prowley computer

[oldbear1950]

I was reading some posts about the prowley computer, did not know there was an on line edition, but took an old correspondence course years ago, north american correspondence course in gunsmithing and it was part of the course, still have all the course materials and the prowley computer, but have not used them in years.
The school was bought out by Penn Foster, and is there gunsmith correspondence course now but without the prowley computer.

[pertnear]

I remember seeing ads for the Prowley Computer but I never had one. I did have a Speer Ballistic Calculator at one time, but it got away from me some how. Wish I still had it. It was made of thick card stock & it worked sort of like a slide-rule. IIRC

[Nueces]

Those interested in an online search will do better spelling it "Powley." Named for it's inventor, Homer Powley.

[oldbear1950]

the prowley computer I works like a slide rule, and in fact it came in 2 different slides. I have not used it in years. But when took the course then started reloading for 45-70, worked great

[Red River Rick]

I have one, still use it occasionally.

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[kaiser]

I still have a Powley computer, and a Speer Ballistic calculator. I seldom use either; however the Powley computer (slide rule) is quite useful when trying to determine starting loads for obsolete, or "wildcat" calibers. It's surprisingly accurate and was available at a time period when sophisticated computers and pressure measuring devices were not as precise or commonly available! Most of the early reloading manuals of the 60's and 70's appeared to be based on a SWAG (better than a WAG!); thus, newer manuals have reduced many of their "Maximum Loads" (some overly so due to legalities)! The Powley (IMO) put workable pressure reloads into perspective with regards to useable and safe loads without stressing the firearm or the user. The powder used in the Powley is dated and limited, but still available and applicable in today's market.
The Speer Ballistic calculator is was more of a "ball park" slide rule for velocities of common calibers when chronographs were too few and too expensive for the average person to purchase. It basically provided velocities for the factory loads according to bullet weight and published velocity by Speer. Trajectory is also provided by this calculator over the typical range of the cartridge listed.

[stubshaft]

Still got mine floating around. I remember poring over it trying to find safe loads for some of the wildcats I cooked up.

[lotech]

I have two Powley computers but haven't seen or used them in a while. Very helpful when I was was trying to work up load data for a .375 Whelen Improved years ago. I may not remember this correctly, but it seems they were only set up for IMR powders. I don't know if they were ever updated for use with other powders.

[Larry Gibson]

I also still have a Powley Computer and a Speer Ballistic Calculator. Also still have a set of Dupont Exterior Ballistic Charts.

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