My younger boy was a but recoil sensitive.. so he started with, and still used a .223 savage axis. He has shot 4 with it, and ive shot 2 with the AR in .223. In our limited sample of 6, one ( liver/lung hit) ran 70 yds, the rest have all been 20-40 yds traveled and down. He of course uses mostly broadside center- lungs hold. I have made a point of using solid copper or bonded bullets to help ensure an exit even on more quartering hits. ( and even with shoulder bone or exits behind the diaphram, they have exited) this is important, because even with .30 cal- sometimes they run. We have used barnes copper 62gr, Wincester factory “ boar xt” solid copper hp, and fed fusion/ gold dot factory 62 gr. I have also shot a couple smaller pigs with the fusion load. By the wound channels you would not think they were .22 diameter bullets. Based on our limited sample i’d have no issues using .223. I do recomend if you cant find copper solids like barnes, or bonded, partition, etc- then at least get sp like the powerpoint, 65gr gameking that are marketed as a medium game bullet..