I'm all for dramatically increasing the rarity of firearms and their accompanying ammunition, especially military grade weapons. The OP touched upon something which I feel has gone overlooked in this thread, and that is weapon reliability. Civilian owned weapons can often be ill-treated and therefore prone to failure, while the opposite is true for military weapons found in bases and/or encampments, and I feel the game should reflect this. A weapon degredation and accompanying repair system tied to weapon maintenance would fit this game quite well. Add weapon cleaning kits with limited uses to the loot, and enforce their use to ensure sustained performance from your firearm. Add in weapon repair parts (or kits, for simplicity) for each firearm as they will degrade until unsuable but regular maintenance prolongs this. Also, the Balota airfield should be made entirely civilian.