Black Powder Pressures

[Oyeboten]

Does anyone know of any published charts which illustrate Black Powder 'PSI' Pressures in various Loadings, Projectile weights, Barrel Lengths, and so on?


Does Black Powder cease to burn, or top-out, once a certain pressure is reached?



Phil
LasVegas

 

[zimmerstutzen]

Get the first edition of the Lyman Blackpowder Handbook. It is loaded with the charts you request.

Black powder doesn't max out with pressure, it can max out as theball travels down the bore. It is possible with some loads that the powder is not fully consumed before the ball leaves the muzzle and the excess burns as a muzzleflash.

 

[Jim Watson]

Accurate Arms bases some of their smokeless data on what black powder did in an obsolete cartridge. They go up to 21,900 psi in .40-65 based on what they got with 65 grains of FFg and a 300 grain cast bullet.
They say .50-70 reached 22,500 psi with 65 gr FFg and a 550 grain bullet.

 

[Oyeboten]

Thanks everyone..!


Will do zimmerstutzen - I'll find a copy..!


I'm curious to know how high BP pressures can get under normal interior Ballistics situations, as well as what they are normally undersood to be for various Calibres and Bullets.



Phil
Lv

 

[zimmerstutzen]

As I recall, most loads for traditional style guns with moderate loads run around 10 to 12 thousand CUP.(Copper Units of Pressure) Highs are up around 20 thou. However, with new modern steels and in-lines it may easily be 1.5 to 2 times that.

CUPs as a pressure measurement was somewhat variable and suspect depending on methodology and a new measurement unit is often used.

There are guys who are always pushing the envelope in the name of "magnum" performance. I prefer my face the way it is, without the aid of a plastic surgeon. I saw a fellow at the range jamming four 50 grain pellets in a cheap in-line. The crack was excessive and the guy couldn't hit the dirt behind the target stand. worse, he kept blaming the powder charge as too light. I left, figured it was safer and if his gun blew, I'd rather not be cleaning up the mess.

Here in PA where shots are seldom over 75 yards there is simply no reason to use elephant loads.

 

[Oyeboten]

Ohhhhhhhhhhh...believe me, I'm not looking for 'Hot' loads...only wanting to understand BP better.

I'm especially interesed in eventually understanding the original Black Powder .38 Special loadings as thoroughly as possible...as well as the original .45 LC.


I'm interested to know the supposed pressures for Cap and Ball, also.


So...no worries..!

All's well..!


Phil
LasVegas