Rossi Rifleman

I've got a ranger point precision foregrip installed, and I feel like the tenon holds the mag tube in place pretty good. Can I forgo the reinstall of the front barrel band?

From a standpoint of having the magazine tube SECURELY ATTACHED to the barrel/firearm, I would not leave off any parts in attachment. Spring tension of a full mag tube plus repeated recoil pulse may leave you with an unfortunate result. Especially if you are in the field without the proper tools for repair. Or on a firing range so as to avoid that "red faced" moment you have to explain to the RSO, "I reassembled it, but decided to leave off a part."

you can leave it off,, if you modify the rifle so that the screw that holds the mag spring in place goes through the tube and screws into a dovetail cut into the bottom of the barrel, or is blind tapped.