Best deer cartridge? That is kind of a who knows question. Any rimfire is a bit light, but, ok under carefully contolled conditions such crop damage control. They work great for finishing wounded animals also. At the other end things such as 458 win, 460 Weatherby, any of the big British cartridges, and 50 bmg are a little over the top. Anything in between should do the job. Specific conditions can play into it of course. If I had to walk into a gun shop and just grab a rifle it would be minimum 24 cal with 100 grain bullets and maximum cal of 35. Any thing in that range could arguably be the "best deer cartridge"
