Baikal guns are still made and imported into the US. Here's the location of the US importer.

European American Armory Corp.
3855 North U.S. Highway 1
Cocoa, Florida 32926

I would contact them and ask your question.

 

These guns do come as multi-barrel sets in Russia, and you can order an additional barrel (not from outside Russia, unfortunately). However, the factory insists the gun must be shipped to the factory for the barrel to be fitted. Therefore, they are not interchangeable. Besides, your .410 was made on an old-style non-magnum action, and the newer rifles are made on a magnum, beefed-up version of the action. So, it doesn't sound like a good idea to put a rifled barrel on it.

This said, in practice some barrels sometimes interchange. I believe, if you get two 18s, a good gunsmith could ensure that one of the actions fits two barrels. If you're certain you do want a two-barrel set, you could try to achieve this with two modern guns, and a person who has a proven skill in barrel fitting. This is a bit of a lottery in that, however, and I'm not certain it is possible, just think it might be.

 

Short answer,no.It would make more sense to simply carry both rifled slug cartridges,as well as shot loads,and just use your .410 as it is.This would still be quite versatile,and more satisfactory than trying to use a centerfire rifle barrel on a shotgun receiver.