I chronoed some rounds through that Wilkinson today and got an average of 608fps for 5 shots from the right barrel, for 369 ft-lb of energy. That is with 70gns of Goex Fg under a 450 grain bullet, and from a 7" barrel.

The left barrel has a much much lighter trigger pull and I was able to get groups of 1.25" at 15 yards. The right was much larger, and also printed much higher and to the right than the left barrel.

The gun weighs 2lb 9 ounces and has 7" barrels. I'm going to try FFg out of curiosity, but think I'll stick to these loads for normal use to minimize wear. I'm also having a slightly larger mold made up (.592" and 500 grains w/solid nose) with a hollow point pin so I can vary the weight a bit. I doubt it will make much difference for a gun designed to shoot things at arms length, but worth a try.

I'll post the results here as I figure out more about this interesting piece of history.