MMM, it would be nice to be able to interchange magazines, but in 45 I'll have to agree XD doesn't make anything that small, especially in 45. How small do you want to go? Beretta is coming out with the "Nano" and you can be assured it will be extremely reliable which would be my #1 priority. I've only owned Beretta's so I'm not qualified to suggest anything else, but in my lengthy experience with Beretta firearms Beretta=Bang when you pull the trigger. I watched the official review from Beretta and they claim they have been engineering the "Nano" for awhile and the pistol is based on a 40cal frame and is promised to be extremely reliable in either 9mm or 40cal. I believe it would be a very good choice as a reliable bug gun, especially if your life is on the line. I've heard Kel-tec and Ruger make extemely reliable bug guns as well. Just my 2 cents.