I don't know why people here keep saying the Lewis had a slow rate of fire!!!!
According to my data source (Ritterorden website) the Lewis looks like the following:
Barrel:26.25in, 4 grooves lefthanded twist
Magazine (aerial): 97 rounds
RATE OF FIRE:550 rpm
The comparable data for the Vickers/Maxim/Spandau is:
Manufacturer: Vickers Armstrong/Spansau Arsenal
Barrel:28.5in/28.3, 4 grooves righthanded twist
Magazine (aerial): 400-500 rounds per belt
RATE OF FIRE:450 rpm
What people try to adjust/account for is the Lewis gun reload time!
Well friend if your locked in an aerial combat and your gun jams or you run out of ammo and need to reload, you better hope your in the FASTER of the two machines so you can DISENGAGE and fix your problem with no one on your six firing his fully loaded / unjammed machinegun at you!!!!
There is no way you can ASSUME you could reload and restart firing of the Lewis gun while locked in combat(I speaking of the single seat scout aeroplane). A rear seat observer could of coarse reload.
So the actual ROF for the Lewis is 550rpm/9.2rps. A good gunner pilot would probably have a 1-2 sec window to fire a BURST at the flying/moving target ahead of or crossing in front of his SIGHTS.
This means if he's using 2sec bursts that he can fire the Lewis gun 10.5 times before running out of one drum of ammo. Or if he's an expert shot and only uses 1sec bursts he can fire 21 times.
WELL, if he's in a single combat sequence that takes more then 21 bursts from his Lewis gun and more then 33-66 bursts from his Vickers gun he better consider getting !@#%^&* out of DODGE (as they say)!!
A game or sim should allow one to fire the Lewis gun 10-20 times each combat sequence at which point it is out of ammo and cannot be used until the plane is disengaged (completely) and has time to reload.
Slowing the rate of fire is not really how it was DONE!!!!
P.S. the actual rate of fire of the Vickers/Spandau was somewhat slower then the reported 450rpm because of the interrupter gear sequence it had to adhere to shooting thru the prop.
Anyway just a few of my toughts on the subject!