Their is alot more that plays into killing a deer than the size of the bullet or how much energy it has , Proper bullet placement has a realy big part as does a reasonable amount of energy but saying that you realy need 1000lbs of energy to cleanly kill deer is totaly ignorant. Hydrostatic shock is the biggest killer when it comes to taking game unless you shoot the spine or brain. If you shoot a 200lb buck at 100yds broad side , centered through the ribs with a 223 factory loaded 64gr Winchester powerpoint , he is gonna die quickly no if and or buts about it , make that same shot on the same animal with a 50BMG and a 671gr FMJ ball round and he will run off likely a pretty good ways despite having several several more TONS more energy , why , bullet performance , the 64 gr powerpoint is going to expand and fragment slowing down very fast leaving most if not all of the energy is makes in the animal , their for you have a perfect Kenitic energy transfer than sends a shockwave through the animal effectivly shutting down its organs and nervous system.
Now the huge 50 cal bullet is generating WAY more energy but the bullet desgine is not going to allow it to deposit hardly any of that energy its just gonna poke a 1/2" hole through him , granted that 99% of the time if you poke a 1/2" hole through both of an animals lugs he is gonna die but he is going to die of suffication which can take several minutes and a deer can go a long **** way in 60 seconds !!!
I have personaly seen several deer shot perfectly with guns ranging from 7mm through 338 win mag but the bullets used were desgined for big game soe the expansion and energy transfer was minimal on the relitivly speeking small deer so that ran a long way before expiring on the same note I've seen deer shot with 80gr soft point bullets out of a 243 not go 20yds after being shot and the bullet rarely exited so all the energy was expended in th animal.
A rounds power and effective killing power are to differant things , with the proper bullets just about all common centerfire rounds will cleanly kill and do so fairly quick , but the same rounds loaded with bullets desgined for massive penitration isin't going to be as effective.
Down here their is alot of good ol boys that think that you have to have a magnum round to kiil deer "waayyy out their" meaning 400yds. I've gotten is argument after argument about the guns I use not being effective , despite taking these guys money on bets that they wittnessed , one being a doe taken at a lasered 618yrds with a factory loaded 308 , a doe taken at around 100yds with a factory loaded 223 round ouit of a 14.5" AR-15 , both cases the deer went less than 40yds. I shot a doe at around 200yds with a hot loaded 22-250 Ackley , a 50gr bullet at over 4000fps behind the shoulder, the deer just fell over like sombody unpluger her never kicked or took another step , in this case the bullet never even made it into the off side lung yet it was completely destroyed as was the heart and neither was ever touched with anthing more than a hydrostatic shock wave.
The same thing goes for people thicking that they have to have big handguns to use for self defense , as long as the bullets were desgined to do the job then the round will work , case in point A walther PPK loaded with a Blue Glaser round will kill a man VERY fast put him down in just 2-3 seconds with a center mass hit yet a man shot 10 times with a 45ACP and 230gr ball rounds in the chest and abdomen was able to run several blocks before dieing , but the 45 ACP is noted as being a "man stopper" and the 380 is a marginal womans gun not even on par with the 22 mag. But the Glaser round was desgined to stop and man ASAP and the ball round from the 45 was not.
so with the proper bullets for the task at hand the 223 will kill deer very well at ranges within reason for this round , say 200yds max. Are their better rounds for the job , yep , would I choose another round if that option is availabe , yes. But if a fella gets a great deel on a H&R handi rilfe in 223 and that is the only thing ha can afford at the time they all he needs to do is get some decient bullets and make decient shots and their will be little to no worries.
