In small arms we seldom encounter shells. Although shotgun ammunition is referred to as shotgun shells, shell and shot have different connotations with artilleryman and rifleman. Shot, is a solid projectile used primarily in the armor piercing of armored targets. The only effect is kinetic energy. Shells are carriers. Mostly explosives today, but multiple projectiles or gas in the past. They are hollow projectiles used to deliver a payload to the target area. Explosives, gas or smoke.
Metallic Shotgun Shell
In small arms we have a partially metallic shotgun shell that acts as the cartridge, with shot, powder and primer. Because shotguns generally operate at much lower pressures than cartridge firing weapons, the hulls or casings are made of paper and plastics, mostly plastics today. The metallic cartridge contains powder, projectile and primer in a ready to go package. Cartridge brass is made from 70% copper and 30% Zinc. Brass is a copper-zinc alloy. Bronze is copper and tin.
Bullet & Ball Terms
As more legislation in various states limit lead in firearm projectiles, bullets are trending to monolithic designs generally of solid copper. Nothing beats a lead core, but the modern monolithic bullet performs very well. So essentially small arms projectiles are ‘shot’, but we reserve the term bullet to differentiate from the shot or pellets in shotgun loads.
Take the term “ball”. Ball originally referred to the round projectiles fire by muzzle loading rifles since the dawn of firearms. But today in military parlance it refers primarily to a non expanding projectile intended for primary anti-personnel engagements, to differentiate armor piercing and other specialized projectiles from the standard infantry load. However, the standard infantry projectile now has a steel core for penetrating body armor.
Types of Cartridges
About cartridges. There currently standard, intermediate and magnum rifle cartridges. As common combat occurs are ranges under 500 yards, more like a maximum of 350 yards the militaries of the world introduced the intermediate combat cartridge. The first was the German 7.9x33mm round and served as inspiration for the Soviet 7.62x39mm M43 AK-47 round. The idea to go to a lighter round, carry more of ‘em and fire them from select fire fully automatic capable rifle. Nearly everyone uses a .22 caliber variant today, both NATO and former Warsaw Pact. But there maybe a shift towards heavier rounds that will perform better from short barreled carbines for close quarters combat. Nothing like firearms nomenclature exists. Many words are borrowed from the French or Germans who where early leaders in firearms and ballistic sciences. Many words derived and made-up when it comes to cartridge names. And much varies from country to country. But firearms metrics seem somewhat consistent. There is bore, in inches or millimeters, velocity in feet per second or meters per second or bullet weight/mass in grains or grams. So, units may vary but they reference common terms for various firearms related communications. The early years of firearms development has left a legacy to this day. And like all specialized endeavors has developed a unique terminology.