Here are a couple of pictures of the Artillery rig in action at the range yesterday. Given that the average 1917 German soldier probably wasn't 6'1" and ~210 lbs, I probably need to take the time to let the strap out a couple of notches as it was a bit of stretch to get it over my head and arm.
As I mentioned in the other thread, it ran through three full magazines without a hitch. That snail drum is looking better and better.