Hi there,
I ran the first part of the Frontier War campaign some time ago, and as I'm considering picking it up again, I'm taking another hard look at the rules, especially those for vehicle armor.
I hardly ever use house rules, but to me, the way armor on vehicles is represented in the rules is way off the mark if you want it to be somewhat realistic.
The way armor works now, characters with handguns can actually take apart heavy battle tanks if they shoot them enough. Realistically, modern battle tanks are practically impervious to anything but heavy armor-piercing weapons, and in a military-oriented campaign such as this, I feel that should be better reflected. It doesn't matter how much you shoot them if you only have a pistol or a rifle. The best you can hope for is to take out a headlight.
The solution I might try in our game is to have anything with hull points (not starships, as those are on a completely different scale) have each point of Armor automatically reduce damage. Armor is still halved for armor-piercing attacks. This makes such vehicles a lot tougher and more dangerous, forcing characters to use heavier weapons such as RPGs, cannons and other vehicles. It also allow for really good shooters to damage heavier vehicles, representing those weak points and such.
What are your experiences with using armored vehicles in the game? I had the players face some in Destroyer of Worlds, and they were easily picked apart by pulse rifles and smartguns.