How was muzzle velocity determined way back?

[Ironworker]

How did they measure muzzle velocity way back in WW1 and WW2

 

[Herzo]

Stopwatch???

 

[Rocketvapor]

Old fashioned methods;
Impact momentum, with a pendulum and known bullet mass.
Rotating drum.
Strobe lights and camera.
Electrical break sheets and timer/counter.

Ballistics - Clocking Bullet Speed - Guns and Ammo

William L. Casteel wrote 'How fast do she go? and How do you know? ' in the October 1970 issue of G&A. Casteel examined how bullet ballistics are measured.

www.gunsandammo.com

 

[Murray Brook]

I'm guessing Trajectory

 

[JoeDuke]

They used a ballistic pendulum and a slide rule. In freshman college physics, we built one and fired a .22lr into it; right in the classroom. Google it

 

[Rocketvapor]

NASA used impact pendulum to test Graphite/Epoxy composites for use on space stuff.

Various layups were tested on 4" X 4" panels at velocities up around 6000fps with 1 gram projectiles.
I joked I could blow though one with my .357. "No Way" was the response.
Took a 12 layer 4mm thick piece spray glued to a piece of 1/4" plywood, went to my test range (dump) and fired a 70 grain FMJ .356 bullet through it with my 8" DW.
When I brought it back they X-Rayed for internal damage and found radial streaks of copper between layers with delaminations about 2" in diameter. Their 1 gram projectile left a fairly clean hole.
They took some of my reloads to Huntsville and clocked them at 3100fps.

 

[c3d4b2]

Ballistic Pendulum

 

[rlporter507]

there was an early chronograph that had a 2 metal screens and a pretty complicated box it was wired to with a chart to come up with the speed. you had to replace the screen or patch it after use.

 

[Tommie]

Dont recall if it’s Volume 1 or Volume 2 but there’s a diagram of a ballistic pendulum in Adkley’s book

 

[243winxb]

early chronograph that had a 2 metal screens

Card board with a copper wire weaved into it. Took 2 for each shot, is what i first seen in the 60s. They let me fire my gun thru it.

 

[rockhound78]

Earlier Lyman loading book has a pic of a ballistic pendulum.

 

[Laurie]

MVs have been calculated since early black-powder metallic cartridge days near 150 years ago - when there were no electronics and people did basic physics the hard way. As several posts say, a ballistic pendulum was used. Shoot at it and measure its movement. Knowing the bullet weight, the pendulum weight, and the amount of movement, you can easily calculate bullet energy and from that its velocity.

 

[dellet]

Stopwatch???

Basically.
A shaft with discs spaced at a known distance, rotating a known speed.

Bullets fired through the discs, speed calculated by distance traveled and amount of rotation, time.

Pretty sure that’s where the “chronograph’ name originated. Clock/watch technology

 

[Rocketvapor]

Do your own experimenting.
Small samples of piezoelectric film, connected to a storage scope. Set up a known distance, shoot, measure time between blips.

One advantage of the pendulum method is absorbed energy can be calculated for a through and through as well as a stopped bullet.

 

[wboggs]

Stopwatch???

In the 60s I had a ? Pacific with start and stop screens and an aray of led lights connected to an oscillator tube. You would look at the lights and calculate velocity. It seemed to be pretty accurate. I would shoot factory ammo as a control and then my handloads. Should have kept it for historical value.