Ruger Super Blackhawk cylinder gas ring clearance - UPDATE

[SSL]

I picked up a replacement cylinder for my Super Blackhawk .44 Mag (going from non-fluted Dragoon Style to fluted style). It drops into the revolver and aligns all chambers to the bore perfectly, but seems a bit off regarding the gas ring to frame fit. With the cylinder held to the rear, the B/C gap is .005" and the gas ring/frame gap is .018". Pushing the cylinder forward, the B/C gap is .000" (actually contacts the barrel) while the gas ring/frame clearance is .013". I know I can always always use cylinder shims to maintain the proper gap of the barrel to the cylinder (maybe .003 - .004"), but are there other issues? I've worked on Ruger single actions for years without ever encountering this particular issue. Any ideas from any gunsmiths here or am I on the right track?

 

[jackieschmidt]

Doesn’t the gas ring also act as the forward thrust on the Ruger, maintaining the proper barrel to cylinder gap? It is not like a Smith & Wesson that mounts on a crane, using the inside face of the crane to maintain forward thrust.

So, it seems to me that the gas ring sticking out of the cylinder front is too short. It would appear you need about an .018 shim in front of the gas ring.

measure the length of the gas ring on the non fluted cylinder and compare it to the new.

 

[SSL]

Doesn’t the gas ring also act as the forward thrust on the Ruger, maintaining the proper barrel to cylinder gap? It is not like a Smith & Wesson that mounts on a crane, using the inside face of the crane to maintain forward thrust.

So, it seems to me that the gas ring sticking out of the cylinder front is too short. It would appear you need about an .018 shim in front of the gas ring.

measure the length of the gas ring on the non fluted cylinder and compare it to the new.

Thanks....shim to 018" is the figure I came up with too. I just wanted another mind working on this. My math skills deteriorated after I had a finger amputated! (At least that's my excuse.)

 

[Alan Warner]

Take your shoes and sox off

Thanks....shim to 018" is the figure I came up with too. I just wanted another mind working on this. My math skills deteriorated after I had a finger amputated! (At least that's my excuse.)

 

[SSL]

Got my shims today and all is well. Ended up with a nice consistent .004" BC gap and virtually no perceptible end shake.
If you are looking for firearm shims of darned near any type, I would strongly suggest https://triggershims.com/
Lance is fast, caring and dependable. He even sent a couple extra at no charge to give me a wider choice of combinations to get things just right. Such conscientious service is fairly rare these days!