Like the man said a 357 burns slower powder to achieve muzzle velocity and even through a 6" barrel it fails to burn all the power. Just look on the ground at the ranges after firing a box and you will see a lot of unburned powder on the ground or bench. A 357 in a 3 or 2" barrel is a waste as far as performance goes and a sure fire way to lose your night vision for some time if you really need to defend yourself in the dark.
Secondly and that is nobody should be carrying a defense pistol/revolver with re-loads or their own loads. In the house perhaps but not in carry. If you should have to defend yourself and even if all your ducks are in a row custom loaded ammo is like giving the DA a free pass to paint you as somebody who was more interested in doing harm than protecting. In lethal force situations you want to be A-1 squeaky clean citizen only trying to protect yourself, your family and property. You may prevail in court but at what cost — all your savings and money cause the DA thought he could sell you to a jury as a something evil or predatory. It's just is not worth the risk and honestly really does not accomplish much if anything that good factory loads will give you.
I recall Mas Ayoob in his training sessions drilling this into everybody. DO NOT USE RELOADS IN YOUR CARRY GUN. Then he proceeded to read courtroom testimony during X-exams where even police officers with their own off-duty carry guns were getting crucified. Enough said