How is it "not enough gun?" It puts a hole through vitals just the same as any other bullet. In my experience, I have never known, or heard of, a 223 round of any type "coming apart" without penetrating and causing non-lethal damage to a deer, not with any ammunition made in the last decade anyway.

I suppose you could rely on shooting lead pumpkins to make up for shot placement and judgement and hope you mangle the insides of the deer well enough that it eventually bleeds out, but I would rather use the rifle I'm most accurate with at a given range. Depending on where I'm hunting I'll take out the 223 or the 30-06. I don't feel one is more lethal than the other. I'm simply more comfortable with each in different circumstances.

Especially in hunting, there's a lot of old, and... dubious, information that still gets shared as truth. I believe the 223 debate is a wonderful example of this. Sure, I'm biased as I hunt with the caliber, but I cannot remember talking to someone who has who still thinks the 223 is somehow inadequate for humane kills on deer.

All I can tell you in the end is that myself and others I hunt with use all types of HP and SP 223 and 222 ammunition (both the super special and brightly advertised "hunting" rounds as well as typical factory ammo) and that we have the same confidence in the caliber that we have any other that it will kill any deer we come across quickly and cleanly.