Question for Jim: If an airgun delivering 11.5 ft.lbs. in .22 has the barrel changed to .177, does this alter the ft.lbs. output? A simple question, but I bet not a simple answer. Already looking forward to the next issue of Airgun World. GRAHAM WILLIS
Jim’s reply: Comparing like for like – testing with similar pellets – changing the calibre from .22 to .177 most certainly will have an effect on muzzle energy. It will reduce it, because the .22 is inherently more energy efficient. The exact amount by which the energy will reduce depends on the type of rifle (PCP or spring) and, in the latter case, on the specifications of the rifle; piston stroke, cylinder diameter, spring energy and preload, seal type, transfer port dimensions and lost volume. In the case of the 11.5 ft. lbs. .22, the muzzle energy drop might be in the general order of a foot pound or two. The only way to be certain is try it and see. - Jim Tyler
Jim says swapping barrels from .22 to .177 will drop the airgun’s muzzle energy.