Odd, my first 1911 was a Star in 9mm and it never jammed. What I didn't like about that gun was how the safety was too loose and didn't engage or disengage with a definite click after some initial resistance, the way my Springfield 1911 does. For that reason alone, I always carried "Israeli style" with no round in the chamber, hammer down, safety disengaged, and only once did I have to draw and shoot in an instant (A wild animal was startled by my cat sneaking out of the back door as I was taking out the garbage, and attacked her
). Because I drilled drawing/charging as a single motion, I was able in a split second to shoot the wild animal before it could do any damage to my cat. Immediately after that, I invested in a Ruger P-series 9mm.
PS: I think the Jam-O-Matic nomenclature seems to have originated with Kimber a few decades ago, and the fellow I knew who was frustrated with it junked all his Kimber mags & switched to Wilson Combat, and presto! Problem solved!