I have a chart I got off the internet showing FPS/FPE per pump on a 392 using a 14.3 gr Crosman Premier. That gives me a decent baseline for what my rifle is doing, but as we all know, even slightly varying pellet weights and FPS can have a large affect on actual FPE.
Currently, I'm shooting 18.21 gr Crow Magnums. If I use the listed chart, then I'm putting out about 13.05 FPE @ 5 pumps (568fps). Now I know that's wrong, because I got the 568 FPS from the chart which is using a 14.3 gr pellet, a pellet almost 4 full grains lighter than the Crow Magnums which by reason have to be going slower.
What I'm asking is does anyone have any chronograph readings for a 392 with 5 and 8 pumps using an 18.21 gr pellet? I'm looking to get a more accurate idea of how much power my rifle is putting out.
Currently, I'm shooting 18.21 gr Crow Magnums. If I use the listed chart, then I'm putting out about 13.05 FPE @ 5 pumps (568fps). Now I know that's wrong, because I got the 568 FPS from the chart which is using a 14.3 gr pellet, a pellet almost 4 full grains lighter than the Crow Magnums which by reason have to be going slower.
What I'm asking is does anyone have any chronograph readings for a 392 with 5 and 8 pumps using an 18.21 gr pellet? I'm looking to get a more accurate idea of how much power my rifle is putting out.
