I had a squib 38 special load once in my Ruger Bisley Vaquero 357 and didn't realize until the next round because they were light rounds anyway. The shot felt fine, but kicked weird and I heard two bullets hit the target board. Didn't really hurt the gun, except for ringing the barrel. I didn't even notice that until I cleaned it that night and felt a small part of the barrel that didn't have the same resistance on the cleaning patch. I check with a bore light confirmed it. Could only see it on the outside by looking longways down the barrel to see the slight budge. I shot that gun for many more years like that, and accuracy didn't suffer. I was very lucky.
I was told 38 wadcutter with Bullseye powder has blown up more revolvers than any other caliber. I think I believe that.