RE: Free float barrel
A lot of guns will shoot tighter groups with a fore-end pressure. Problem is that the group may not hit the same spot from day-to-day and week-to-week; due to the effect of temperature and humidity on the amount of pressure the stock exerts on the barrel at that point. The other issue is that a gun with fore-end pressure will usually shoot lower off of sand bags than it does from a Harris Bipod or a fence post. So you aren't really sure, in a specific situation, just where your gun is going to shoot.
First choice is a free floated barrel. If it is one of those black plastic stocked Remingtons, take out quite a bit of material - a gap the thickness of credit card would be about right.