-Grenades and artillery shells are not commonly designed to cause damage with the blast wave caused by their detonation (though this can certainly be deadly, its casualty radius is small as the force of the blast dissipates quickly). Typically, an anti-personnel grenade or general-purpose artillery shell will rely on shrapnel (small metal pieces of the casing sent in all directions by the explosion) to achieve damage. The iconic "pineapple" grenade used by American infantry in WWII originally relied on its casing to fragment into shrapnel (hence the scoring on its surface), but its fragmentation pattern proved too inconsistent; contemporary frag grenades generally consist of a thin outer shell, and just beneath it, a good length of segmented wire wrapped around its explosive core, which results in an even pattern.
-While the Barrett M82A1 (the most commonly depicted .50BMG rifle) is frequently seen in works of fiction being used like any other sniper rifle, in actuality it weighs thirty pounds, making it very difficult to fire accurately while standing.
-The primary weapon of the A-10 Thunderbolt (known as the "Warthog" for its relative ugliness for a turbine-powered aircraft) is a tremendously powerful rotary cannon that fires 30mm depleted uranium shells. It can only fire a continuous burst for eight seconds before it will begin to melt. It is scary as fuck. (1:10)