It is not out of place for the nose of the bullet to dive down first, as the slide contacts the top-rear of the rim of the cartridge, to begin the feeding process. If the ramp in the frame isn't quite right, or if it's been butchered by a "wanna-be" gunsmith, it can also cause the problem. And yes, it could be the mag too; particularly if it's one of those triple-K counterfeits.
Something else needs to be brought up here... First written about by Jeff Cooper in Guns & Ammo in 1976. It's a thing called "grip-sensitivity". (Small Kimbers and Springfields also display the problem in certain shooter's hands). It's not necessarily due to limp-wristing, though it can be. Some "iron-grip" dudes have had the problem too. It might be due to the shape of the shooter's hand bones, or maybe even the way muscles in the forearm react to recoil.
In some cases I've witnessed, a Detonics that could be shot upside down in my left hand, and even upside down between my legs, would not function properly in the firmest of two-handed grips in the "grip-sensitive" person's hands. If this is the case, even good magazines won't help you. Sorry about that, but that's just the way it is.