MCH Attack Error?

I just hit 45, trying to make my way to 50 to slip into Ironworks etc- I ended up buying a HQ Lv45 gun to last me to 50 and when I swapped out the old one it only added 2 attack, is this incorrect? I never noticed anything like this on my other jobs.

Here are some screenshots for comparison.

Old Gun
http://i.imgur.com/zCoTmhz.jpg


New Gun
http://i.imgur.com/9CDtU5s.jpg

Attack power = dexterity. New gun gave you 2 dex, so your attack power went up by 2?

I see, thanks for the clarity, I thought the attack of the gun would raise attack power instead.