At a COL of 2.80" a Hornady 139g SP sticks over .250" below the neck and into the powder space of the 7mm WSM case. I'm going to be shooting the round in a single shot Savage target action with a throated chamber that will avoid the need to seat below the case neck. The barrel length is 24". Any idea how much performance might be gained? How much more powder to use? Thank you.

Jon

You will just have to work up to a maximum slowly. In a single shot why limit yourself to the 139 SP with it's low BC?