I got on a long-barreled kick in 1980 and ended up with 8 3/8-inch Smith & Wesson Models 14,17,27, and 29.
Ran extensive handloading tests on the center fires using all the "usual suspect" powders through them as well as shorter barrel lengths on hand for the cartridges.
Determined that in the .357 Model 27 2400 provided the most velocity performance with 158 grain bullets, both jacketed and cast over H110, Blue Dot, AL8, Unique, and IMR 4227.
As an aside, H110 turned in the best performance in .44 Magnum. 2400 gave highest velocity in the Model 14 with 158 grain cast bullets. Unique was more kind to the revolver for general purpose use. I did take my first handgun shot deer with the Model 14 .38 Special, a 200 grain lead bullet over a charge of 2400.
In 1982 a "real deal" came up on a new 6-inch Model 27-2 so it came home to roost. I ran the same course of powder tests through it to find that it gave 100-150 fps more velocity across the board than the 8 3/8-inch. The barrel/cylinder gap wasn't the problem. I'd read of "slow barrels" so I assumed the 8 3/8-inch just had a slow barrel. It ultimately went away when I determined that 8 3/8-inch barrels were a bit awkward for some applications.
Back while I still had that long-snouted Model 27 I once holstered it up as the side arm for an evening of varmint calling. A friend and I were in the back of a pickup and I was wailing away on a call. An owl got in our hair and kept on coming so I hauled out all that Model 27 ordnance and used it to flail at him with the barrel. I was young and dumb. I warded him off and we remained unscathed and the Model 27 was none the worse for the wear.
The friend had never been varmint calling that night and was skeptical, but I made a believer out of him, especially after he got a coyote later that evening with his .243.
I'd say 6-inch Smith & Wesson .357 Magnum barrels will extract most all of the goodness out of the .357 Magnum cartridge that one needs to apply to handgun chores.
I kept three of those four long barreled Smith & Wessons as well as the 6-inch Model 27. I have reached that certain age where they are again in favor. In fact, I sometimes wish they had 18 3/8-inch barrels.
