What determines first-shot accuracy in CS2?

Each weapon has a unique first-shot inaccuracy value. The AK-47, for example, lands roughly 97% of opening shots on a head-sized target at medium distance. The M4A1-S edges ahead of the AK-47 in standing first-shot precision. For the tightest possible spread, scoped rifles like the SG553 and AUG lead the category.