Thanks guys. Can I use the same mag box and follower if I go with an ADL stock?

Use the mag box from the BDL as it will fit the floorplate correctly. Most of the 721 boxes willbut I rand into one that didnt want to fir the floorplate. You may have to file a notch out some at the upper rear of the mag box depending on the configuration of the box itself some have slight differences and may have to file off the tab that the little mag box screw goes through on the BDL style as the old 721 mag box didnt have it. You may also have to file the upper front of the box to make it match the feed opening where the shell slides foreward out of the mag into the chamber.

I just recently have come into a 721. I have a couple questions about it.

First are the threads the same on the action as on a 700, i.e. will a take off barrel from a 700 screw onto a 721.

Second will a drop in or take off stock for a 700 fit the 721?

Thanks in advance...