I promised I'd comment on the pro's and con's of this sight once I'd given it a go. I have had to wait until my right shoulder healed up enough to take the recoil of my "Squib" loads, but now I've shot it twice for a total of about 85 rounds, and don't feel any the worse for it.
As you may recall, my front sight was very close to the muzzle (oops) and high off the barrel. Using the centre of the "aperture" for a centre hold on my target at 50 yds. I ended up filing that front sight down to about 1/8" off the barrel. I stopp0ed when I got to this stage, rather than filing it down to use the nick at the bottom of the opening though I might do so in the future some time. So, with 90 grains FFg GOEX, .020" spit lubed ticking patch, I was able to keep all my shots in the black, whether off the bench or off-hand. It was a good start, and I know more testing is in order.
On Sunday, I shot our trail, and found the sight very easy to use at targets 10 to 110 yards. I was able to cut two intersecting lines and cut a playing card at close range, and ring targets that were out there too. I like the sight - it's amazing how your eye will centre it without effort.