I am looking for someone (hopefully in Northwest Indiana area) to install a weaver/ picatinny rail on a HR 999 top break revolver so I can switch a scope between it and a Ruger Charger
Sorry I did not include measurements to show what I "hoped" could be done
I have a 2-7 x 32 pistol scope on my Ruger 22 Charger pistol
I mounted a 4.5" rail on the Charger that already had mounting holes
The scope mounts attach to the rail 3" apart
The HR999 appears to have space for a 3.5' rail that would be attached @ .75" & 2" and extend over the barrel
( plus locktite between Rail & top of gun? ... as I will not use the Open Sights )
The frame over the Cylinder is ~.25" thick -- (could be tapped all the way thru and use .25" screws ? )
Last pic is a side by side ... doesnt look pretty - but as long as I can see through the scope --- I am Good
Hope the extra details make it a Not so Impossible task
Your third pic should show you the reason. The transition between the two surfaces will be the problem. Not to mention, the rail bottom will have to match the contour of the top of the weapon.
Again, my advice, don't do it. It will never be right or exact. Not to mention, I highly doubt it will/would ever hold a zero.