even if it is rated Heaver loads WILL cause faster wear I would go straight to the source (Smith and Wesson) at 1-800-331-0852 - Mon-Fri 8:00AM-6:00PM Eastern Time

The K-frame S&W revolvers were made for the 38 special cartridge. The K-framed Model 19 and 66 had a bad reputation for wearing out rapidly when subjected to 357 magnums. The model 10 with continuous +P use will wear out more quickly than if you used standard 38's. The +P was originally developed for the S&W 38-44 (a hot loaded 38 special that was chambered in a heavy N-frame or 44 frame). Your smaller K- frame will handle it but it will not last as long.

Hi Charles, since this has been a 50/50 question proposition for you, I would go straight to the source (Smith and Wesson) at 1-800-331-0852 - Mon-Fri 8:00AM-6:00PM Eastern Time