A Trap Grade 20 gauge is a nice gun. There were 348 20 ga. Trap guns made, 130 with 26" barrels. With a Hunter One Trigger, 122. I'm sure it must have ejectors and they made 284 of those. I would check to see what the constriction is as most shipped from the factory were full/full unless specified different.
Myself, I would not open up the chambers as there are plenty of 2 1/2" shells to choose from. This also decreases the amount of metal in an area where the pressure is the highest. If the gun is on the light side, the difference in weight came from striking the barrels.
