Rules: Armor Piercing Ammo

One of the benefits of being a House Davion unit is that you get to play with their toys first.

Ordinance Sgt. Juan Manillo

Our Ordinance Sgt. Juan Manillo, got us a shipment of Armor piercing AC10, AC5 and AC2 ammo. 
It is only usable with Regular AC's, not LB's or Ultra's.  So only Pillsbury and Patriot have mechs that can take advantage of it at this time.

Here's how it will work.
Every attack with armor-piercing ammunition that successfully damages armor provides a chance for a critical hit, even if the internal structure took no damage. After marking off the armor damage for the attack, roll once on the Determining Critical Hits Table.

Apply a modifier to the target number based on the type
of autocannon used:
–1 for an AC/20
–2 for an AC/10 (Need a 10+ for one crit or a 12 for two crits)
–3 for an AC/5
–4 for an AC/2 (Need a 12 for 1 crit)

If the initial attack damages the internal structure, make the standard roll for possible critical hits. Armor piercing ammunition has no additional effect for attacks that damage internal structure.  Likewise a floating crit roll will offer no additional bonus, just treat it like a regular floating critical hit.
The weight of armor-piercing ammunition means that a ton of armor-piercing ammo contains half as many shots as a ton of standard ammo (rounded down).
In addition, armor-piercing rounds are harder to aim, adding a +1 modifier to the to-hit number at all ranges

Vehicles: Every successful attack against a vehicle automatically causes a roll on the appropriate column of the Vehicle Critical Hits Table

So before the next battle starts Those players with regular AC's will have the option of loading up with AP ammo if they want.