Here's some stats from Buffalo Bore that you may find helpful...
About Buffalo Bore 357 Mag. ammo
Our 357 mag. ammo adds more power than ever before to the 357 mag. This ammo is safe to shoot in ANY all steel 357 revolver—this includes J frames. This ammo is no harder on your gun than any other normal 357 ammo. Please don’t phone us and ask if this ammo is safe in your gun. It is, providing your gun is in safe condition for use with any normal 357 ammo.
We don’t recommend this ammo to be fired in super light alloy revolvers as bullets may jump crimp under recoil, but the ammo itself wont hurt these super light weight revolvers. These revolvers are simply so light that the recoil is severe enough to cause crimp jump.
The below velocities are offered so that you can see what guns/barrel lengths give what velocities with this new 357 mag. ammo. You’ll notice that new S&W revolvers with short barrels are often shooting faster than older S&W revolvers with longer barrels. The new S&W revolvers are very good and are made with equipment that makes them more consistent and faster than the S&W revolvers of yesteryear.
Make special note of the Marlin 1894, 18.5 inch barrel velocities. Item 19C/20, supercedes 30-30 energies!!!
1. 3 inch S&W J frame
a. Item 19A/20-180gr. Hard cast LFN = 1302 fps
b. Item 19B/20-170gr. JHC (jacketed hollow cavity) = 1299 fps
c. Item 19C/20-158gr. Speer Uni Core = 1398 fps
d. Item 19D/20-125gr. Speer Uni Core = 1476 fps
2. 4 inch S&W L frame Mt. Gun
a. Item 19A/20-180gr. Hard cast LFN = 1375 fps
b. Item 19B/20-170gr JHC = 1411 fps
c. Item 19C/20-158gr. Speer Uni Core = 1485 fps
d. Item 19D/20-125gr. Speer Uni Core = 1603 fps
3. 5 inch S&W model 27
a. Item 19A/20-180gr. Hard Cast =1398 fps
b. Item 19B/20-170gr. JHC = 1380 fps
c. Item 19C/20-158gr. Speer Uni Core = 1457 fps
d. Item 19D/20-125gr. Speer Uni Core = 1543 fps
4. 6 inch Ruger GP 100
a. Item 19D/20-125gr. Speer Uni Core = 1707 fps
5. 18.5 inch Marlin 1894
a. Item 19A/20-180gr. Hard Cast = 1851 fps
b. Item 19B/20-170gr. JHC = 1860 fps
c. Item 19C/20-158gr. Speer Uni Core = 2153 fps---- Can you believe this?!!!
d. Item 19D/20-125gr. Speer Uni Core = 2298 fps---- Or this?!!!
http://www.buffalobore.com/ammunition/default.htm#357