Wow, someone was really digging around the archives to bring this one back to life.
I can't understand why someone would want to have somehting like an HK94 or any handgun as their only weapon. Yeah, they might have a certain cool factor to them, but you would simply be WAY too limited with such an impractical gun.
The AR15 is really the only way to go if you must press a single gun to perform a variety of chores. Think about it. With a single lower receiver, you can have anything from a .22LR to a .50 BMG and practically everything in between. It's modular design lends it to seemingly endless alterations, modifications, and configurations. Need a rimfire for plinking or quiet small game hunting? Got it. Need a handy carbine? Got it. Need a handly little 9mm or .45ACP gun? Got it. Need something with a little more punch for deer or other big game like a 7.62x39, .300 Whisper, .44 Mag, 440 Corbon, or .50AE? Got it. Need to reach out and touch someone/something half a mile away with a .50BMG? Got it. I'm also certain that it would not be any big feat to build other single shot uppers in .308, 30-06, .300 Mag, any any other typical chambering. Could probably even come up with some of double barreled shotgun upper receiver, too. Face it, no other gun on the planet offers anywhere near as much versatility as the AR15. Is it any wonder that it is so popular?