Do these things actually work? They say that their KS insert barrels can be used in the Quadro drilling to make a shotgun barrel into a rifle barrel, in cartridges all the way up to 9.3x74R. Has anyone used this piece of hardware? Do they stay regulated?

Is it just a Krieghoff thing, or are these kinds of barrels available for other shotguns as well? I'm sure that pressure would have to be low on any frame not designed for rifle cartridges, but could one use other low-pressure chamberings like the 9.3x74R in other guns? Is is possible to pick up a 20ga side by side and add insert barrels to create a double rifle? Their inserts are adjustable to provide regulation, so all one would need is a set of rifle sights on the rib and some extractor work - providing everything goes together properly and safely.

Why isn't this more commonly done, if in fact it is a valid way of converting a SxS shotgun to a rifle? Krieghoff page

I don't see anywhere it says these are for sale, only that they will be fitted to the barrel of their drilling. Somewhere else, they say the drillings are built on double rifle derived actions. I suspect they may not sell them separately due to liability. They should be easier to duplicate than a full double rifle conversion of a shotgun would be.

Right. I know their specific barrels aren't for sale separately, and I understand why. I'm wondering if one could get a similar barrel insert made of the correct shape, fit it to a shotgun set and solder it in once it's all regulated. Like Art says, it would be easier to do this than a 'proper' conversion of a shotgun to a double rifle - if such a conversion is/was ever really 'proper'. Just thinking out of the box, as it were.

I was actually just thinking about this today is the reason I posted. It should be easy to machine the muzzle end of one or both of the inserts to have three tapered slides, sort of like a gib adjuster in a lathe. These could be run in and out with socket screws from the front. Tightening all three would lock the insert in. Alternately tightening and loosening would adjust regulation in a tripod method.

The biggest limitation would be chamber wall thickness. Given the pressure of a large bore and good steel, I calculate you would need roughly 1/4" walls to have a safety factor at all. In a 20 gauge chamber, I don't know if this is possible after machining the breech for extractors. Using a 12 gauge would not give as pleasing a product.

I've thought about the chamber walls as well. There'd be no good way to do it with anything like a 470 sized case, so I was limiting my thoughts to the 9.3x74R cartridge (or 30-40 Krag or 303 Brit...they all have about the same head/rim size). The base is small enough to possibly work out, if one can assume that the original shotgun barrel and the insert would be soldered together at the breech, so that the shotgun barrel would effectively add its thickness to the insert's wall thickness. Heck, I'm not even sure that would fly, but it's been on my brain for the last few days...

The 12 ga would be ok at the breech, but way too large for the rest of the way. Definitely not attractive. What about a 16 ga with full chokes to put a decent taper to the muzzles? Are they even available in new SxS guns? I wouldn't want to butcher up an original. Thanks for the input Art.

To all -
Try this link for another source of the insert barrels - MCA Sports/Chamber Adapters
They make inserts for 20,16, and 12 gauge shotguns in a variety of mostly low pressure cases.
Ken