Maybe I am just behind the power curve on this one but if you have a rifle that has not been shot, why did you want to take the barrel off?
Let me give you one more reason for pulling the barrel on a 10/22. There was an episode on one of the TV shooting shows (there's a copy on Youtube) about a gun shop that specializes in accurizing 10/22s. According to them, the difference between a 10/22 that shoots 1-hole at 50 yds and one that doesn't group nearly as well can usually be attributed to only 2 different causes.
1. Bad crown
2. Too much bullet jump (distance from bullet tip to the start of rifling). Apparantly, 10/22s don't like to jump at all.
When they accurize a 10/22, they set back the barrel so that the bullet is almost kissing the rifling.