I shot a few different loads over the chronograph today.
19.8gr 300-MP, WSPM primer, Lee 358-125-rf coated with VHT epoxy
Avg. 2146fps
Ex. spread 109fps
Shots fired 15
No leading, outside of cases were sooty
20.3gr 300-MP, WSPM primer, Lee 358-125-rf coated with VHT epoxy
Avg 2178
Ex. spread 31
Shots fired 5
No leading, outside of cases were sooty
21.0gr. 300-MP, WSPM primer, Lee 358-125-rf Harbor Freight red
Avg 2264
Ex. spread 39
Shots fired 8
Bad leading in bore,
I will have to investigate that 20.3 grain load a little more. I don't know if the extreme spread is just so tight because I only fired 5 shots over the chrono, well, that the chrono picked up. If I throw out the high and low velocities of the 19.8 grain load I get an extreme spread of 47fps.