There's a sizeable group who will wander into these forums and say that they've never had a dud in .22 Mag in decades, but IDK if that's all been in handguns or all in rifles, I tend to believe that handguns don't have the force that rifles do, but regardless I've had duds in .22 Mag and light strikes.
I don't find .22 Mag to be more reliable than .22 LR. The belief among that group that does think .22 Mag is more reliable is due to it costing more and thus that equates to better QC and that is not the case; the increased cost comes from the bullet used costing more to manufacture and using more brass for the case.
I was curious enough a year or so ago that I asked CCI what they do differently between .22 LR and Mag, if there's any change at all in the priming between the two that might cause .22 Mag to be more reliable and CCI said the difference is they use a different primer compound (probably a magnum type primer that burns hotter) and more of it for the larger powder charge.
That's it. They use the same tools/machines to make the cases, prime the cases, and load them and I suspect the testing/QC criteria is exactly the same as .22 LR.
Between premium .22 LR like CCI Velocitor and Federal Punch, I don't think the reliability between those types of ammo and .22 Mag is any different. Now, bulk packed crap .22 LR from Remington is of course going to have looser standards and won't be as reliable as .22 Mag, but it also won't be as reliable as premium .22 LR either.