Reading the manual for the P90DC and see a nice feature. Unlike a 1911, you can load a single round direct in the chamber. I think the magazine is supposed to be out to do it, but just stick it in the chamber and drop the slide. The ejector has a ramp on the front that makes it engage the round without causing damage.
I just realized I now have 5 45s!
Charles Daly Field 1911A1
Sig P220
Ruger P90SD
S&W Chief's Special
Bond Arms Rougneck in .45
Outside the revolver department, I only have two 9mms and two .32 ACPs. Definitely biased towards 45s!