FX impact owners

"GQ"Tominco

What do you mean with center slot ? Of front slot ?
If you look at a pic of the Impact, the picatinny rail on the bottom has 3 slots. You want to center the Atlas by using the center slot. 
If you use the front slot, you'll be too far forward and hit the bottle with the Atlas clamp system which will scratch (or worse) gouge the bottle.
Tom