S! Cobra
"Effective range"
Hmmmm.... Now there's an open ended question.
What exactly do you mean by that? Do you really understand what you are asking? I don't think so.
"Effective range" is a completely fluid concept. It varies, depending on a huge number of factors, some of which can include:
1) Is the target moving?
2) Is the targer moving towards you? Or away? Or at an angle? What type of angle?
3) What speed is the target moving at?
4) What angle is the projectile striking the object's surface?
5) What type of object is being struck? What type of armour protection does the target have? Is a sheet of 50mm armoured glass? Is it a sheet of 5mm Aluminum? Is it a 10mm sheet of hardened steel?
5) What type of round is being used? Is it Armour piercing? Armour piercing Inciendary? High Explosive?
If a finite set of parameters is set up, with all tests done to that standard, then it is theoretically possible to establish a reference point for comparing various types of weapons and ammunition loads. However, to use those results, and define them as the perfect answer to what is "Effective Range" is a fallacy.
For that type of data, I would refer you to the sites set up by Mr Tony Williams, or the books he has written.
http://www.delphi.com/n/main.asp?webtag=autogun&nav=messages Other data may be found in the records of the Luftwaffe, RAF, USAAF and other combatants of the period.
For a look at the type of manuals issued to the pilots of the era go to:
http://www.simhq.com/simhq3/sims/air_combat/RAFgun/ You will note that nowhere in this manual are ranges over 600 yrds even listed.