Can anyone here please tell me if they know the penetration value of the 15mm besa mg, its been driving me crazy for over 10 years and i cant find it anywhere (bar the stupid made up facts of certain publications i.e. 57mm@300metres) And if you could tell me the source of this fact, i would be forever grateful, i really am interested in the combat usefullness of humbers and vickers, especially against weak Italian armor or vs gun shields and against other recon units.
Some meaningful figures are given in Tom Jentz’s book “Tank combat in N.A”.
Unfortunately, my copy is out on loan at the moment.
Perhaps someone else would look them up for you.
Try here - it’s the forum for Tony Williams’ website. He’s an occasional contributor here, and probably the biggest expert out there on this sort of thing. Alternatively his email address can be found here.
i shall look it up, thank you very much for your help, i cant wait to find out what it is 
you may find the info you seek in his book Rapid Fire,there are copies available on Amazon.A fine book, and worth the price.
Guns vs Armor lists 16 mm at 91 meters and 15 mm at 457 meters.
thankyou all 