I recently bought a tippmann m4 and was looking to upgrade its accuracy. I was looking around but I couldn't get a definitive answer on how to upgrade it. I saw a couple of home made fixes but I kinda want to get something that's more official. I wanted to know which parts were proprietary to the gun. Also I heard that some barrels didn't work that great with it so I was wondering what barrels would be the best to get.