Shooters Forum banner
1 - 1 of 7 Posts

· Inactive account
7,804 Posts
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.

1 - 1 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.