Tatume---

Daryl has done some excellent work with round ball loads. I suggest you read some of his many posts on the subject.

I really like double barrel slug guns so I am prejudice and will almost always say you should try slugs! hahaha

It sounds like a really nice gun and since it is yours and since you want to consider shooting slugs with it SO you CAN use it MORE, I don't see anything wrong with investigating this choice.

My own experience is you can shoot round balls effectively by sizing the RB smaller than the bores or the chokes and using a variety of materials as a "patch", or using a shotcup placed upside down in the hull with the concave bowl holding the round ball. Obviously, for a full choked tube, you should measure the actual diameter before doing anything(!) Theoretically the full choke will measure .694 diameter.

With that said, I would think you might be able to use a .690 round ball and as long as it is smaller than the actual numbers you get when you measure the chokes, then the shot cup will act as a carrier to center the slug in either barrel and it will shoot out of the IC and the full choke. I would start with off-the-shelf round balls because they are pure lead and softer to minimize potential of damage...

I recently cut the barrels on a side by side and then shot slugs from it. The left barrel hit consistently at point of aim (hurray!). The right barrel hit slightly left of point of aim. There may be a bure on the right barrel so after I do a light sanding job I intend to shoot it again and hopefully it is not the barrel itself being off... however even at that, as long as I know where the right barrel will hit at various distances I am good to hunt with this gun.

Obviously on your 1949 gun I would start with---and most likely stay---on the LOW powder side of any load formula. Low is about 10% under what the published load might be for a regular load recommendation. You don't want to go TOO low, either!

I would talk with guys who shoot slugs from smooth bores. That includes the gunsmith you should take this gun to to check it out thoroughly before you attempt shooting slugs through it. Not all gunsmiths are created equal...

I have found in my years of slug experimentation that shotgunners are divided into very different schools: (1)some are adamant that all shotguns are for best for shot only and are not really for slugs, (2)some would not recommend shooting slugs from doubles because doubles are not made for that, and then (3)there is the school who have shot slugs from doubles successfully--- They are always working on ways to shoot slugs from another side by side! (that's the school Daryl and I belong to! hahaha)

From 410 to 10 gauge doubles I think side by sides can be great slug shooters! It funny too---every guy I have talked with who has pulled an old double barrle out and tried shooting slugs with it has beenm amazed at the surprising accuracy. Theya lmost always say---it shot better than i thought or better than anyone told me it would.
I hunt white tail with a side by side 12 gauge... every hunter out there has said --- " Are you sure about that thing? It seems like the wrong gun to me."... hahahaha. The deer "this thing" has taken apparently haven't listened to the sage advise I've gotten! hahaha