The bullet can get marked as it feeds from the mag to the chamber and be scored as if engaging riflings. Paint a bullet with a sharpie then hold the rifle downward and drop a loaded OAL 2.20" round into the chamber then close the bolt and slowly eject the round and look for rifling marks concentrically on the bullet. If you see the 4 or 5 scores evenly spaced around the bullet then I guess you have a real short throat. The only 2.20" OAL rounds I use are the Speer 70gr semi roundnose bullets that have a lot of forward swell. The V-maxes are pretty sharp and long tapered.
The marks you get from chambering do not resemble rifling marks.
