What's going to make any magazine hard to seat when the slide is locked back, there's nothing to interfer with it seating, no reason to slam it in, just insert it until it locks in place. As a LE firearms instrctor, we teach to give the magazine a little tug to make sure it is seated, then manually release the slide by pulling it fully to the rear to get all of the spring that you paid for, and let the slide run forward to reload the gun. If one hand is all that is available, one can use the slide stop to release the slide, or a boot heel , or whatever else is there. Think about reloading an auto with one hand while you slam in a magazine. Auto pistols are not designed to slam and close, it's unsafe at best and could lead to damage to your gun and magazines. Bob!