If you fire a machine gun continuously for over 5 secs, the barrels start to overheat. This results in rapid barrel wear and eventually bending, which will throw off the aim very quickly.
Here's a quote from the FAF (finnish air force) war time test reports on 12,7mm (50cal) machine guns:
"To prevent the barrels from overheating, short bursts of 15-20 rounds had to be fired. Firing with a hot barrel resulted in an arced bullet flight path and bad accuracy."
The usual firing range for finnish pilots in WW2 was under 150 yards. Most pilots got well under 100 yds before firing. I started to think about "bad accuracy" at these ranges... The bullets really have to arc a lot to miss the target at that range. I'd say 20 degrees or even more...
Presently in any flight sim, I can fire my guns continuosly until I run out of ammo, and the bullet stream stays straight as an arrow.
...interesting...
Camo
------------------
Camouflage
XO, Lentolaivue 34
www.muodos.fi/LLv34 "The really good pilots use their superior judgement to keep them out of situations
where they might be required to demonstrate their superior skill."