Gun-pods in general and the UPK-23-250 in particular

I was messing about a bit in the 'Tentacle soup' Mi-8 campaign. And I was wondering, what is the actual ammo load-out on the UPK-23-250 pods? I can't seem to destroy even lightly/medium armored (self propelled) artillery untis with it. The amunition(count) is somewhat limited and we can not choose what kind of ammo-loadout. So it seems they are loaded with HE rounds only wich make a big bang on impact and does nothing against armored targets. I was expecting it to have a mixed load-out of HE and AP rounds wich should make easy work of M-109 howitzers and MLRS units.

I found the 12.7mm gatling much more effective against armored targets. This round is much much smaller and it seems a bit strange to me this one is more effective against those units. And it has way more ammunition then the UPK-23-250 pods.

Shouldn't we be able to choose the type of amunition ourselves? It is also possible on the A-10C and the MiG-21.

I just bought the Mi-8 module few days ago and I have not tried UPK-23-250 pods yet, but I use them in the Ka-50 and they are very powerful and pack quite a punch. I do not think they mix AP with HE since I do not see bullets bouncing from its impact on the ground, something I see when using AP ammo in the 2A42 cannon.