One of the truly "interesting" things about OOB work is the sheer number of sources that conflict. It's bad enough for more modern weapons where one might assume actual capabilities are classified but it can be more than just a bit frustrating when dealing with 70 year old weapons with capabilities that should be well known.
For example. This website
http://www.tarrif.net/
when you click on the British section/ Artillery has this to say about the 2 pounders capabilities
Penetration Data for the 40mm Q.F. 2 Pounder Mk.IXA L / 50
AP Shot Mk.I ( Armor Piercing )
100 m--66 / 49 mm
500 m--50 / 38 mm
1000 m--35 / 28 mm
1500 m--25 / 21 mm
2000 m--18 / 16 mm
so 66 would translate to a 7 pen and as there is data out to 2000 metres one might assume the range was also greater than 600 yards. Yes ?
The AP model we use in the game gives that gun a 7 pen out to 250 yards when it drops to 6. at 500 it drops to 5, 600 drops to 4, at 1000 it drops to 3 and at 1450 it drops to 2 and at 1950 it drops to 1 and I have no problem with any of that.
So if we look at what the game does with this gun at the range stated in the Chris Bishop book "the 2 pounder penetrates 53mm at 455m " this fit's in quite nicely with the 5cm of penetration that game gives that gun at 500 yards. There is absolutly nothing wrong with the penetration or range numbers we give that gun in the OOB's
However, it's a safe bet if you dig deep enough you can find a half dozen different answers to the same question. Wikipedia, for example, gives a maximum range for the 2 pounder at 1000 yards but penetration data out to 1,371 metres ( 1500 yards).
A bit of a conflict of information but typical of what can be found on the net and in text
Don