Soulja Boy's stupidity knows no bounds -- the rapper recently posted photos online prominently featuring high-end sizzurp ... just days after his gun arrest, and judging by his choice of codeine cough medicine, Justin Bieber would be proud.
TMZ broke the story ... Soulja got busted a couple weeks ago for having a loaded gun in his car.
You'd think that would scare him straight -- but last week, Soulja Instagrammed photos of himself sitting beside a GIANT bottle of Actavis brand cough syrup ... the same high end brand Bieber chugs.
Also notice ... the bottle of Sprite, a very common sizzurp mixer. And the double Icee cups.
As we reported, a large bottle of Actavis runs about $800 on the street -- sans prescription.
Soulja and sizzurp have a history of boneheaded moves -- last year he posted Actavis photos just days after Lil Wayne nearly died from an OD.