While we know that finding fodder to put in one is difficult at present time, if and when you do find a source of .22 LR for your plinking needs, having plenty of magazines on hand keeps the rimfire fun flowing.
CMMG's .22 LR Conversion magazines hold 25 rounds of unobtanium .22 LR to sustain the fun. Durable polymer construction and compatibilty with most Mil Spec .22 LR conversion kits mean this magazine is designed for the long haul and lots of use. Assuming, of course, you can find something to put into it.
Having had a chance to run these magazines, the one complaint I would lodge rests in the loading of the magazines. Without a "slider" to help with the follower, it gets progressively more difficult to load rounds as the magazine fills up. After about the 15th round or so, it becomes a real struggle, although repeated use did break the magazine in slightly, allowing more rounds to be loaded with less stress.