I chronoed my czechmate last monday I found that I was shooting 178,8pf.
brought the load down from 8,4grs to 8,2grs 3n38.
Shot the open nationals this weekend and was chronoed at 173,4. So the reduction is powder didn't have a very significant effect.
Strange thing is that a buddy of mine have been loading 9 major for 3 other guys shooting czechmates that was bought at almost the same time as mine. same load, same Frontier 124grs bullet, same primers. But 8.0grs 3n38. Those three guns where chronoed between 160,003 and 163.
The guy who chronoed 160,003 is probably the luckiest open shooter I have heard of.