The story
From "the rifle is fine" with the definite article removed, imitative of the stereotypical English mistakes that a native speaker of a Slavic language may make, as most Slavic languages do not use articles. Originally an internet meme popularized in a series of copypastas, posted in 2010 on the 4chan board /k/ (Weapons) by a user under the name "Ivan Chesnokov," facetiously decrying other users for wishing to add aftermarket accessories to their Kalashnikov rifles. The original Ivan Chesnokov spawned a number of imitators and humorous derivatives that helped popularize the term on 4chan and on firearm-focused communities elsewhere on the internet.
Etymology from Wiktionary, CC BY-SA 4.0.