Quote Originally Posted by NickG View Post
S I now have an s200 barrel in my possession, so how long do I want it , I hear longer is better with springers , I can go 50mm longer than standard TX maximum, as I am making the shroud myself any Ideas ?
It depends what you are trying to do and to a certain extent the design of the springer. If you go too long for the internal design of your springer the pellet will slow down too much in the barrel and you will loose energy and efficiency. This may lead to you increasing preload or spring rates in order to recover the energy which will alter the feel of your gun. Short strokes tend to need shorter barrels to achieve maximum energy compared to long strokes.
If you are not concerned with energy or energy efficiency then you have to think about shot timing at pellet exit compared to what the gun is doing and how this will vary from pellet to pellet. This will effect pellet dispersion at the target. In addition there is also optimal barrel timing based on longitudinal shockwave theory though I am not sure how relevant this is to air rifles.