Weighing and lubing the Eras Gone English Kerr revolver bullet
So I got to break out the new Eras Gone Kerr revolver bullet mold and give it a go this week.
I cast the bullets in pure lead. It's a double-cavity mold, so you can crank them out fast.
I made up a batch, and then weighed each bullet, and put them into a spreadsheet. I used to just find the average, and then toss anything that was +/- .5% But I decided to figure out how to do a Normal Distribution of the weights. Turns out that +/- .5% is just about the same as 1 Standard Deviation.
For the Kerr bullet, my bullets had a Standard Deviation of 1.4 grains. So, this gave me a spread of 2.8 grains.
Sorting the graph in ascending order is insightful as you can see the sharp drop off in weights from cold bullets, and the slight up-turn at the high end for hot ones. Most of the time, low-weight bullets have obvious wrinkles. But, most of the time they are bullets I would have kept just by eyeballing them. I suspect the hot bullets are a result of the lead pot level going down, resulting in a hotter melt. I have not verified this, but I do notice as the pot runs down my bullets started to pick up a purplish haze as they cooled off, so I suspect my bullets towards the end of my casting session were dropping hotter than at the start. Or it could just be that the pot was not fully up to temperature when I started casting.
Let me head off the eye-rollers from the get-go. I'm not suggesting anyone has to go to this level of effort to weigh and analyze bullets. As you can see, only a few bullets are outliers. If you start with a hot mold you won't see much variation and so it's probably overkill. I just enjoy trying to eliminate variables in my shooting and I like the analysis of the bullets.
To lubricate them, I dip-lubed them in an old metal musket cap tin on a hot plate. I like to line up the bullets on the hot plate around the tin to pre-heat them, then I set them in the lube, pick them up with needle-nose pliers, and then smear their bottoms on some wax paper to get the excess off the base, and then set them on the wax paper to cool.
I then shoved the end of each bullet into a .45 ACP case, which shears off the excess lube on the "heel" of this bullet.
Steve Sheldon
Commander
4th Louisiana Delta Rifles
NRA Certified Muzzleloading Instructor
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