I picked up this 22 rifle as a project a few years ago. I have up and running but one problem with it was the inner magazine tube was missing. Numrich said one for a Nobel 235 would work and it does but it is one shell to short. Because the shell lifter can't reach the magazine follower the last empty shell casing stays on the bolt instead of being ejected. I think the best way to solve this problem is to shorten the outer magazine tube. The tube has been split and repaired in the locking notch area and a correct inner magazine does not exist. My question is how do I determine how much to shorten the outer magazine tube?