My son sent me three 10 limited (long) mags today and I decided that since they only take 10 rounds, I'll cut them down to size.
For those of you who don't have a band saw or table saw.
Or the lazy ones like me who just can't bring yourself to dig your saw out from under a pile of rubble.
You might consider using a miter box with some big clamps, furniture or C-clamps, and a hacksaw.
Its very easy to make clean straight cuts with the mag clamped into a miter box and a hacksaw.
Here's a couple or three pics of my cutting up a mag to show how I did it.







You can see how the hacksaw cleanly cuts the mag body and with it clamped into the miter box there is little or no chance of making anything but a nice straight cut.

Now I just have to figure out how much to cut the spring.
Reading through this thread to see what others have done I think I'll start with cutting it in half and work down from there.