riffraff n.

"portable firearm having a barrel or barrels with a spirally grooved bore," by 1775; the word was used earlier of the grooves themselves (1751), and is a noun use from rifled pistol, 1680s, from the verb rifle meaning "to cut spiral grooves in" (a gun barrel); see rifle (v.2).

The spirals impart rotation to the projectile, making its flight more accurate. Rifles "troops armed with rifles," sometimes as part of a unit name, is by 1843. Rifle-range is from 1850 as "distance a rifle-ball will carry" (also, and earlier rifle-shot, 1803); the meaning "place for rifle shooting" is by 1862. Rifle-ball is by 1884; the  word continued in use after cylindrical bullets with conical heads replaced round ones.

late 14c., rafle, "game played with dice, a throw of the dice" (senses now obsolete), from Old French rafle "dice game," also "plundering," a word of uncertain origin. Perhaps from a Germanic source (compare Middle Dutch raffel "dice game," Old Frisian hreppa "to move," Old Norse hreppa "to reach, get," Swedish rafs "rubbish," Old High German raspon "to scrape together, snatch up in haste," German raffen "to snatch away, sweep off"), from Proto-Germanic *khrap- "to pluck out, snatch off." The notion would be "to sweep up (the stakes), to snatch (the winnings)." Diez connects the French word with the Germanic root, but OED is against this.

The meaning "method of sale by chance or lottery, form of lottery in which an article is assigned by the drawing of lots to one person among several who have paid for the chance" is recorded by 1766.