impact, causing a larger and deeper wound channel. Some bullets have a web in the center of the bullet to limit the expansion of the bullet while promoting penetration. Some bullets have dual cores to promote penetration. Bullets that might be considered to have stopping power for dangerous large game animals are usually 11.63 mm (.458 caliber) and larger, including 12-gauge shotgun slugs. These bullets are monolithic-solids; full metal jacketed and tungsten steel insert. They are constructed to hold up during close range, high velocity impacts. These bullets are expected to impact and penetrate, and transfer energy to the surrounding tissues and vital organs through the entire length of a game animal's body if need be. The stopping power of firearms when used against humans is a more complex subject, in part because many persons voluntarily cease hostile actions when shot; they either flee, surrender, or fall immediately. This is sometimes referred to as "psychological incapacitation". Physical incapacitation is primarily a matter of shot location; most persons who are shot in the head are immediately incapacitated, and most who are shot in the extremities are not, regardless of the firearm or ammunition involved. Shotguns will usually incapacitate with one shot to the torso, but rifles and especially handguns are less reliable, particularly those which do not meet the FBI's penetration standard, such as .25ACP, .32 S&W, and rimfire models. More powerful handguns may or may not meet the standard, or may even overpenetrate, depending on what ammunition is used. Fully jacketed bullets penetrate deeply without much expansion, while soft or hollow point bullets create a wider, shallower wound channel. Pre-fragmented bullets such as Glaser Safety Slugs and MagSafe ammunition are designed to fragment into birdshot on impact with the target. This fragmentation is intended to create more trauma to the target, and also to reduce collateral damage caused from ricocheting or overpenetrating of the target and the surrounding environments such as walls. Fragmenting rounds have been shown to be unlikely to obtain deep penetration necessary to disrupt vital organs located at the back of a hostile human. Wounding effects Physical Permanent and temporary cavitation cause very different biological effects. A hole through the heart will cause loss of pumping efficiency, loss of blood, and eventual cardiac arrest. A hole through the liver or lung will be similar, with the lung shot having the added effect of reducing blood oxygenation; these