I'm looking to find out what barrels interchange between 2hat shotguns.
220, 219, 94, etc. Do any of the barrels differ from one another?
I know some are snap on, some screw on forearms.
As long as the forearm matter as long as it fits the barrel.

Anyone?
I'm trying to find bargains to build a set.

I think there are others more familiar with these than I am, but I have swapped barrels on the three I have, a couple 220's and a Stevens 94, they all fit the actions but there is some difference in the amount of engagement in the latches, so there might be some fitting needed for that. I also tried a Model 24 22 over 410 barrel on a 220 receiver, it fit but the latch would not engage.... so I slammed it shut and then the latch would not disengage... I will not be doing that again. It looked like it had a very long tube sight.

FYI found some information here Savage Single Shots and trying to learn more.

It sounds like the answer to your question is: It depends. Vintage more so than anything because the cocking action is different between era of manufacture. Early versions cock with the top lever, later ones cock with the barrel opening.

Now I'm going down the road to find a rifle barrel that will swap with my 220.

LHS

This book is worth having on your bench, and a call to the author, who was still actively pursuing questions and answers about these rifles a couple years ago.

Savage single shot rifles

The author, Garnett Stancil Jr., is the owner/operator of the website I posted the link to. He has several other books posted there. He has been very helpful in my inquiries.

LHS

Just don't mention that you have a .32-20 WCF 219 barrel if you do He'll WANT it!

Garnett is a very nice man.

He knows i have a 32-20!! he also knows about my savage 101 for dummys, and he is a pretty decent guy!