I've only heard it pronounced "primmer" by older people - those about my (now deceased) granparents ages (90 - 94). No idea why they did it this way. I always thought it was the olde English way. Maybe it was just a mispronunciation that caught on.

My grandpa also said "EYE TAL yun spaghetti."

My own weirdness is arithmetic, which I learnt to pronounce as arith MA' tic when used as an adjective. I recall my teacher (among the best I ever had) specifically telling us this.

So as a noun, a rith muh TIK'
and as an adjective, a rith MA' tik (short A in MA)

(as in a rith MA' tik progression)