Well now. I just finished testing (seat of the pants) The Buffalo Bore 19E "Lower" Recoil/Low Flash ammo in a 3" Kimber K6s. It appears to be loaded with a Hornady 158 gr. XTP. I fired 48 rounds at 30' all double action and I did not attempt to stage the trigger, just straight pull through. I was able to keep all rounds navel to upper chest and well centered left and right on the standard ATF silhouette target. I fired double taps with about 2-3 seconds between sets and did not lower the revolver until it was time to reload.
I am not recoil shy but 8 cylinders full was enough without risking a sore hand.
I "perceived" the felt recoil to be less than the .357 Mag. WW 145 gr. Silvertips, posted MV of 1,290 (536 ft. lbs.) barrel length unknown, I have been shooting but not by much.
BB posts a MV of 1,172 (481 ft. lbs.) from a 3" S&W M-65 with the 19E load which is 23 ft. lbs. more than their .38 Spec.+P FBI LSWCHP-GC with a posted MV of 1,143 (458 ft. lbs.) from a 3" Ruger SP101 with the 20A load. The .38 load seems to shoot "softer" than what the numbers would lead you to believe...might be the cast bullet...
Positive: The Hornady XTP has a good reputation for penetration and this is the cleanest .38/.357 factory ammo I have ever fired, ever, and I have fired thousands of rounds On an overcast day on a covered firing line there was no distracting flash firing with both eyes open.
Negative: This is most likely the lowest MV which will give any expansion from a readily available JHP. You can change weight and velocity but its an endless spiral chasing "enough" to give the energy, expansion and penetration to get the job done. But in a light weight, short barreled gun it is still a bit too much...
We need the Rim Rock LSWHP loaded to 950-975 fps from a 2-3" barrel in both .38 Spec and .357 Mag.
Best and good luck to you all.