Word is the 3" gun gives 300 FPS less velocity than 8 3/8". For this reason, it may kick LESS than the current version. I ran the numbers and shooting 450s at 1700 in the long barrel and 1400 in the shorty, recoil would be the same if the snub weighed 60 ounces (12 less than the 8 3/8" gun.)
I machined the underlug off a stock gun and threw away the comp; balance is 100% better and recoil only slightly higher. Weight is 63 ounces.
See it at
http://www.john-ross.net/images/Cust500.jpg
I am in the middle of doing a 5 1/2" version, half lug as above, shroud shortened from the rear, barrel from the front, muzzle nut in front a la Dan Wesson.
Hope to show it to Herb and Bret in Vegas. Will be lobbying S&W heavily to produce 5" and 8 3/8" half-lug factory guns with no comps. Comps are useless on revolvers with heavy bullets. Do the math and you will see they reduce recoil maybe 1%-2% but are ugly, noisy, fill with lead, and make the gun an inch longer.
You CAN conceal carry a 5 1/2"-barreled X-frame (500) if you have an IWB holster made that positions the gun so that the entire cylinder is above the top of your pants (top of belt). This makes for comfortable 4:00 position and you can sit in a car no problem.
Have to be very careful with ammo choices to avoid too much penetration. Nylon bullets at 4000 maybe...?
Don't see the point in a barrel shorter than 4" on the .500 but I'll get a 3-incher and tell you guys about it. Comp is replaceable with a solid piece with a hole through it; I'd have preferred a regular 4" bbl.
John Ross