mine had cases in 30-06 that did not last very long and were splitting on the second and third firing. But even with nickel you still have to lube the case when reloading and make sure that your dies are clean as you can scratch the nickel finish just as easy as you can brass with a dirty die. But in a carbine I think Jim is right. Plus you have to still trim and measure each time you reload so if there is a savings with the nickel plated brass in 30 carbine I have not seen it.