. If you take apart the barrel and breech mechanisms you will find that there is a lot of movement between parts. Especially where the barrel fits into the outer sleeve of the breech. By increasing interference via the use of white ptfe tape and epoxy all the air leaks are closed and therefore increasing the velocity of the bb leaving the barrel. Some barrels, ie the king tiger, there is also a small hole drilled in the barrel to allow air to escape behind the bb as it travels down the barrel. This I imagine is done to lower the FPS, making the model safer. But at a cost of much shorter range. Wrap tape/or seal with epoxy to increase muzzle velocity further. Its amazing how much more range you can get which gives you the edge in a bun fight 
, especially if your short barreled Sherman is getting a splapping from said KT 
. You can also take advantage of the extra velocity by using .20 bb’s instead of the supplied .12g ones, for a more harder hitting round. Best not to go any heavier though, or your opponent will get upset when pieces of his beloved get smashed off during a strike. Something like a .40 bb would be like throwing golf balls across the battle field. As soon as I get the chance I will chronograph before and after barrel velocity to see just how much more fps is gained, just out of interest.Now I wonder, what would happen if I changed the main spring in the mechanism and used a higher torque motor?????
