A little land vehicle help

[LethalBanana]

Hey guys so I'm new to this place and I'm in a little trouble.

So I successfully put the bmp-1 from pr to vanilla bf2 along with the needed stuff. I noticed while I was playing that whenever I shoot the tank with for example a pistol, the tank takes heavy damage. I tried increasing the armor but still getting damage by handheld wapons. can anyone help? I'm only experiment with how pr vehicles work in vbf2.

sorry for my english guys I'm from belgium