There are shims called end shake shims. But I think the thinnest is .002. You really should check your end shake before proceeding. Get a set of feeler gauges at any auto parts store and moist hardware stores. They are thin leafs of spring steel and should at least read from .002 up. You are really only interested in .002 to .012. Knowing that your cylinder touches the barrel we know that your forward measurement is 0.000. Now press the cylinder to rear and find the smallest gauge that will just slip between barrel and cylinder .004 to .006 is ideal. I try to shim so I only have .001 end shake. You do not want cylinder to tight on yoke barrel as it need some slack to rotate free.

If the gap between barrel and cylinder is under say .003 with cylinder pressed back against recoil shield as it should be with shims to achieve minimum end shake, you really need the barrel end trimmed to achieve this. There is a tool for this, but it can be done with a file that has had teeth removed on the sides. But, you must know how to run a file. Barrel straight down in padded vice. File held dead flat on barrel end and kept flat and level during every stroke. Stroke only in direction that file cuts, reposition steady stroke, reposition. DO NOT ROCK FILE.

The tool is available from Brownells
cutter- BROWNELLS 90^0 CHAMFER CUTTER | Brownells
basic kit to use with cutter- BROWNELLS 90^0 CHAMFER CUTTER | Brownells

But, the cost of those is more than the cost of a gunsmith,

Also, you could probably send it in to S&W for repair

PS. a bent yoke will NOT cause the cylinder to hit in one spot and not the other. As the cylinder turns on the yoke barrel and as the yoke barrel does not move any misalignment of yoke will cause the cylinder to be consistently misaligned as it turns on yoke tube.

The proper term for the barrel sticking though the frame in this area is barrel extension. People often call it the forcing cone, but the forcing cone is the taper inside the barrel extension. The gap is between the cylinder and barrel extension face.

Occasionally you will find a cylinder that is slightly out of square. But normal end shake should be more than that. I have yet to see one that was .002 out.