I killed a deer with a M1 carbine. Not my choice but I was in social corner. I was guest at a deer camp in WVa mountains. I was hunting with a Remington 141, 35cal. Host had nice 30carbine and wanted to switch rifles for the day. So I did and shot a fork buck at about 40yds with Win JSP. It ran about 15yds into a tree and end of the story. There is better deer cartridges but I would say 50yds would be my limit on deer. Guys make my butt tired. One bunch needs a 45/70 or 300mag, the others praising a 223. To tell you the truth if you are hunting from a stand you can use a 22rf. But if you are jump shooting deer they are no good. 30carbine will do just fine for dad as long as he can put them in kill zone.