One thing of great importance in using an "Unguided" adjustable reamer from the muzzle is whether or not the original choke is a conical parallel or taper choke.
"NOBODY" can guarantee to maintain alingment with an unguided reamer in a taper choke. If you have the parallel section & take the light cuts you should it will tend to "Follow the Hole". Try it on a taper choke & you best for sure know how to use it to correct POI. Take this for what it's worth from a 35yr machinist.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra