I don't think I've ever seen anyone on any of the forums I'm on suggest that you need a .300win mag, or .300RUM for that matter to harvest deer.
That being said, it is of my opinion, that it's better to bring a little 'more gun' than you might need, assuming you can handle the recoil and shoot the cartridge as well or better than a milder cartridge.
.357 is fine if you put it in the right spot. Well hey, so is .22LR, people have been doing it for years, but I would not recommend that at all, and in many/most places that is illegal. As long as the bullet penetrates sufficiently, and as long as the bullet is put in the right spot, it will kill an animal ethically.
The only danger with .357 is using an expanding bullet that is too light/lightly constructed, where it may stop short of vitals. This danger is somewhat larger with a rifle due to the increased velocity. Use a bullet with decent construction and/or heavier weight, and you'll be fine.
That being said, it is of my opinion, that it's better to bring a little 'more gun' than you might need, assuming you can handle the recoil and shoot the cartridge as well or better than a milder cartridge.
.357 is fine if you put it in the right spot. Well hey, so is .22LR, people have been doing it for years, but I would not recommend that at all, and in many/most places that is illegal. As long as the bullet penetrates sufficiently, and as long as the bullet is put in the right spot, it will kill an animal ethically.
The only danger with .357 is using an expanding bullet that is too light/lightly constructed, where it may stop short of vitals. This danger is somewhat larger with a rifle due to the increased velocity. Use a bullet with decent construction and/or heavier weight, and you'll be fine.