[B-Matt]

Use simple code for adjusting health and armour with damage.

Код:

Damage(playerid, Float:health, Float:armour, Float:damage)
{
	armour -= damage; //Will decrease
	if(armour <= 0.0) //if armour is lower or equal to 0.0 do..
	{
		armour = 0.0;
		health -= damage;
		if(health <= 0.0) health = 0.0;
	}
	SetPlayerHealth(playerid, health);
	SetPlayerArmour(playerid, armour);
}

Use in OnPlayerShootPlayer:

Код:

public OnPlayerShootPlayer(Shooter,Target,Float:HealthLost,Float:ArmourLost)
{
        switch(GetPlayerWeapon(Shooter)) //Switchs shooters weaponid
        {
       		 case 34: {
			HealthAdjust(Target, HealthLost, ArmourLost, 35.0); } //Default weapon damage + your custom damage
	}

Code above is only for health damage and won't work if player have armour.