While you are on the site, in your browser find and click "Add to Home Screen" A CGN beaver app icon will then be created to your phone that is directly link to the site.
Note: This feature may not be available in some browsers.
I am in the other boat. I got took on a gun deal and ended up with a magnum action and a standard barrel. I have tried to find a magnum 20 gauge barrel for a couple of years now.
I don't know if there is a difference to the barrel or if you swapped the part shown a mag barrel could work on a standard version (or vice-versa). Issue will be if a non-magnum barrel is put on a magnum gun and a user puts in a 3" shell as receiver states magnum...... And the thread pattern on a magnum or standard part may be different , have to inquire with Browning?
Barrel would definitely need identification if this swap works.
From what I have gathered while scouring old forums, is that there is no real viable way to make it work.
Issues including:
Ejection port is too small.
Length of stroke on a 2¾ gun insufficient to handle 3" shells.
Barrel dimensions are different, the 3" barrel has it's magazine tube guide located further forward.
Insufficient friction rings.
It seems as though the OP had luck getting a 3" barrel to fit a 2¾" auto 5. But only chambered 2¾ shells. And was pretty convinced with some modifications (see: hacking up a vintage Belgian auto 5) he could fire 3" shells. But he never posted again and never followed up on his range trip, so I doubt it.