Mike,
Thanks for the nice comments. No, this is the second one I built, the other one is already in Florida. This one is currently residing in Canada on a bear hunt. I delivered it last week to the owner who was coming through on his way up there to hunt with a friend. As far as targets go, I don't think I have any left but I'll look. It seemed to be very hard for me to shoot really small pairs with it because I was shooting it over a standing rest. It is even a bit hard to tell when you've got it where you want it because of the weight of the gun and the fact that the rear trigger was set substantially harder than the front trigger.
I remember that I shot one right / left pair at 25 yards that I could lay my hand on and the pointer and middle fingers rested naturally on the two holes. That would have made them about 1 1/4 inches apart center to center. The guy who owns this was only wanting it close enough to hunt with and I certainly got him that and more. The center to center measurement at the muzzles would have been about the same 1 1/4 inches apart, that would make it shooting pretty much parallel.
The gun actually weighed 12 pounds 9.6 ounces empty, and even at that the recoil was brisk to say the least. The first time I fired one of these I had a friend with me as an observer. He is a big guy, 6'4" and about 260 pounds. I have a bad leg so I asked him to stand behind me about a step and a half an catch me if I started to go over backwards. I leaned into the gun and touched off the first shot and I did have to take a partial step backward to keep from going over.
When I got done firing both barrels I asked him if he wanted to try it. With wide eyes he told me that he didn't think so, and he implied that I was crazy for shooting it myself. The recoil from these very large bored guns is different than magnum recoil, it is more of a heavy shove, and it is something that anyone can learn to deal with. I have offered several friends chances to fire one of these and they almost all refused. The only guy who would shoot it was a smaller framed guy who was ex military, he shot it with no problems at all and declared it a BLAST! He probably doesn't weigh over 170 pound or so and is almost a head shorter than I am. Bob