Gunpowder Analysis 7mm PRC

[wabash503]

RS Nation,

Need to borrow some brain power from you guys. I've purchased a 7 PRC and I'm researching load development...yes I've already read through the threads here and elsewhere. What I've done is take a look at the recommended powders for 160 gr bullets from a few different major manufacturers, and then took a look a published velocity and charge weight spreads (see table below).

Is it a good assumption that lower velocity spreads per grain of powder should produce lower ES and SDs? Thanks for your help!

Wabash

 

[A382DWDZQ]

From that list, just go with RL26, or IMR8133 if you can’t get RL26.

 

[wabash503]

From that list, just go with RL26, or IMR8133 if you can’t get RL26.

Thanks for the input... Any thoughts on the data?

 

[A382DWDZQ]

I would not make the assumption that the lower velocity spread in the data will work out to a lower ES or SD. When I look at which powders I want to start with, I usually look at what the bullet manufacturer recommend if that is available, then what powders seem to be known to perform well. If that information is not available or powder is not an option, then I look at % fill for the powder and % propellant burned and try and use the highest velocity & lowest pressure that has high percentages in both of those. That yields a few powders to try and that seems to work well for me for getting peak performance for a particular load. I would also say that some of the mistakes I made were not paying more attention to quality control on my loads early on, trying to force a combination that had good looking numbers on paper to shoot well, chasing velocity when I had a great load at starting charge, and wasting too many rounds on ladders.