[Lordzy]

Try this

pawn Код:

public OnPlayerTakeDamage(playerid, issuerid, Float: amount, weaponid)
{
   if(GetPlayerArmour(playerid)<1)
   {
    new Float:ARM;
    GetPlayerArmour(playerid, ARM);
    if(weaponid == 24) SetPlayerArmour(playerid, ARM-40);//DesertEagle
   }
   else
   {
    new Float:HP
    GetPlayerHealth(playerid,HP);
    if(weaponid == 24) SetPlayerHealth(playerid, HP-40);//DesertEagle
    }
    return 1;
}
//Like that use for other also.

Sorry if there's a mistake because I didnt test/compile this.