Barell

Question
Hello Kyle.
I want to know how the barell lenght of a firearm influence the bullet energy? If the barell is longer, the energy and the accuracy is bigger? For example, there is a big difference between a 4 inch and a 6 inch barell?
I know that the best bullet proof vest can be effective to maximum 44 magnum. But i see somewhere on Internet that there are ceramic plates that can suport 308 winchester (3600 joules energy) without a problem. This plates can be used in kevlar vest?
Thank you.  Andy.

Answer
Andy,

Generally, the longer the barrel on a handgun, the more velocity it will produce and the better its accuracy will be.

When the pressure inside the cartridge case builds up enough to expel the bullet, a lot of gas follows the bullet out of the barrel. A longer barrel gives that column of compressed gas behind the bullet more time to push the bullet faster before the bullet leaves the barrel and the gas dissipates. There isn't a huge difference between a four and six inch barrel, but there is some. The difference gets more noticeable when there's a greater difference in barrel lengths. For instance, a model 66 S&W with a six-inch barrel is going to have consistently higher velocities with the same cartridge than a model 66 with a two-inch pipe.

Longer barrels also lend themselves to increased accuracy. Part of the reason is because the longer barrel is able to put a better spin on the bullet. The other reason is because a longer barrel means an increased "sight radius" the distance between the front and rear sight. Short-barreled guns have a relatively small distance between the front and rear sights, making them harder to aim whereas long-barreled guns are more forgiving.

There really is no such thing as a 揵ulletproof?vest and the makers sell them as 揵ullet resistant?vests. They're able to stop .44 Magnums and similar wide, flat-nosed bullets because the strands of Kevlar are able to catch the flat bullet without the bullet working its away between them. Rifle bullets, which are usually FMJ and have a sharp point, generally slice their way between the Kevlar fibers. To stop those types of rounds, a dense ceramic plate, usually called a 搕rauma plate?is used. Vests featuring trauma plates are quite a bit more expensive than vests without them. The trauma plates themselves are generally worn in an interior pocket in the vest, over the heart and lungs. Like vests, trauma plates are worthless after being shot.

One thing to keep in mind is bullet-resistant vests simply stop the bullet from penetrating into the wearer's body. The hundreds of foot-pounds of energy the bullet generates upon impact are still transferred to the body in the form of blunt-force trauma, made worse by the relatively small point of impact.

Feel free to ask any additional questions.

Kyle