Stranger than fiction
 

The rifling runs the full length of the bore, and could not have been done without removing the barrel. I got this gun from Oscar Gaddys collection some time ago. Strange indeed, and when I asked about it, Julias said they had sold 2 of them.

have you ever shot this gun with slugs to see what kind of accuracy it has...charlie

Some 30 to 40 years back , I purchased a set of rifle barrel inserts that were 12 to 16 inches long that were marked PARKER . A collector friend wanted them more than me , so I sold them to him . I also owned an L C Smith and Lefever that had rifled barrels---since sold. I would say that the American shotgun makers of earlier days would more than likely produced guns with rifled barrels---but rare . Combo guns of Europe , etc. are common place.

If I remember correctly, there was a post on the old website of a Parker with one rifled barrel. The rifling was not cut into the bore, it looked more like it was formed with a button and you could see it on the outside of the barrels.

Doc Van 's rifled bore CHE
 

Photos of the gun. I'm sure we are not experts but some of the more significant Parker collectors looked at it and concluded that there was no evidence that the rifling was not factory work. We also exhibited it at a Pheasant Fest where 25,000 people could look at it.

The gun had been sent back more recently to have case colors added in a manner that the owner was informed by the gunsmith shop that this was the way Parker originally did them.

I have never fired the gun.

Has anyone thought or studied what the pressures would reach using a slug through these barrels...

I suspect Parker did.

Why would a one ounce ball generate a higher chamber pressure than a one ounce shot load where both are sealed by an over powder wad or shot cup. The issue is muzzle constriction isn't it ?

I would think the resistance to the slug making contact with the lands causing it to rotate would surely cause a rise in pressure and produce a lesser velocity than the same slug shot through a smoothbore.. agreed??