"person skilled in gunnery," 1778; see artillery + -ist. Artilleryman is from 1630s. Middle English had artiller "maker of arms" (mid-15c.), from Old French artiller.
Entries linking to artillerist
artillery n.
late 14c., "warlike munitions," especially ballistic engines, from Anglo-French artillerie, Old French artillerie (14c.), from artillier "to provide with engines of war" (13c.), which probably is from Medieval Latin articulum "art, skill," a diminutive of Latin ars (genitive artis) "art." But some would connect it to Latin articulum "joint," others to Latin apere "to attach, join," and still others to Old French atillier "to equip," altered by influence of arte.
Originally any engine for discharging missiles (catapults, slings, bows, etc.); the modern restriction to "ordnance, large guns" is from 16c. Technically, "all firearms discharged from carriages," as opposed to small arms, discharged by hand. As a branch of the army, from 1786.
-ist
word-forming element meaning "one who does or makes," also used to indicate adherence to a certain doctrine or custom, from French -iste and directly from Latin -ista (source also of Spanish, Portuguese, Italian -ista), from Greek agent-noun ending -istes, which is from -is-, ending of the stem of verbs in -izein, + agential suffix -tes.
Variant -ister (as in chorister, barrister) is from Old French -istre, on false analogy of ministre. Variant -ista is from Spanish, popularized in American English 1970s by names of Latin-American revolutionary movements.