From the mental ramblings of Jeff Brown, New Zealand.
In recent weeks I have had cause to catch up with an old shooting friend of mine. 'Gus' (not his real name) is one of life's good guys. Quiet spoken, considered in his thoughts, witty, a wealth of shooting knowledge and above all else and certifiable gun crank and cast bullet shooter. Sadly, due to a relocation and poor health 'Gus' has had to throw in the towel on shooting and was having a clear out of all things gun related. He offered me first dibs on this stuff and I was fortunate enough to re-home a decent amount of powder, primers, shotshell components (what are these shotshells I hear y'all ask) and various other handloading bits and pieces.
Rummaging through his storage facility 'Gus' turned to me and said "these might be of use to you for your .32-20" pointing at a plastic bottle of Lyman 311316 pattern bullets; the little gas check humdinger projectile designed for stouter loads in the .32WCF and assorted other rounds suitable. Grinning back at him I said "I would think they might; that's my handwriting on the the bottle. I gave them to YOU for your .32-20!" That gave us both a good chuckle and the bullets returned to whence they have originated.
A brief study of the label I had affixed to the bottle shortly after they were cast reminded me I had created them in 2008 from clip on wheel weigh alloy 'sweetened' with approximately 2% tin (most likely the tin based babbitt I have) then heat treated by bringing them up to temperature in the mini oven I now use for powder coating and then quenching in cold water. Hardness was recorded in my handwriting of 27 BHN, nothing to sneezed at and for the most part entirely unnecessary.
I have read that heat treated lead based alloys age soften over time. That is to say that with the passage of time the hardened alloy gradually loses it's artificially inflated BHN rating and eventually returns to its natural state. This got me to pondering. Over 13 years had the bullets originally clocked at 27 BHN succumbed to any affects of softening and is so how much? I expected the worst to be honest as 13 years is rather long time and how many of us actually cast bullets and have them around for that long?
Taking a random bullet from the bottle and fastening in the vice a coarse file took enough material from on side to create a flat spot. Into the Lee hardness tester (the same tester the original reading was done with) the bullet went and endured 30 seconds of ball pressure as prescribed by the good folk at Lee Precision. Lining up the calibrated magnifier such that the etched scale straddled the indentation I read 0.05 exactly (measured twice at 90 degrees) translating to 20.9 BHN on the conversion chart that accompanies the tester. That's a difference of 6.1 BHN over 13 years; basically 0.5 a Brinnell point per year. I was staggered. If I was a betting man, which I am not due to Scottish heritage, I would have guessed 13-14 BHN. At 20.9 BHN the bullets are still harder than good quality linotype so more than hard enough for pretty much any application and mostly too hard for many.
So there we have it. I catch up with an old friend, a new lease of life for some retired shooting kit and a new piece of knowledge all in one hit. Ain't life grand?
In recent weeks I have had cause to catch up with an old shooting friend of mine. 'Gus' (not his real name) is one of life's good guys. Quiet spoken, considered in his thoughts, witty, a wealth of shooting knowledge and above all else and certifiable gun crank and cast bullet shooter. Sadly, due to a relocation and poor health 'Gus' has had to throw in the towel on shooting and was having a clear out of all things gun related. He offered me first dibs on this stuff and I was fortunate enough to re-home a decent amount of powder, primers, shotshell components (what are these shotshells I hear y'all ask) and various other handloading bits and pieces.
Rummaging through his storage facility 'Gus' turned to me and said "these might be of use to you for your .32-20" pointing at a plastic bottle of Lyman 311316 pattern bullets; the little gas check humdinger projectile designed for stouter loads in the .32WCF and assorted other rounds suitable. Grinning back at him I said "I would think they might; that's my handwriting on the the bottle. I gave them to YOU for your .32-20!" That gave us both a good chuckle and the bullets returned to whence they have originated.
A brief study of the label I had affixed to the bottle shortly after they were cast reminded me I had created them in 2008 from clip on wheel weigh alloy 'sweetened' with approximately 2% tin (most likely the tin based babbitt I have) then heat treated by bringing them up to temperature in the mini oven I now use for powder coating and then quenching in cold water. Hardness was recorded in my handwriting of 27 BHN, nothing to sneezed at and for the most part entirely unnecessary.
I have read that heat treated lead based alloys age soften over time. That is to say that with the passage of time the hardened alloy gradually loses it's artificially inflated BHN rating and eventually returns to its natural state. This got me to pondering. Over 13 years had the bullets originally clocked at 27 BHN succumbed to any affects of softening and is so how much? I expected the worst to be honest as 13 years is rather long time and how many of us actually cast bullets and have them around for that long?
Taking a random bullet from the bottle and fastening in the vice a coarse file took enough material from on side to create a flat spot. Into the Lee hardness tester (the same tester the original reading was done with) the bullet went and endured 30 seconds of ball pressure as prescribed by the good folk at Lee Precision. Lining up the calibrated magnifier such that the etched scale straddled the indentation I read 0.05 exactly (measured twice at 90 degrees) translating to 20.9 BHN on the conversion chart that accompanies the tester. That's a difference of 6.1 BHN over 13 years; basically 0.5 a Brinnell point per year. I was staggered. If I was a betting man, which I am not due to Scottish heritage, I would have guessed 13-14 BHN. At 20.9 BHN the bullets are still harder than good quality linotype so more than hard enough for pretty much any application and mostly too hard for many.
So there we have it. I catch up with an old friend, a new lease of life for some retired shooting kit and a new piece of knowledge all in one hit. Ain't life grand?