I don't know about the Alliant loads but with Speer's 6.5 Grendel load data using IMR 8208 with 120 GD their max loads are way low compared to what I found with two different rifles using a chrno.
I don't know about the Alliant loads but with Speer's 6.5 Grendel load data using IMR 8208 with 120 GD their max loads are way low compared to what I found with two different rifles using a chrno.
Noticed that with multiple cartridges on the Speer site when looking at either IMR or Hodgdon's. They are WAY low on velocities for those powders. I suspect Speer's data with the Alliant powders are more in line with actual numbers.
Hodgdon's site seems spot on velocity wise with the IMR and Hodgdon powders. And checks out on the chrono.
I've more than once took Hodgdon's top velocity listed, subtracted the starting velocity listed, divided that number by the number of grains between starting and top load, to give me the average fps increase per grain of that powder. Based on my load I added the increase on top of their starting velocity, and deducted barrel length if needed. When I chrono the load, it's right at what I figured ahead of time.
