Several years ago, I called S&W about my then new 296 (2.5" hammerless 5-shot .44 Special with an Al frame and Ti cylinder). I was told that lead was not advised due to bullet creep, but have since learned that lead contaminants on the cylinder face may require more aggressive cleaning, another possible problem. I was also cautioned to keep the cylinder chamber's full - ie, no .44 Russians - again, due to the otherwise need for more aggressive cleaning. Cleaning with Hoppes and a brass/bronze chamber brush is fine - just allow plenty of time for the solvent to work, thus requiring less mechanical (and abrasive) work. I use an M16-style nylon brush and Hoppes on the cylinder bore exits... certainly hide the 'Lead-free' cloths! Also, avoid bulging/split cases - the Ti can be scored or nicked, which can propagate. I quit using the Blazer 200gr GD's in my 296 after one of their brethren split it's Al case in my SS 696... use brass!
Yeah, SS/carbon steel is a far better - and less tempermental - cylinder material.
Stainz