I guess I didn't type things up clear enough, no biggy.
Aiming is a Standard Action, in a sense without the Upgrade it's only beneficial if you wish to blow a limb off (important later on), so you cannot aim and attack on the 1st Round since you don't have the upgrade.
On the Surprise Round you attacked with an aimed shot that you could choose to be a critical or to take out a limb. I hope you're ok with me assuming you would prefer a critical hit. That means you dealt 38 damage with the first attack and 17 with the second, 55 total. Which is still pretty nice isn't it?
Bigfoot's attack is 26 & damage is 12
Note, you are in his threatened range if you use a Ranged Weapon to a Move action to move elsewhere you'll provoke an AoO.
Btw, if you lose a leg you're Speed is halved and if you cannot reach your intended target you simply go towards it s far as you can in the next update. If you lose an arm all Off-Hand attacks are subsequently ignored. I will only adjust these changes on the round it happens if the party
didn't win Initiative. Updating the House Rule thread with this information.