If it has removable chokes, take the choke tube out of the muzzle to make sure it's not seized. If it's a fixed choke, inspect the barrel for any cracking. Then check normal functioning and operation. Get a couple full-size snap caps and run them through the gun to make sure everything functions okay.
DinanTronics Stage 1 F30 328i M Sport
Dinan 20" Black Performance Wheels
Gunfighter Training Development and Evaluation
AR15/AR10 Armorer/Advanced Armorer
Gunfighter Training YouTube Channel