Thread: Calculating velocity

Hello, I'm new to reloading, but I have worked up a new load for my 6.5x55 using 140gr sst's. Groups are under 22mm consistently.

Is there any way to calculate the velocity from knowing 2 different points of impact at 2 different ranges. I think it is easy if I had my rifle zero at 100 but I didn't think to do that at the time. So the data I have is at 100y my impact was 4 inches above point of aim, and at 165y it was 5.5 inches above. Rifle is ruger with 22inch barrel bullet is hornady sst bc .520.

I have been banging numbers into a ballistics calculator for ages trying to get the points of impact to line up and the closest I can get is a velocity of 2700fps sighted in at 291y gives me a 100y point of impact at 4.45 inches above and 165y point of impact at 5.46 which is pretty close. Is there an app or programe you can enter 2 points of impact without knowing your zero the one I have been using our need your zero range.

Thanks if any one could check this and let me know if I'm on the correct track would be much appreciated.