Interesting how a .243 thread is turning into a ballistics discussion
I think youre both right. Again, this is an over-simplification. Rapid death is brought about only by brain death, either through direct trauma to the CNS (Central Nervous System) or indirectly by depriving it of oxygen (Circulatory System). The large deep wound channels that Harvester alluded to result in cardiac arrest or hemorrhaging the resultant loss of blood pressure completely shutting down the circulatory system and the supply of oxygen. As MH stated, the violent pressure wave that accompanying a bullet passing near the CNS is also enough to often provide adequate trauma to the CNS resulting in brain death.
The one thing that I have to respectfully take issue with is the idea of neck shots something that I see crop up often when the .243 is discussed. It is true that a bullet severing or passing near the spine or carotid artery (the only two vital targets in the neck) will provide brain death. However, to attribute this effect to a certain cartridge or bullet is a mistake. It is also true that a bullet path that is just a couple inches lower will have no such result. If the spine is missed, a neck shot animal will be maimed. Because a deer so frequently and rapidly moves its head/neck, it does not lie within the skill of most hunters to make this a reliable target. Add to the variables known trajectory/distance, wind speed, a steady rest
and the shot becomes even more irresponsible.
Back to the issue
There is no best cartridge. All calibers and their bullets have their attributes and their shortcomings. The key is to match these with the hunter and the quarry. If youre a highly seasoned hunter who has the restraint and patience to pass on marginal or raking shots, then yes, the .243 is a fine round for you. It is flat, and when placed properly will result in consistent kills.
My gripe is with the trend of recommending this as a starter rifle for a new hunter. These hunters more often than not, lack the experience and skill needed to place every shot without fail. A heavier, larger caliber bullet provides a larger margin for error - period.
Bryce Towsley:.
"As a deer cartridge, the .243 Win. is nothing if not controversial. It's often selected as a "first gun" cartridge, and I suspect that's where most of the controversy is rooted. The .243' nearly quarter-inch bullet is adequate for deer hunting, but it doesn't carry much insurance. The little quarter-bore has almost no forgiveness built in as compensation for a poorly placed shot, and a new hunter is far more likely to place the bullet imprecisely than is an experienced hunter."
Very well said in my opinion. I am not trying to argue the legitimacy of the .243 as a deer rifle. It is certainly up to the task. However, I must take issue with the notion that it is the best deer rifle. It is also worth while to consider its limitations.