Chin Sol close range dmg?

How close is the close range?
I tried being just next to the mob and I did the same dmg as from far away.

I have some good constant lag though.
When I have the Molten Shell on me and it explodes I see how the explosions happens on different place, 5-6 feet away from my current position - so that might be the reason for me not getting in the close enough range to the mobs with the bow so I see the difference.