Sure, a 22LR will kill a deer, but that's not the point. Any rifleman worth his boots knows this, and will not use unsuitable calibers for game animals. Does the term "controlled expansion" mean anything?
All it takes is less than optimum conditions, or have the animal move slightly just prior to trigger release, and you've got a superficial flesh wound on a game animal to run off. As for "vital hits" on game animals running off, well, they must be very unique animals as Hutch45 noted.
Either that, or you're shooting puppy-sized whitetails. Our mule deer here on the Oregon high desert, or the big mulies we have up in my native BC would be hard pressed to die with a body shot from a 32gr varmint bullet out of a 204. Be smart, use a proper caliber for a worthy game animal and use your varmint rifles for varmints.
Think about this: the 204 is a sub-caliber cartridge, designed specifically for and only for.....varmints. It was never intended for big game of any kind. Our military uses the 5.56mm (223 Rem) in the M16 and M4 carbines, but also realizes that for dependable man-stopping, more is needed, hence the 6.8 SPC and the 7.62 NATO. The 30-06 and 7.62 (.308 Win) have been used to kill men in combat past 1,000 yards, but the little 5.56mm is seldom used much past 300-400 yards n combat, and this is why they developed fast twist barrels to shoot heavier bullets such as the SS109 from the M16 platform. The mlitary knows light bullets are poor killers, especially at extended ranges in small bores. The bottom line is: use adequate calibers with proper bullet weight for the game intended. A 204 bullet is NOT a game bullet, period! Ever heard of Robert Ruark, noted African hunter of great fame? His words: "Use enough gun"....you newbies with two or three deer under your belt could well heed those words before grabbing your 204 Ruger to go after Whitetails. Okay, rant over, but let's try to be ethical about the taking of game animals, okay?
