yes it will fit and work just fine

Good evening to you!! The Black River 12 Gauge 20 Round Drum Magazine, will fit and function just fine in your VR80 . The VR80 accepts M1919 platform magazines. Hope this helps. Have a good rest of your day.
🇺🇸🇺🇸 'merica' 🇺🇸🇺🇸

Shane, this magazine will fit in a vr80, but with any semi-automatic shotgun, it’s usually a good idea to run high brass ammo though it to make sure it cycles properly, at least until it is broken in.

Hi Shane and welcome. Yes, this is a 1919 pattern drum and will fit the Rock Island Armory VR80 no issue. It is easier to load and more reliable than the Promag Drum. Cheers, stay safe and enjoy!

Hi Shane, yes sir, the VR80 accepts 1919 style magazines.
Stay safe & have a great day!