Logic/experience. Many of us, myself included, wasted thousands on things that didn't work out. So far my favourite and most effective setup is a CQB M4 properly modded and upgraded. It's so versatile I can use it anywhere, but it can put high volume of laser-accurate rounds over two hundred feet away. Indoors it's certainly bigger than pistol, but the accuracy and stability makes effective. I always carry a reliable sidearm though. Going into very tight spaces (like a room) it can be a lifesaver. That being said, for killing multiple enemies and keeping heads down nothing beats an assault platform.
ďREALITY IS LIKE A STONE. TO MANY ITíS HARD AND COLD, THEY CANíT HUG IT OR EAT IT, IT ONLY FRUSTERATES THEM AND DOESNíT DO THEM MUCH GOOD. TO OTHERS ITíS STRONG AND DEPENDABLE, YOU CAN BUILD WITH IT, BUILD UPON IT, OR WORK WITH IT, ALSO USE IT TO SMASH PEOPLE IN THE FACE.Ē