Not very good - MDT Metal .22-250 Caliber 10-Round Rifle Magazine

To be clear, it loads rounds in to the chamber just fine, and hold rounds in the mag once inserted just fine, but here is the problem, loading rounds into the magazine, there is a very large (almost 1" of play), it's clearly not designed for this caliber, you really need to be careful and think carfuly how to place them without risking a malfunction while shooting.