![]() How could a gunshot wound have caused this much damage? The organ looked like an overripe melon smashed by a sledgehammer, and was bleeding extensively. I was looking at a CT scan of one of the mass-shooting victims from Marjory Stoneman Douglas High School, who had been brought to the trauma center during my call shift. There may be bleeding and some bullet fragments. To a radiologist, it appears as a linear, thin, gray bullet track through the organ. In a typical handgun injury, which I diagnose almost daily, a bullet leaves a laceration through an organ such as the liver. I thought that I knew all that I needed to know about gunshot wounds, but the specific pattern of injury on my computer screen was one that I had seen only once before. The history simply read “gunshot wound.” I have been a radiologist in one of the busiest trauma centers in the United States for 13 years, and have diagnosed thousands of handgun injuries to the brain, lung, liver, spleen, bowel, and other vital organs. There is also a significant advantage in not having to carry explosive propellant and even the projectile internal charges may be eliminated due to the high velocity - the projectile becomes a strictly kinetic weapon.As I opened the CT scan last week to read the next case, I was baffled. ![]() With railguns, a constant acceleration is provided along the entire length of the device, greatly increasing the muzzle velocity. There is much interest in modernizing naval weaponry by using electrically driven railguns, which overcome the limitations noted above. This length ratio maximizes the projectile velocity. ![]() Large naval guns will have length to diameter ratios of 38:1 to 50:1. Given a long enough barrel, there would eventually be a point at which friction between the bullet and the barrel, and air resistance, would equal the force of the gas pressure behind it, and from that point, the velocity of the bullet would decrease. As the bullet moves down the bore, however, the propellant's gas pressure behind it diminishes. For this reason longer barrels generally provide higher velocities, everything else being equal. Longer barrels give the propellant force more time to work on propelling the bullet. ![]() A balance between propellant quality and quantity, projectile mass and barrel length must be found if both safety and optimal performance is to be achieved. In a gun, the pressure resulting from the combustion process is a limiting factor on projectile velocity. A faster burning propellant may accelerate a lighter projectile to higher speeds if the same amount of propellant is used. ![]() A slower burning propellant needs a longer barrel to burn completely, but can on the other hand use a heavier projectile. In conventional guns, muzzle velocity is determined by the quality (burn speed, expansion) and quantity of the propellant, the mass of the projectile, and the length of the barrel. The velocity of a projectile is highest at the muzzle and drops off steadily because of air resistance. 204 Ruger, all the way to 5,700 ft/s (1,700 m/s) for tank guns firing kinetic energy penetrator ammunition. Muzzle velocities range from approximately 400 ft/s (120 m/s) to 1,200 ft/s (370 m/s) in black powder muskets, to more than 4,000 ft/s (1,200 m/s) in modern rifles with high-performance cartridges such as the. Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. ![]()
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