James: I think the ammo companies can answer this for you (Rem, Win, Speer, Fed, Hornady) as there is snubby-designed ammo out there. Back in the '80's I did a lot of chrono experimenting with this question, but it was all with handloads, and I tailored my loads to the short barrels (.38, .357 & .44,) so it won't answer this question. I think, only my opinion, that if you use snubby-designed ammo, you'll find the same advantage to the .357 as in ammo designed for longer barrels: bigger case, more powder, more power. This'd be an interesting experiment to try, but my answer to your question would be yes, with proper ammo the .38+P will lose as much in a snubby as will a .357, or put another way, will have the same disadvantage. I'd think that it'd be possible to carry a snubby .357, with non-optimal ammo, that had less power than a snubby .38+P that carried optimal ammo (by optimal I don't mean gimmicky bullets, I mean standard JHP's but with barrel-length-tailored powders.) Phil E