Beer guns and elaborate picnic faucet contraptions are a complete waste. Seriously, just jam a 1-foot pice of 3/16" beverage tubing into your kegerator's faucet and bottle away. If it doesn't fit, just shave off a little chamfer on the tubing's edge. Turn the co2 pressure down, and hold your bottle in an ice bath while filling. No foam, and virtually free. It's really that easy.