I'm brainstorming a smidge. I'd really like a custom built 9mm Single Stack, and I'm also thinking real hard about a 9mm Single Stack Open gun for Steel Challenge and West Coast Steel use. The idea I have in mind is to build two identical lowers, but have one built with a Single Stack upper and the second built with an Open upper. This way, at least as far as the frames are concerned, one gun could serve as a backup for the other gun and would make for a quick and easy mid-match swap out in a