Ok so my marker loooks just like a M-16 gun.
see here: https://encrypted-tbn3.google.com/im...IqWseJfpzBuLdr
It has a 12" barrel with a co2 tank, and some cheap tippmann electric hopper. I want to upgrade my barrel to a 18" or 20". Which one would be best, and is there a specific one i should look into to improve range and accuracy?