Experiment

[Gerald McPherson]

http://www.gunbroker.com/item/706704858
Check this out. Lesson learned.

[Mills]

If that guy is still around to benefit from the lesson and is in one piece, he is lucky

[Opening Day]

Good parts gun !

[MarketHunter]

What's funny is several companies sold chambers to shoot rifle and pistol cartridges out of shotguns.

[Mike Poindexter]

Current SAAMI spec for 44mag is 36,000 psi. While the chamber insert probably holds the wall pressure, the pressure against the breech face and firing pin hole would seem to be unaffected, so the little gun is eating way more than our 7000 psi vintage shotgun shells, or even the 11000 psi SAAMI spec. Were the old chamber inserts designed for lower pressure black powder rifle cartridges?

[Mills]

Very interesting Mike.

Glad to learn that the easy way

[Researcher]

Remington Arms Co. offered these for a number of years --

Auxiliary Rifle Barrel 1901 Catalogue.jpg

1901 Remington Arms Co. catalog.

Note the warning about "high pressure smokeless powder cartridges"

[Kensal Rise]

Originally Posted by Mike Poindexter

Were the old chamber inserts designed for lower pressure black powder rifle cartridges?

In a word, yes. But one must remember that gas seal and firing pin clearance are the critical culprits here. Inserts do not offer an effective seal against gas flowing backward. And firing pin/standing breach clearance in these old doubles is generous. Result:
High pressure gas flows backward and around the insert, into the firing pin hole and lock recess, then blows out a chunk of 100-year-old black walnut.

Oops.

[MarketHunter]

I'm not saying I'd use one, but I believe Marbles sold them into the 50's or even after.

[Bill Murphy]

All of my Marbles inserts are "rifle to rifle" made for guns with small firing pin holes.