Am Rifleman Bullet Hardness Testing Method- 1959

[leadman]

I was rereading some of my old American Rifleman magazines recently and came across an article in the January 1959 by C.E. Harrison on a method to test the hardness of a lead alloy. I scanned the article and will post it here along with a handy chart a member sent in for the April 1959 issue.
I haven't had the time yet to test this method but the author is well known for his accurate info. so it should be good.
If others here want to test it and find it valid maybe it could become a sticky? Appears you may have to print the articles so you can read them.
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[runfiverun]

this is the basis for the lee hardness tester.
measuring the indent and converting on a chart.

[leadman]

I thought this would be a low cost method for some members here to test their alloy if it proves worthwhile. The only thing I need is a bearing large enough to use.
I do have a Saeco tester so when my neck heals up from the nerve ablations I'll give it a go.

[runfiverun]

it would mainly because like back then it's easy and repeatable.
the first hardness tester i ever seen was a reloading press with a ball bearing on the ram.
and a weight that hung from the handle.
the guy would put an ingot on top and lower the handle so the weight was between the ram and the ball.
then he would hang the weight on it.
he would time off 20-30 seconds,and then measure the dent to a chart he had made.

[303Guy]

You're giving me ideas - like measuring the movement of the end of the handle rather than the diameter of the indent. That would still have to charted which could be a lot of work but thereafter, it should be a breeze.

[runfiverun]

just so it isn't at the mechanical cam over point it's repeatable.

[Cane_man]

real interesting... but can't read it! anyway to attach it so it can be read? thanks :)

[303Guy]

Yup - the images are too small to read.

[jsizemore]

The article I have by Col. Harrison doesn't use a chart. He says to squeeze the ball bearing between an ingot of known alloy and the one you want to test. Measure the indent of each and divide the known alloy's measurment by the unknown's. Square the result and multiply by the known alloy's BHN. This result is the unknown alloy's BHN.

The example in the article used soft lead with a BHN of 5. The measurment of the ball bearing indent in the known soft lead was .210" and the unknown was .103". Divide .210/.103=2.04.
Square 2.04=4.16. Multiply 5x4.16=20.8. Close to linotype with a slight loss of tin and/or antimony.

No need for a chart.This article was in the NRA Illustrated Reloading Handbook which is a collection of articles from Am Rifleman magazine from 1950-1961. Great book.

[Cane_man]

^^^ awesome, makes sense...

how big of a ball bearing would you use?


edit: looks like Lee uses a 3mm ball...

[jsizemore]

The article said any size will work but 1/2" or larger makes taking a reading easier