Muzzle velocity question

[Bigbubba]

So if a person does not have a chronograph....

And they try out a bunch of different loads to find the best one for accuracy....

How can they then figure out MV ? of said load?

I know the bullet weight and BC and powder weight etc

Is there a calculator out there?

thanking you in advance........

 

[IvoB]

Most loading manuals would give you barrel length usually 24 inches subtract 80-90 feet per inch would give you a ballpark figure.

 

[vagrantviking]

Sight in at a known distance and see what the drops are at other distances. Then find a calculator. I'm sure someone can recommend one or 2.

Can be quite accurate from what I've heard but not done it myself.

 

[Alpheus]

Two options.
1) find someone with QuickLoad who is willing to run the numbers for you.
2) find a ballistic calc that has a velocity calibration feature, which lets you put in various drops at different distances and outputs a best guess of the muzzle velocity.

 

[todbartell]

 

[Ganderite]

So if a person does not have a chronograph....

And they try out a bunch of different loads to find the best one for accuracy....

How can they then figure out MV ? of said load?

I know the bullet weight and BC and powder weight etc

Is there a calculator out there?

thanking you in advance........

Do you celebrate Christmas at your house? Ask Santa for a Chrony.

Celebrate your birthday? Treat yourself to a Chrony.

You will have a lot of fun with it, learn a lot, and make better ammo, too.

 

[B]

^ you can buy a very decent kit for under $200 these days. I have somewhat of an addiction to chronographing my shots. There is no such thing as too much data IMO...

 

[Potashminer]

If you want to go very "old school" and possibly cross-eyed ciphering the associated numbers, look up what is a ballistic pendulum and how to work it. Basically a weight that will catch and stop a bullet (like a big old section of stump), on a very precisely measured set of pendulum legs, with very detailed measurement of the distance of pendulum action and timing of the resulting oscillation, along with the weight of the stump and the weight of the projectile that it caught. Nit pickers apparently also factored in the resistance of the pendulum leg's bearing points. I think it was the only way to get a somewhat true velocity number, until 40 or 50 years ago... Hence, much easier to spend $150 on a gizmo today - much less "ciphering" involved to get a velocity number...

 

[Cameron SS]

So if a person does not have a chronograph....

And they try out a bunch of different loads to find the best one for accuracy....

How can they then figure out MV ? of said load?

I know the bullet weight and BC and powder weight etc

Is there a calculator out there?

thanking you in advance........

How accurate do you need to be?

If you don't need to be that accurate, then you can probably guestimate simply by bullet weight, cartridge, barrel length and charge weight. With those four points people here should be able to estimate you to within 50-100 FPS.

If you need to be accurate, you need a chronograph.

You can reverse engineer your trajectory by firing at various distances without correcting for elevation and measuring your drops, but in order to be very accurate you would need to benchvice the gun and have precise measurement tools that probably cost more than a cheap chrony.