RE: Firing into an Hex
Sorry it has taken longer than usual to get an answer. Often you'll get a response within a couple of hours. But I think everyone's been busy with the holidays (and the new SB release!). I have provided some extra detail below, but the simple answer to your question is yes, the computer selects only the armoured targets.
The following is a relevant excerpt from the Users Manual:
Based on their characteristics, certain weapon loads have restrictions as to the types of targets they are effective against.
• Ground Only – these loads have no affect against flying Helicopters. These represent loads such as those fired by tanks or artillery that have basically no chance of hitting a flying target.
• Vehicle Only – these loads only affect Vehicle targets and Infantry targets in Bunkers and Pillboxes. Also Infantry targets in Caves owned by the same side as the target are affected. These loads represent armor piercing loads that have no explosive ability of their own and thus have no effect against infantry targets in the open. This restriction includes the Ground Only restriction.
While you are allowed to fire against any target using these loads, they will not have any effect on restricted targets. The loads with these limitations are flagged as such in the Weapon Data Dialog available from the Help Menu.
My understanding is that AT rounds will not affect infantry unless the infantry units are in a bunker, pill box, or cave. And if someone happened to leave their tank parked in the bunker and were standing next to it, both they and their tank would be affected by AT rounds.
I might make two additional notes:
1.) Infantry units in the same hex as a vehicle (but not riding the vehicle) actually gain a small degree of protection from being in the hex with the vehicle. (Just take care if your vehicle is lightly armored that you aren't attracting fire to that hex by stacking units together, thereby making an attractive target.)
2.) Infantry can be affected by AT rounds if they are riding the vehicle, not so much by the AT round itself, but the effect it has on the vehicle (see the following excerpt from the Users Manual).
Certain limitations and effects occur when a vehicle has external riders:
• A vehicle with external riders cannot fire nor can the passengers fire.
• A vehicle with external riders cannot attack in assault.
• When a vehicle with external riders is fired upon, the riders are automatically unloaded, become Disrupted, and may take losses.
• When a vehicle with external riders is assaulted, the riders are eliminated.