I appreciate your response and will calculate using the formula.
As per the chronograph can you recommend one?
I've got personal experience with Chrony and Pact. They were both priced less back when chronographs were affordable for the first time. A buddy shot my Chrony and that wipes 'em out. I was about to buy another (with my buddy's money) one when I noticed the Pact used wires to keep the machine out of the line of fire. It turns out the Pact has another feature that is even more significant. It's sensors are the farthest apart and that makes it a touch more accurate and a bit easier to align for accurate readings.
I've used the least expensive Pact for over 20 years now. I had a chance to compare it with a "professional" brand once and it read the same. That professional set happens to be the only other chronograph I've ever seen at the range(s) in 20 years, btw.
A lot of the higher priced ones, and deluxe versions have printers and do heavy duty computations. They also offer data bases and such. Truth is, average velocity, max variation, standard and average deviation is about 100% of the really useful info and every one of them tell that without delay. Having a printout would be nice, but a couple that have printers look like their printout formats don't include all 4 of the above.
It's amazing how valuable they are to working out loads. I recently bought a 223 that shoots every powder I've tried in it at least 100fps faster than the factory recipes predict. Some are even more. I've never run into any gun like that before. Thanks to the chronograph info, I know it's faster, and no other before was faster. So thanks to the chronograph info, I load one powder 2 grains below factory max and know I'm getting about 50fps higher velocity. If I threw in that 2 grains, the velocities would be borderline 22-250. And possibly over max pressures.
Without the chronograph, I wouldn't have been able to "wildcat" a 1000yard target 22-250. VLDs had just started showing up and it dawned on me that a quick twist barrel on a 22-250 might work for the long range matches that were just then seeing the serious magnums. Chronograph info is way more valuable than most people imagine. At least for honestly serious results.