Not to go all conspiracy theory, but . . . coronavirus.
Crossbow. Knives.
“...the baddest mother of them all: the legendary M82A1 Barrett .50 cal...fires the...BMG round...introduced in 1921 as a scaled-up version of the .30-06 hunting round... airplanes. The BMG went on to widespread use on fighter planes...a bolt-action rifle like this, it’s capable of punching big holes in engine blocks from more than a mile away. The longest known confirmed hit was taken in 1967 by a Marine sniper in Vietnam, and he still holds the record at 6,558 feet...doesn’t so much “kill” as “vaporize.”...” [from original article]
The authors got most details on the 50 cal wrong.
30-06 was introduced in 1906 by the military and only later gained popularity among civilian users.
It was developed for use against armored ground vehicles, not against aircraft. Its use in the anti-aircraft role and as aircraft armament came later. Even at the outset of WW2, it was recognized that aircraft guns firing inert (nonexploding) projectiles were becoming marginal.
The Barrett M82 (DoD nomenclature M107) is not a bolt action, it’s a recoil-operated semi-auto.
All long-range hits from the Vietnam period have been bettered by later snipers.
The 50 cal round is not the final word in long-range sniping. More modern rounds such as 408 Chey-Tac have greater effective range.
50 cal bullets damage targets by transferring energy. Vaporizing doesn’t happen.
The “Q-ships” pioneered by Britain in WWI (and used in both wars) was smart; they armed merchant ships with concealed weapons and when the German sub surfaced to sink it they’d blast it - once the sub couldn’t dive due to holes, it was outgunned by the weapons of the Q ship.
A lot of people think torpedoes were the primary weapon of the U-boats, but the deck gun was the intended main weapon for sinking cargo ships (much more economical - they could carry far more shells than torpedoes).