Here's the Valtro updates (sans mag)... Took some machining to get the Mesa Tactical LEO stock adapter on, but now I have adjustable LOP using AR stocks. I also opted to go with the Umbrella Corp P23 grip (now made by B5 products) as it is more vertical and helped with the angle of the pistol grip vs. the stock.
The Holosun 403C has stood up to 400 slugs and target loads without losing zero, so it's looking like a winner too.
I ran this at the Tactical Shotgun match earlier this month and took third in Open class. Pretty happy as it was my first match and only second time running the Valtro. I suspect things will improve as my manipulation of it smooths out. I can tell you I was getting envious glares from the handful of guys wrestling with their frequently malfunctioning box-fed shotguns from other manufacturers...
Anyone know ANYTHING about the externally threaded chokes this originally shipped with? I tried the external choke from mi amigos FABARM, it was close but didn't *quite* fit. I'll clean up with this thing if I can get chokes to tighten my shot patterns up at distance... Cylinder Bore at 13.5 inches isn't much for patterning at 25m!!!