The good news is I think I figured out why my XDM has been intermittently failing to lock open on the last round. It would happen sometimes, no matter which of the five magazines I had in. Apparently, occasionally in recoil on the last round, my right thumb is brushing the slide release. Now I just have to figure out how to alter my grip a little so that doesn't happen and I still have a good grip. (I think I'll try changing to the large backstrap.) In other news, while I was working out the above issue, I was also shooting my Ruger 22/45, and it began keyholing. It could use a good cleaning, and I'll see how much lead I get out of the barrel.