Traded a 1960 Willy's jeep for a 7.5 ruger blackhawk. Good gun but had been shot a ton. I know the previous guy, he handloaded but loaded near max and shot the [beeep] out of it.
Was shooting with my dad who was the best natural pistol shot I ever knew and he said the gun was shooting blowbuy. Barrel cylinder gap.
The gun was great, even with the gap, it would shoot.
Got older, could not see anymore and decided to have it scoped. Tried a few different scopes but would never hold center. It was the mounts. Sent it to SSK Industries and they installed their TSOB mount. Never had a problem since. Still shoots great.
As far as the blowbuy. Ruger tightened the gap at no charge. Good gun good company. And if you need a mount that will hold, contact SSK.
This is a Ruger 7.5, I have shot whitetail and black bear with it and 2" on the barrel will not make it perform any better.