Muzzle velocity without a chrony

old #7 · Oct 25, 2007

I haven't got around to buying a chrony yet, mainly because there are to many guns to buy first. That seems to be a never ending battle that I will probably not win but, I will die trying.
Anyway...
Do you guys know a math formula or how to manipulate a balistics program to show velocity based on bullet path. I am shooting a 7mm bullet, 160gr AB, the path is 2.5" high at 100yds and @ 200 1.0" high.

jtoews80 · Oct 25, 2007

This one is good, but needs a velocity value. So you could guess and then see how close the numbers come to that trajectory.

http://www.biggameinfo.com/BalCalc.aspx

More than likely someone has a better idea, and then I'll use it too :?

old #7 · Oct 25, 2007

MY math teacher in high school would say, " I told you that you would need to know this."

JD338 · Oct 25, 2007

You really should consider getting a chronograph. When you do, you will kick yourself for not getting one sooner!
As jtoews80 said, http://www.biggameinfo.com/BalCalc.aspx is a good one.

JD338

Black-tailed bandit · Oct 26, 2007

i use the pro chrono and love it.

Guest · Oct 26, 2007

I like my PACT Professional, but I won a Beta Master Chrony a couple of years ago, and my PACT hasn't been to the range since that first time I took the BMC.

As an aside, I did a little figuring, and I imagine your load is clocking something like 2800fps, if I am figuring correctly. This is pretty much a wild guess, as I am unable to get the trajectory you're getting (exactly) with the 160AB, and I don't know your load, or I could get much closer.

FOTIS · Oct 26, 2007

YOU NEED A CHRONO!

It is an eye opener dude! Anyway...

http://noslerreloading.com/phpBB2/viewtopic.php?t=2459

enjoy!

Ol` Joe · Oct 26, 2007

If you figure velocity from bullet drop you need to know the exact BC of the bullet, and that figure changes depending on velocity. :shock: The manufactures don`t list the velocity they use to figure their BC so you are working with possibly flawed data to start. Spend the $60-$70 (or more if you feel it`s needed) and get a chrony, you`ll be glad you did in the end.

http://www.midwayusa.com/eproductpage.e ... t=11082005