Originally Posted by unclebear
I don't know if this would work for hitlers germany over there on the west coast but I know that some mags in canada are pinned to 5 rounds
I wasp going to say the same thing. As much as it would suck, you can load ten rounds into a magazine, with where the follower sits and then make a small hole just below it through the side wall, then put a rivet into the magazine. Then if/when you leave the state, you can remove the rivet and seal the hole with some JB weld.
There also what everyone else said, store the 20 rounders you've got and then buy some 10 rounders.