I'm no engineer so don't flame me. I have a PS90 idea I wanted to float. If you look at the bottom of the magazine there is a small cup that fits into a nipple on the receiver just forward of the well(loading chamber). When you depress the Magazine catch you have to pick up on on the magazine to get it out of the well to change mags. Why couldn't you put a spring inside of the cup of the magazine or around the nipple, so that when you depress the magazine catch the mag would pop up?