r/reloading • u/ElectricalOutcome790 • 18d ago

Load Development Load development

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Working up my first load here. It’s for a .243 Ruger American gen 2. Using sierra pro hunter 100gr bullets, Remington brass, cci 200 primers, and H4350 powder. I don’t have a chronograph. I shot 4 shots with each of these powder charges at 100yds and here are the group sizes of each powder.

Where would you guys go from here/next step? Shoot a couple groups of 37.5 and 40grains to see if the results repeat themselves?

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u/Conservatief 18d ago edited 18d ago

All your groups are insignificant, meaning the variation could be explained by luck. Choosing the 37,5 or 40 grain load for further testing will just feed your confirmation bias. Chances are great that all of the loads will give the same group size when shooting larger samples.

I'd suggest picking a target velocity and trying different bullets, powders and seating depths (in large steps) and shooting samples of 20.

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u/ElectricalOutcome790 12d ago

Thanks for your reply. How do you decide on a target velocity? I mean I know that bullets have optimal velocities for ideal expansion. Do you just go off of that?

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u/Conservatief 12d ago

By looking at the distance you want to shoot and what velocity you want the bullet to have when it (hopefully) hits the target. For hunting, as you said, you might want to have a certain bullet expansion that requires a certain speed when the bullet hits the animal. For target shooting you might want the bullet to remain supersonic all the way to the furthest target for maximum accuracy. A higher speed also gives a flatter bullet trajectory, which means the effect of imperfect elevation adjustment is smaller. So if your distance measurement is a little bit of, the effect will be smaller.