Hi Doc,
You should really like the MKIII for target and plinking. Unlike some of the similar pistols from other manufacturers, it performs flawlessly. I have rented a few range pistols and own a MKIII 22/45. I've used many different brands of ammo including some 50+ year old Federal and have never had a feed or eject problem. I've also rented a couple of Browning semi autos that would grab the ejected casing when using Federals but were fine with CCi's. Given a choice, I'd use CCI's Mini-Mags.
Good luck finding ammo & enjoy your new pistol,
Paul