Taylor and Ayoob believe that 4" barrels do not generate sufficient velocities for the JHP to reliably expand.
From The Gun Digest Book of Combat Handgunnery 4th ed., by Chuck Taylor, page 66:
"Currently, many feel that the 125-grain JHP is the most effective .357 load now available. However, it too needs a longer barrel to achieve velocities sufficent to allow reliable bullet expansion. A speed-loader full of them looks good, but they may not work like you want them to unless you pack a long-barreled gun."
And from page 76:
"The .357 Magnum is at it's best from at least a 6-inch barrel... Once the barrel lengths fall below 6 inches, the .357 loses it's magic."
And from page 202:
"The classic 1500 fps (158-grain bullet) claim of the .357 was obtained with an 8 3/8-inch barrel. This same load rarely produces 1100 fps from the 4-inch tubes typical of today. Velocities in this range are insufficient to produce reliable JHP/JSP bullet expansion..."
On page 105 of the 5th edition of the same, by Massad Ayoob, the author talks about the merits of the .38 +P 158gr LSWCHP:
"Because there is no copper jacket that has to peel back, a design feature that seems to require considerable velocities to work, the soft lead seems to open up even when fired at lowered velocity from short barrels and even when fired through heavy clothing."
Based on this information, IMHO a good choice for the 4" .357 would be the 158gr LSWCHP. You get 25-30% increased velocity over the .38 +P, and you don't have to worry about the jacket expanding. YMMV.