[JG14_Jagr]

With cowl mounted guns the convergence (horizontal) can be set to long ranges as the weapons are mounted in a narrow track and the grouping will be tight regardless of range. For wing weapons its must more critical. If you set the outsode .303's on a spitfire to have a lateral convergence of 100M at more than 200M they will be wide than the wing tips of a 109E

In practice pilots did one of two approaches,, good pilots/shooters usually Point Harmonized their weapons. All the guns were doped to hit the same point in space at a certain range.. if you got that range and got fire on the target it wuld be devastating. Most pilots did an Area (BOX) Harmonization where pairs of guns were doped to impact in a certain area so the effect was a wider hit pattern It was more difficult to get a quick devastating kill, but it greatly increased the chances of getting hits.