Three things here about my AGM MP44 1.) What would it take to downgrade it to around 380fps in terms of parts? (it shoots around 440 right now and I want to use it on local fields that have 400 and 420 fps limits) 2.) What does it take to do something like that/ Where could I get it done? 3.) How much would it cost total, including whatever work I would have to get done on the rifle if I took it somewhere.