I was always a tinkerer, probably why I never won more often.

To the point, have any of you ever bothered to load test with bullets of varying cast dates?  CBA  top shooters told me they made it a point to cast about three to four weeks before a match for max Bhn.  Three months old would soften slightly.  Six months old a bit more.  Like 1Bhn each date.  The theory was bullets of varying age/hardness would shoot to slightly different POI.

just curious,

Rich

I believe you are correct that most of us would like two cast with two part alloys but we also use lots of reclaimed with the third element antimony ( hopefully no Zn )  therefore ternary ? I’ve read of lead bullets aging and getting harder or softer can’t recall which. Verbal Smith of LBT Technology talks about this in some of his papers and I respect his opinions and advice re: lead bullets

burntwater wrote on Sep 1^st, 2021 at 9:11am:


I like to avoid antimony if possible.   Scrap sheet lead and pipe don't contain much, if any.   I have observed  a sort of filmy deposit in the barrel with antimonial alloys, sort of like chalk dust on a black-board.  Easily removed with a little abrasive or brushing.   And antimony  DOES lead to unpredictable hardness variations with time and temperature.

I don't feel like a LOT of hardness is needed for black-powder target shooting applications, tho the trend in that area is toward harder bullets.  Next time out, I'm going to test some 15:1 alloy and compare to 20:1.   This is not a BIG change.  PLumber's lead is ~ 5 BHN, 20:1 ~ 8 BHN, and 15:1 ~ 9.3

With the addition of antimony and a little arsenic, I have achieved heat-treated hardness of 30+ BHN in some 25 caliber bullets, but they didn't shoot well.

CHRIS

What I find interesting is Linotype works extremely well in the CBA Production and the Heavy Classes. But I have never been able to make it work with any type of success in the Plainbase Class. One would tend to think that the only difference being the use of Gas Checks would not actually make that much of a difference. Especially so at the much lower velocity ranges that we typically use. I believe bullet hardness is indeed a big plus. To minimize nose slump and other unwanted variables as the bullet changes its original form while going down the barrel. 

Lead:antimony alloys which have traces of arsenic (0.5% TO 1.0%) will harden over 90 days after casting whereas lead:tin alloys will soften over 90 days after casting.
I always cast my bullets in the winter and their hardness had stabilized when I shot them in the summer.

Antimony & arsenic:lead alloys can increase their hardness (quickly) by heat treating.

Handloaders' Bullet Making Annual - January 1990: "Alloys" and "Heat Treating Cast Bulllets" by Dave Scovill; Wolfe Publishing Company ISSN 0017-7393

'...cast my bullets in the winter.... stabilized... in summer'
Well that sure would explain why the ones from the 1950s that I have seem to remain uniform.