Thread: Barrel chop

Originally Posted by dannyb

If he's using an optical chrono it could be anywhere + or - 100fps depends on lighting conditions....optical chrono's drive me nuts with their inconsistent velocity more than once I've gone out same load different days in different conditions (cloudy vs sunny) and got different velocities due to using am optical chrono, shot same poi just got different velocities due to lighting being brighter or darker. If you don't know someone with a Labradar or a magnetospeed your best option is to shoot at range say 100y an 200y then use drop to calculate your velocity.

Yeah your not wrong, Optical chronos can be a pain in the ass.

Calculating velocity from shot drops can work but its not a very accurate way of doing things imo. Alot of variables & not only that, need to shoot at some serious distance to try filter out the noise. 200y just isnt enough distance to give you an accurate idea of velocity. Difference in drop with the 150gn Sierra at 2600fps vs 3000fps is less than 3/4 of a minute at 200y. Most peoples cant shoot a 3/4 minute group, let alone have a rifle capable of doing so consistently.