I have a P90 I bought new end of 2010. I have shot 45 auto in my 1911 for years. I usally rack and lock the slide back push in the clip and hit the lever and it loads. On my P90 it will jam almost every time. I called Ruger and they told me not to do that. I must manually pull the slide back and release. It does work with out problems. My son has a much older model and he told me he always loads the first round the way I described. After a a mag is empted and the slide is locked back he always just hits the lever and releases the slide. His never jams. It seams to me if I am in a competion and want to releoad quickly, I will loose time if I have to manually pull the slide back to get it to feed. I welcome you comments.