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Question:
Cartridge performance is a function of three generic parameters: case capacity, bore size, and bullet weight. Neck angle, case length, and all that other stuff is just fluff for gun writers, add men, and blogs like this to expound on - they have very little real effect, some perhaps, but not much.
The concept of an “ideal powder speed” is a function of those three key parameters listed above and nothing else. The geometry of the cartridge and bullet seating depth come into play, but only in that they impact case capacity.
Link to an online Powley Computer that will do a lot of what Quckload will do, and costs you nothing:
http://kwk.us/powley.html
Sadly, the links to the supporting pages aren’t coming up today. Hopefully, that‘s a temporary issue they‘ll get corrected. There was a lot of good information there. (Update: all the links are working now).
Some of the math is explained on the Internal Ballistics Home Page:
http://www.mindspring.com/~sfaber1/
The scientific study of internal ballistics goes back to at least the 1880’s, when some of the best minds in physics, chemistry, and engineering worked for the military to develop the basic equations that are still used today in the simple thermodynamic models like Quickload, Load-From-A-Disk, and Powley‘s equations.
It’s funny. You can read some of these old text books and published papers that are over 100 years old, and you’d think you were reading from a recent copy of Handloader magazine. The basics haven’t changed. That’s not to say the science has stood still. The models that powder companies, ammo makers, and the military uses now are so advance it’s become nearly incomprehensible to the layman.
Answer: Thermodynamics
Cartridge performance is a function of three generic parameters: case capacity, bore size, and bullet weight. Neck angle, case length, and all that other stuff is just fluff for gun writers, add men, and blogs like this to expound on - they have very little real effect, some perhaps, but not much.
The concept of an “ideal powder speed” is a function of those three key parameters listed above and nothing else. The geometry of the cartridge and bullet seating depth come into play, but only in that they impact case capacity.
Link to an online Powley Computer that will do a lot of what Quckload will do, and costs you nothing:
http://kwk.us/powley.html
Sadly, the links to the supporting pages aren’t coming up today. Hopefully, that‘s a temporary issue they‘ll get corrected. There was a lot of good information there. (Update: all the links are working now).
Some of the math is explained on the Internal Ballistics Home Page:
http://www.mindspring.com/~sfaber1/
The scientific study of internal ballistics goes back to at least the 1880’s, when some of the best minds in physics, chemistry, and engineering worked for the military to develop the basic equations that are still used today in the simple thermodynamic models like Quickload, Load-From-A-Disk, and Powley‘s equations.
It’s funny. You can read some of these old text books and published papers that are over 100 years old, and you’d think you were reading from a recent copy of Handloader magazine. The basics haven’t changed. That’s not to say the science has stood still. The models that powder companies, ammo makers, and the military uses now are so advance it’s become nearly incomprehensible to the layman.
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