Shielded Mage feat and AC when casting.

[Jesper Roland Sørensen]

I have a quick question for the rules regarding the shielded mage feat when using the shield hand to cast a spell.

Quote:

Prerequisite(s): Shield Focus, base attack bonus +3 or fighter level 1st.

Benefit(s): You reduce the arcane spell failure of any shield you use by 15% (to a minimum of 0%). Using a shield does not prevent you from completing somatic spell components with the hand wielding the shield.

Would I loose the shields AC bonus when casting a spell with that hand? I can't find any kind of rules about this in the core rulebook, I'm looking to build an armored battlemage and would love to go sword and board with him.

Thanks in advance for the answers.

[SlimGauge]

The rules you seek are from the Buckler

Buckler wrote:

In any case, if you use a weapon in your off hand, you lose the buckler’s Armor Class bonus until your next turn. You can cast a spell with somatic components using your shield arm, but you lose the buckler’s Armor Class bonus until your next turn.

So without Shielded Mage, you CAN cast a spell with somatic components using your buckler hand, but you lose the buckler's shield bonus.

Without Shielded Mage, you can't cast a spell with somatic components using your shield hand while you've got a light shield equipped, but you can carry an item.

Without Shielded Mage, you can't use your shield hand for anything if you've equipped a heavy shield.

Shield Focus (the prerequisite for Shielded Mage) says nothing about it.

Going by "a feat does what it says it does (only)", then we've got the weird strict RAW situation where you lose your shield bonus to AC when casting with a bucker, but not with a light or heavy shield when casting via Shielded Mage.

[Jesper Roland Sørensen]

Thanks for the answer I had come to a similar conclusion like that, but wanted to at least have it said by another also.
Since it's for PFS I plan to make this I can use the RAW interpertation you gave.