I have owned and operated 9MM 1911s for quite a few years, to include multiple Colts, Kimbers, Dan Wessons, Springfield and STI. Within my humble experience, the later 9MM 1911s with the factory, or custom fitted, ramp style barrels tend run reliably with any quality magazine. I've only owned one factory 9MM 1911 with ramped barrel that did not run reliably as received. My most used 9MM 1911 magazine is the 9 rd. Metalform "Springfield front ramp" type. This is the magazine Springfield and STI provide with their guns. Excellent choice IMHO. It is different in concept from all others, and the one I wish had been available many years ago when I was trying to get Colts, with the traditional non-ramp type barrels, to run reliably...ymmv