Doubletap Ammunition 40 S&W 125 Grain Barnes TAC-XP Hollow Point Lead-Free Box of 50 - Midway has them. Sorry, I should have been more specific.
Caliber: 40 S&W
Bullet Weight: 125 Grains
Bullet Style: Barnes TAC-XP HP Lead-Free
Case Type: Brass
Muzzle Velocity: 1390 fps
Muzzle Energy: 536 ft. lbs.
Their .357 Sig- is 125 gr at 1450. (584 ft. lbs).
Like I said, I don't see much difference in them. I would have to see an apples to apples comparison of .40 SW 125 gr to .357 sig of the same weight to be convinced. .357 sig might go in a half inch deeper, .40 SW will make a slightly bigger hole the length of the wound. Either one should be an excellent round. I have read some of the lighter rounds of .40 break apart, but there are also reports of .357 or even .357 Mag doing the same thing. With well designed bullets, this should not be a problem.
My comment about not wanting to shoot .357 at 1600 FPS is because of muzzle flip and time to reacquire my target. You might be a much better shooter then me, so it might not be much of an issue for you.