All barracks, tents, and containers spawn only the SK 59/66 semiautomatic russian rifle. No AK, no M4. I have combed through NWAF, TISY, and MYSHKINO bases, only SK 59/66, twenty-five drops in a row. All the accessories to AK and M4 spawn in absurdly high rates (stocks, grips, scopes, armor-piercing ammo variants), which makes this bug ten times more frustrating, and destroys the impression of rare accessories as, in fact, rare. The loot cycle is being strongly devalued.
SMGs are unaffected, though the UMP-45 seems extremely rare, and Scorpions are incredibly common in police stations now. I found three Scorpions in one station the day before yesterday.
FX-45 have become very uncommon, and the CR-75 has become very common.
The only AK I have found is the one that my character had looted four months ago in the HC (first-person only) stack which I had forgotten about.