Hey LD1/studor, I think the basic point that you are missing is that the bullet must not exit the animal if it is to deliver its full payload of energy. Ever hear of the depleted uranium sabot rounds that are used for tank killing? They are designed to penetrate a thick layer of armour, then release the remaining pure kinetic energy in the interior of the tank. With a proper bullet/powder combination, exactly the same effect is achieved inside a chuck. A mangled bloody mess on the outside may look impressive to you (a little sick if you ask me) but that will put you at a handicap in any chuck contest because of the lost body mass. The more energy absorbed by the chuck, the quicker he expires, it is actually as simple as that. You may be getting a bloodier mess on the outside because of reduced velocity, but not on the inside, where the real damage is done. Slowing a bullet down so that it does not fragment completely and exits is also more dangerous as others have explained. That is my biggest problem with the 223 relative to the 22/250. Those other couple you mentioned that may have a velocity edge on the 22/250 are not worth considering for the average Joe due to scarcity and high cost of ammo. The 22/250 may not be the best chuck gun, but it certainly a good one. Something I can not say for the 223. I put another plug here for the 55 grain hornady varmit express bullets for those of you having exit trouble with 22/250's. Again 99/100 inside under 100 yards aint too bad and I am not exaggerating too much with those numbers. Keeping the shot as close to centered on the body as possible helps a bit also. Good shooting everyone, this is it for me on this thread as we are starting to beat the dead horse now.