Firearm Physics
There exist 3 basic types of portable personal firearms: the handgun, the shotgun and the rifle. Each type of gun has been optimized around 3 basically different types of ammo.
The name "rifle" refers to the spiral grooves in the bore. These grooves serve to impart to the bullet a bit of rotation around the axis of the barrel. This serves to stabilize the bullet along its trajectory. The rifle is meant for shooting at greater distances than shotguns and handguns. The longer barrel enables the charge in the ammo to act for a longer distance and generally longer time than a shorter pistol barrel. The expanding gases produced from the burning propellent act on the base of the bullet during its trip down the barrel. With everything else being constant, a shorter barrel means less range and less overall momentum and energy in the bullet. The job of the barrel is to direct the action of the expanding gases to the bullet and constrain the path of the bullet such that it receives both linear and angular momentum appropriate to the range of target distances. The design of different rifles balances several aspects to be optimized for the purpose of the rifle. In general, aside from the simple fun of personal target shooting, uses for rifles include competitive/Olympic events, hunting and defense/combat. Longer barrels are appropriate for some types of hunting, long distance competitive shooting and sniping. Shorter barreled rifles are appropriate for some other types of hunting, shorter distance competitions and close quarters defense/attack. Shorter barrels are more easily handled in confined spaces like narrow hallways.
Handguns are basically smaller, lighter and have more compact ammo than a rifle. Their compact size makes handguns the ideal choice for personal defense and attack. While not, IMHO, suited for hunting, I wouldn't be without one in areas where bears, wolves and other dangerous predators roam along with my intended game. A handgun is essentially the only choice for CCW and always check your local laws. To achieve anything close to the momentum of a rifle round, a handgun requires a much larger more massive bullet and more powder.
Shotgun ammo contains a number of pellets which are effective over much shorter distances than rifle rounds but are effective for hunting smaller/moving targets.
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Physics is about not only the ballistics but also the basic characteristics of the firearm and its ammo.
Well, you can (deny your biology) but it's generally difficult, problematic and less productive. Humans are omnivores. Raising livestock and farming are the efficient ways to feed people. Some folks feel hunting is a valuable skill and often rewards the hunters immediate circle with a whole season of meat for less than market prices. Rifles have evolved to fit this need. The bow has evolved as well. I'm not a hunter and don't know the fine points of the law or details of taking a game animal.
Practical uses for firearms have for hundreds of years been hunting, defense and war. These activities have driven the evolution of rifles, pistols and shotguns. There has hardly been a device of any description not subject to evolution during its use by hunters and the military. Saddles, pencils, boots, etc. have all evolved, at least partially, from influence due to use by the military. The service rifle evolved during the 1940-1970 time period from the M-1 Garand to the M-16A2. One change was that the M-16 fires in full-auto versus semi-auto for the M-1. Maybe less known is that the M-16 is 10% shorter than a Garand and 33% lighter. 5.56 NATO is also lighter than .30-06.
Much of the evolution of the rifle over the last hundred years makes it easier to carry, more reliable in target acquisition and using more portable ammo. Preferring that civilians avoid these benefits in favor of them having Fudd guns is like asking folks to drive cars designed to Amish specs.
(No bugs, Amish or horses were injured, abused or inappropriately photographed in the writing of this post.)
Always use a pan of the same geometry as noted when following the directions on the box. 
drop the oven temp by 50 degrees to account for increased absorption of radiant energy. 
...dark, glass and flexible baking pans. I work with what I know and am use to. 
you can substitute mayo for recipes that call for equal parts of vegetable oil and eggs.
FWIW, stay away from Miracle Whip. 
And I stay away from Miracle Whip like I avoid shortening 
Mayo is just basically eggs folded into oil. They add some chemicals of course but if you're out of either and need both to make some Drunken Hines rum cake...
