I also just finished a small "walkaround" rifle on a Charles Daly Mini which was the 22-250 action. These have the longest magazine of the bunch and a .473 bolt face.

I have been kicking this project around for a few years. My intent was always to make it a child's or woman's deer rifle. I played with the action and found that I could modify it to feed 100 gr factory 250-3000 ammo. The magazine box was opened to the rear, the rear bridge was opened up and the bolt stop was ground back. While this worked, it was really tight and would still be limited to 100 gr bullets. I wasn't about to start grinding on the feed ramps for more space, given the lug size.

After tinkering with the magazine, I found that by carefully blending the side box into the recess in the rails and beveling the edges of the follower so that it slid smoothly, it would feed 6BR rounds. If positioned in the forward part of the magazine with everything smoothed up, it would hold and load three down.

The barrel is a No 1 Douglas (looks bigger on this action) and the stock is a tan Bell and Carlson. The wole rig would be less than 7 pounds with a more appropriate scope, but I had this one and want to try it, which I haven't done yet.

While this is not much of a custom, I wanted to show it so people could get an idea of what the action looked likewith the maximum maximum length. In the second picture, you can see where the rear bridge is cut to to match the magazine when moved all the way to the trigger boss.