I hate to sound like a fan-boy for Rock Island Armory (though I am!) but they have a combo that lets you switch between .45ACP and .22LR on the same frame. Just take off one slide and put on the other, stick in the appropriate magazine and off you go! It's called the XT 22/45 Combo and lets you build muscle-memory on a 1911 frame while gaining sight picture skills yet paying pennies-per-shot in .22LR mode. No, you won't get the same recoil action or muzzle lift with the .22 rounds (unless you get someone to whack your hand with a rubber hammer when you fire the thing!), but it still lets your finger feel the same trigger characteristics and your hand feel the same grip and control locations as the big-bore would. In my estimation (and that of a whole bunch of others) there is nothing like the feel of shooting a .45 1911; it is totally unlike the feel of any polymer .45 and this way you could get cheap plinking and the option of tossing major lead when you want to. Check it out, my friend; you won't be sorry!