Change Ordered Quantities and Quality caps at 300

Every time I try to set my ammunition Change Ordered Quantities and Quality to 350 as soon as you push Save the game puts it back to 300.

There is hardly any ammunition on the market at Q350. The max is drifting to Q300.
It might be there now, in extreme conditions but Q>300 is disappearing from the market.

ordering Q350 can under some conditions make you pay too much while the quality you receive will never be 350.

The only way to produce Q>300 (300 does not make sense.