I've owned quite a few Model 10s. I've still got a few. Obviously, I don't own a pressure test barrel. But by estimating between .38 special load data and .357 data, I'd guess that most of my loads fall somewhere between 25,000 and 27,000 CUP. I load .357s at about the same pressure.
That's just what I consider a proper load for a post war K frame .38.
They're warm enough to be a fairly effective load but not so hot that they gas cut the top strap like a full power .357 will do.
