"Standard to the 190A5 are a pair of cowl mounted 7.9mm MG17's with 900 rounds/gun. That's a lot of ammunition and considering they were cowl mounted the concentration of fire is generally good at any range (set the convergence out to maximum) providing a bit of longer ranged touch just to keep people honest. Also standard are a pair of Mg151/20 cannons with a generous 250 rounds/gun, double the average ammunition of similar mountings. The Mg151/20 are good weapons though they can take some getting used to ballistically if you aren't familiar with them (or have been using US .50's or hispanos a lot). Considering the amount of ammunition involved though, the 190A5 has excellent staying power and is one of the few aircraft that tends to run low on fuel before running low on ammunition. The basic firepower is more than enough to deal with most fighter-sized targets quickly and effectively and there is no need to be shy with your shots as you have lots of ammunition. There is only option available to add another pair of 20mm cannons although it may not be as good an idea as it seems. The extra cannons are MG-FF, an older 20mm design, and the ballistic properties are clearly inferior for the MG-FF vs. the Mg 151/20 not to mention the ammunition load-out for the extra cannons is only 60 rounds/gun."