I will give this a try.

by John K., Monday, March 25, 2013, 17:35 (4264 days ago) @ Dave B

Low SDs are a good indicator of a good process. Another proof of this is saving a few of the first "good" bullets from a mould, just as you think it is up to temp - not wrinkled, but the bullets are quite shiny. Weigh them and compare to bullets cast later. Likely will group outside of your normal distribution. I found I had two "bumps" on my bell curve and it was related to stopping and adding sprues back to the mix - both the melt and the mould were cooling down ever so slightly. Each group of bullets shot well if kept seperated, but again I did not want to inspect quality into my product.

Of course, we are getting off on a tangent, but IMHO these things help with long range cast bullet shooting.

And just because I like posting pics:

That's ten shots @ 100yds, Swiss black powder under 535gr 457132 Postels. Indescribable fun to beat up the 1123yd buffalo at Raton with that rifle and load. Shoot.... wait 3.5s for the bullet to get there... spotter sees hit with spotting scope, calls hit.... 3.5s later the "bonngggg" floats back....