R1 on 3B, R2 on 1B, with 2 outs. F4 fields a ground ball and tags R2 priort to reaching 2B. R1 scored prior to the tag. Does the run score since ti was not a force out 1B?

R2 is a force out. Dave

As shipwreck stated this is considered a force out. because of the batter becoming a batter-runner R2 was forced to advance to 2nd, since the third out was obtained prior to a runner that was forced to advance safely doing so no run can score. Think of the runners and their situation not whether it was a "force" out like standing on the base with the ball. The runner was forced to go, whether she was tagged or put out by a fielder on the base don't matter.