[Tarpaulin]

This happened with a Smith & Wesson!?

That's hard to believe.

Advice: Take it to a gun smith or chuck it.

[patsyde]

Your problem is due to firing 38 specials, which I assume were not jacketed. With the 38 special being shorter then the 357's a lead ring is applied to the mouth of each cylinder. It's enough to keep the 357's from going all the way into the cylinders. A good cleaning with a brass brush will cure the problem.