I honestly do not think I have seen a more INCORRECT statement ever typed on this site. Hydrostatic shock is absolutely just as detrimental to a hog as it is on ANY animal. And the speedy little .223 does a hell of a lot more damage than some seem to think. With the properly constructed bullet it can drop a hog just as cleanly and quickly as my .458 SOCOM. Now granted my .458 is going to leave more impact damage but if placed properly that little .223 does more than enough to kill a hog. Would it be my choice for a regular hog rifle? Nope, I have several hog rifles that are better suited for my needs such as a 6.8SPC AR, a 7mm/08 LR, the aforementioned .458 SOCOM and a new .338FED LR. Dropped a thousand or so hogs with that 6.8, several hundred with that .458, few hundred with the 7mm/08 and haven't gotten the new .338 out to the hog spots yet. Not to mention the hundreds dropped with my .30/30, .45 colt, .220 SWIFT, .22-250 (those 2 ya stickum in the ear ) .500 S&W, .44 mag, .357 mag, .45/70, various muzzleloaders, 12 gauge (slug and buckshot) and the list goes on.

Based on the OP's options, because of factory ammo availability for both the .223 and the X39 with poor choices really for hunting for the X39, the .223 is probably his best option for now. If he ends up liking the sport and wants to get into it with another choice he can then visit better options for a hog rifle.