You tear it down, clean, and re-grease it before shooting? Sticky actions on a new gun are usually due to not being cleaned and re-greased. Don't assume it's ready to go out of the box.

Also, it sounds like it was a problem with the scope mounting. 2-2.5 inch groups at 100 yards is not that bad unless you had it viced. Even rested on bags, you're gonna affect the shot more than you think.