9x19 wrote, "Early Ruger P-85 mags (P85,P85 MKII; (Serial No. 304-69999 & Below)) are not interchangeable with later model P-9s P-89s, 93s, 94s, and 95s." I can't really disagree with the fact that there
is some difference between the two but am not sure the term "not interchangeable" is necessarily an absolute. I once had a P93 and called Ruger about this. They told me the same thing and said only that they would not "guarantee" the older mags would work. At the same time no one I ever talked to or any thread I read indicated anything but success in using the older mags in the newer guns. I think there was a small change to the locking notch but am not sure exactly what is different. At any rate I eventually sold the P93 and the question was moot. Later I bought a P95 and acquired some older mags and tested it out for me own self. To date I've used at least a dozen different magazines, some pre-ban newer models with the plastic base, some older metal-bottomed mags, and some Mec-Gars and can find no difference in reliability or function. All have worked perfectly. I suppose it is a buyer beware situation but personally I no longer worry about 304-69999 and below or 304-70000 and above although I am certain there is some difference and Ruger has their reasons for noting the difference. At any rate, any magazine should be tested with the pistol for which it is intended. On a side note, I did once try a .40 caliber mag loaded with 9mm as many have suggested. It "worked" but I would not rely on such a gimmick personally. It didn't hold the 9 at the proper feed angle at all even though the Ruger gobbled it up anyway. Not my cup of tea. Just my experience FWIW.
