ID of H&R Single-Shot Shotgun from Barrel

[M100C]

Hey All,
Looking for an expert in H&R single-shot shotguns.

My father-in-law recently found the barrel to his favorite shotgun. He bought the gun in 1942 from his uncle, and the rest of the gun (receiver, stock and forearm) are missing.

I see H&R made many models up until 1942 (he is not sure how old the gun was when he got it), so I am not sure if it is possible to tell model and year from the posted pictures, but I thought I’d try.

Truth is, I could probably get a shotgun, and fit his barrel cheaper than trying to source the parts. He just celebrated his 90th birthday, so I am committed to getting this barrel in a receiver/stock/forearm combination for him. Thanks for any help/advice you can provide.

 

[M100C]

Sorry All,
Posted this to the wrong forum, and I cannot figure out how to move it. If someone would enlighten me, I will move it.

 

[22250Rem]

I'm not up on old H&R's but was just at a gun show yesterday and saw two of 'em for sale on two different tables. Both were 12 ga. but I wasn't looking for anything like that so I didn't pay much attention to them. But they're not all that uncommon and they turn up for sale now and then. Chances are you could pick one up that could be from the same era ( don't know what, or if, there were any design changes during the production life of those things) and possibly put you barrel right on and have a gunsmith who knows shotguns give it a check-up. If you find a used one for sale maybe the seller would let you try your barrel on it to see if it was compatible. If it was then your father-in-law could have a shotgun with a spare barrel. Numrich Gun Parts also has some listings for the old H&R Topper single barrel shotguns if that's what yours is. Wonder what happened to the rest of the gun? Could the receiver, stock and forearm be in an attic, basement, closet, etc? I used to know a guy who had found old guns and/or old gun parts hidden away in rental properties that he purchased. Stuff sometimes gets put away and eventually forgotten.