S&W 645 Mod 3 Gas Ring

[FrankObrad]

I have a S&W 625 Mod-3. I was going to replace my SS cylinder with a titanium cylinder. I purchased Titanium Cylinder (PN 294980000) from S&W parts. The Titanium cylinder did not come fitted with a gas ring. And my SS cylinder's gas ring has seized into the cylinder. Or it was never supposed to be removed. Where can I buy a SS gas ring for a 625 Titanium Cylinder. I have sent several messages to S&W with no reply. I have contacted a dozen aftermarket parts sources and no one has them. I bought an extractor collar from MidwayUSA that everyone has told me is the same as a gas ring and it wasn't close to fitting.