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Hi, kciH:
The Powley Computer treats an increase in case size as linear. So suppose a factory Whelen with a bullet seated has a water capacity of 60 grains and the improved holds 66 or 10% more. You'd expect that 10% more powder should work. The Powley ratio is .86, water to powder, WITH DUPONT MANUFACTURED IMR ONLY. Recent Expro manufactured IMR powder is a bit faster, so 66 X .86 = 57.8 grains of 4064 is a hot load. You'll have to work out your own case capacity and work up.
Since the improved Whelen isn't that much larger than the factory version, dclark's starting point is a good one.
Bye
Jack
The Powley Computer treats an increase in case size as linear. So suppose a factory Whelen with a bullet seated has a water capacity of 60 grains and the improved holds 66 or 10% more. You'd expect that 10% more powder should work. The Powley ratio is .86, water to powder, WITH DUPONT MANUFACTURED IMR ONLY. Recent Expro manufactured IMR powder is a bit faster, so 66 X .86 = 57.8 grains of 4064 is a hot load. You'll have to work out your own case capacity and work up.
Since the improved Whelen isn't that much larger than the factory version, dclark's starting point is a good one.
Bye
Jack
