Originally Posted by
bronko22000
Please explain this. I've been loading for over 55 years now and I'm not sure what this means.
I normally selected a powder that would fill the case to the bottom of the neck with the max charge and give me the highest velocity. This would allow me a wider range from starting load to max load to work with. I always liked using as much case capacity as possible.
A lot of powders will offer a high fill ratio at maximum charge weight - or rather, achieve the cartridge max pressure standard at a high fill ratio. But not all powders will remain reliable and consistent across varying environmental conditions. For example, H335 is great in 223rem, but is exceptionally sensitive to temperature, so what load I develop in an indoor range may end up spiking in the heat of summer, and push me out of a node. Alternatively, Varget is exceptionally temperature insensitive. So any time I can align cartridge case capacity with Varget, 8208, Retumbo, or H4350, I use those over some other powders. For example, Leverevolution is very temp stable, as is Superperformance, so even though LR gives higher velocity in 243LBC and 6 ARC than 8208, I choose 8208 instead because it is more reliable, making it more predictable, and easier to load to shoot smaller than LR. 4064 is less sensitive than W748, so 4064 gets the nod for my 30-06.
Equally, some powders tend to offer wide nodes - great forgiveness - so choosing H4350 makes more sense and shoots smaller for me than RL17.
Eliminating, or reducing sensitivities decreases variability, and decreasing variability inherently increases consistency, and subsequently precision.