01 November 2013, 05:39
Paul ReedExterior Ballistics circa 1936
Greetings AR Colleagues,
Recently a friend of mine inherited some interesting shooting related memorabilia from another friends estate. He was not interested in the stuff and gave it to. After reviewing the material I thought some of you might be interested in one item in particular...but more importantly to show you how far we have come in determining ballistic calculations.
Attached are photos of a set of charts, titled Exterior Ballistic Charts, that were published by DuPont in 1936 and sold to handloaders and shooters. I don't know how much it sold for and the condition of the charts is pretty good considering its 77 year age. Essentially the charts describe how to compute using formulas or graphs various ballistic parameters such as Ballistic Coefficient, Remaining Velocity etc that you can see in the photos below and are self explanatory. The 10 charts and instructions are quite interesting to study and give some insight in the field of practical ballistics in the past.
I ran through the charts using a standard 30-06 load with a 180 Hornady bullet at 2800 fps and it took me about 45 minutes to complete the session and generate all the parameter and measurements! As you will see when you study the charts some of the numbers generate as estimates against a line graph so precision was not anywhere what we have today. In contrast as you know running the load information thorough one of the modern computer programs takes less than 30 seconds.
He also gave me a pristine copy of the Powley Computer and PSI Calculator sold by The Hutton Rifle Ranch. I actually had my on copy of Powley that I purchased about 30 years ago and has some solid wear. It is still applicable today and I will probably use from time to time but of course QuickLoad is faster and more comprehensive.
For those of you who are dyed in the wool inveterate handloaders and ballisticians I post for your interest and pleasure.
Thanks
Paul
Envelope
Front page of the instructions
Published in 1936
I guess the title "Short Cut" was appropriate in 1936
Note that the cartridge list includes three modern "speed demons" like the 250-3000, 270 Winchester and 30-06!
Powley computer
01 November 2013, 21:44
Ole Miss GuyThank you for sharing this bit of history.
I also have all of the above and this was the cutting edge for us back then to learn about ballistics. I would spend hours reading and checking those charts so I would know with great certainty where each of my bullets would land before the trigger was pulled.
Great memories!
02 November 2013, 18:28
SR4759The Powley slide rule load computer is a fairly valuable item these days. I know you might just consider it memorabilia but it might bring $100 or more on ebay. That will advance you loading and shooting budget a good bit.