[narwan]

Hi MarkSheppard,

it's not an invalid question, don't worry about that. But it does look you may have had two units mixed up. The 20mm Flak 38 (weapon 147 in Mobhack) has a HEK of 11, not 12. Perhaps you are looking at the 20mm Kwk38 (weapon 008)?
When comparing stats of weapons it is useful to check Mobhack for weapon types; the Flak38 is class 4 (Flak) while the MG-151 is class 11 (aircraft weapon). Often certain discrepancies between stats can be attributed to how the game treats different classes. Aircraft weapons for example can only have HE ammunition (goes back to the original code afaik) so AP capability gets translated into it. That means certain aircraft guns will be assumed to be firing a mix of shell types, in other words they'll be firing less HE shells than their max ROF fire would allow for so they'll get a lower HEK then you might expect.

Having said that, I'm no expert on the weapons in question so I don't know if the MG-151 fired AP rounds but the gun does get a HE penetration of 2 where 1 is standard for HE rounds for this calibre (see flak 38 and Kwk38 for example) so it does look like it is assumed to be firing some AP rounds.

Narwan

PS when posting questions about certain weapons in the game it makes things easier to check if you refer to its Mobhack number.