Over aggro with small pair???

[hansarnic]

21 left, 10 pay. I have T8k (average), 7 on my table.

CO has open-raised pretty frequently over the last few orbits. No-on has come over the top. he has 20k. Blinds 400/800. I am button with 77, he makes it 2400. Both blinds have about 8k too.

I move all-in.

Q1. Was this over aggro?
Q2. If you are CO what range of hands do you put me on & what do you need to call?

Thx