I've seen some sites with mods show the Crosman 2250 single shot rifle with a longer barrel claim the gun will go from 495fps to 550fps. Any truth to this? I might actually consider extending my 1077 barrel then to get some more fps out of it if this is true. Yah I know it'll slow the pellet release time but a bit more fps is good when you're going after Joe Rockhead squirrel. If I can tune my gun to 550 fps then use a 12-16gr .177 then it'll give more mass on that squirrel if the 16gr pellet can slow the fps down to 495-500 fps then.
http://www.thomasadams.org/airguns/modified_crosman_2240.htm
Glooko
..."In Glock we trust"