4 Bore Single Shot Action

[missionary5155]

Greetings
Bought 3 of the 4 bore brass casings that were offered for sale. Now need a single shot to use them loaded with BP.
It may more be cost effective just to have one built. So the thought crossed my mind wondering if there is an existing action already out there large enough to have a 4 bore barrel screwed on it. Would be a smooth bore.
I have read a rolling block was used but I cannot verify that notation. If so I have several that I would happily rebarrel.

I do know the brass has a 1.038 outside diameter. Rim diameter I would assume is going to be at least 1.060 or so. Length is 4 inches.
So my question is... What is the outside diameter of a #1 Roller ?
If you have any other make of single action what is the outside diameter ?
I would think an action is going to need to be a minimum of 1.5 inches wide. The wider the better.
In my reading most of the old single 4 Bores were about 17 pounds with 24 inch barrels.
So if you can measure any action easy to get to I would appreciate it. This is not a time wise emergency. I have until June 2020 to get this figured out.
Thank you ! Mike in Peru

[Huvius]

I do think that for a four bore, you will be making an action.
There may be some whaling guns that could serve but they are rare and expensive in their own right.

[samari46]

Try looking on the nitroexpress.com forum a lot of the members play around with the big bores. Frank

[NoZombies]

Do you care how historic it looks?

The VZ-85 26.5mm might be an answer for you if you aren't after the historic look.

[missionary5155]

Thank you ! I will look at that site and the VZ rifle.

[Boz330]

Maybe a Greener Martini action or possibly regular Martini Henry action.

Bob

[lar45]

There is the Russian Tula 4 gauge shotgun. You might also look into a Punt Gun, I'm not sure if they were all muzzle loaders, or if some were breach loaders.
4 more brass can be made by turning the base down on 20mm Vulcan brass. I made a couple for my WW1 German flare gun.

[missionary5155]

Howdy Lar45
Thank you for that info. I will look into that Tula 4 gauge.

[Nobade]

Give a call to Stolzer and sons Gunsmithing. He has built several. Probably be able to find him on YouTube also.