According to my gunsmith the rechamber from 30-30 to 30-40 was very easy. He had it done in just a couple of days, The worst part was waiting for the parts to fix the action. I purchased the NEF from a friend for $50.00 becuse of the condition of the stock and broken hammer, firing pin, trigger,trigger guard. Now it's all back together. Wish i could post before and after pic's but no picture program in this computer. Now just have to reblue and polish, mount scope, and build up a load for it.