Shotshell Pressure Question?

Roundsworth · 09-20-2010, 11:10 AM

I have quite a few catalogs from WRA Co., Eley and Kynoch. They date from 1881 to 1928. No pressures are given in any of them. I wonder how they came up with velocities. It would be interesting to see what was used as a 'chronograph' 100+ years ago. Testing pressure was probably done with lead or copper slugs in a special chamber. Even so, where did they come up with the standards. In other words, .xxx" squish equates to x,xxx LUP or CUP. Mike and Calvin, I agree with you. I don't handload shotshells (yet), but use Polywads in my non-fluid steel barrels. It does not take but 4 or 5 pounds of energy per pellet for taking a Ruffed Grouse. Cheers!

Drew Hause · 09-20-2010, 01:01 PM

Mike: Tom Armbrust tried to pressure test some vintage loads a few years ago. The results (probably more primer deterioration than powder) were so inconsistent as to be meaningless. He did find a trend toward increased pressure, felt to be from hardening of the old fiber wads and paper cases.

In a 1927 Western Cartridge Co. flyer "Super-X The Long Range Load" by Capt. Chas. Askins, the 12 gauge duck load is described as 38 1/2 grains or 3 1/2 dram with a muzzle velocity of 1400 fps (modern numbers are measured 3 feet from the muzzle) and a breech pressure of 3 3/4 tons or just below the current SAAMI 12g maximum of 11,500 psi.

Austin W Hogan · 09-20-2010, 07:23 PM

Speeds were measured with what is known as a ballistic pendulum. The shot was fired into a bullet trap on the bottom of a pendulum. The speed was deduced from the amount the pendulum rose.
I wish I had my old freshman physics textbook; it had a picture of a ballistic pendulum, and the math outline. It was a really good excercise to convert the potential energy of the pendulum back the the kinetic energy of the projectile, and then the speed of the projectile.

Best, Austin

Mike Stahle · 09-20-2010, 08:00 PM

Thanks Austin,

Very cool info. I learned something today

Autumn Daze · 09-20-2010, 08:47 PM

Check this out....guy's

http://www.google.com/url?sa=t&sourc...p5BgO6SGhyH_mA

Mike Stahle · 09-22-2010, 07:21 PM

Quote:

Originally Posted by Dave Suponski

Check this out....guy's

http://www.google.com/url?sa=t&sourc...p5BgO6SGhyH_mA

Thanks Dave, very interesting

Mike Stahle · 09-22-2010, 07:54 PM

This will be my next pressure test load. This will be my tree-rat load if my baby and I survive.

BTW: I never did hear back from Federal, so much for the "we will reply within two to three days"