A couple issues with .357 Mag in a self-defense situation you should be aware of are;
the round is a high-velocity round, FMJ/Ball (jacketed solid-point) rounds have a nasty tendency to overpenetrate, go through the target and retain enough energy to still be dangerous, an expanding hollow-point bullet will reduce, but not eliminate, this possibility
full-power .357 Mag rounds are LOUD, REALLY LOUD, especially in an indoor environment***…
Pain threshhold - 140 dB
.357 Magnum - 164.3 dB (a deep BOOM and a supersonic CRACK, with a palpable muzzle-blast)
.38 Spl - 156.3 dB
9mm - 159.8 dB(a sharp supersonic CRACK)
.45 ACP - 157 dB (a low, throaty BOOM)
as a comparison, a 12-gauge round from the standard 28" barrel; 151.50dB
the .357 Mag is one of the loudest cartridges in common use, if you have to fire one in self defense without hearing protection, it’s highly probable you will suffer some amount of PERMANENT hearing loss, even just one round, and we haven’t even dealt with the bright muzzleflash from a revolver with a 4" or shorter barrel
the .357 is an awesome round, no doubt, but it’s overkill for many home-defense situations, my preferred HD/SD cartridge is a .45 ACP with Speer Gold Dot hollow points (thank Og I haven’t had to use it for defensive purposes, and I hope I never have to)
depending on where you live, and the firearm laws in your area, you may or may not need a firearms ID card, I live in Maine, I can simply walk into any store in Maine or NH and buy whatever ammo I need with no need to show any form of ID, and there’s no state limitations on how many boxes/cases I can purchase, unlike my neighbors in the firearm-hating state of Nannychusets, errr…Massachusets…
*** the damage caused by one shot from a .357 magnum pistol, which can expose a shooter to 165 dB for 2msec, is equivalent to over 40 hours in a noisy workplace.