Kiwi, that's an interesting question and I'm sorry I don't have a definitive answer. The next question that comes to my mind would be is the firearm I am thinking of installing one in of strong enough construction to take the pressure of the proposed insert? If that answer is yes then as with just about anything, if you're willing to pay for it I expect it can be done.
They aren't commonly known on these shores either. I just fitted a Krieghoff einstecklauf in 22LR, (the 10 inch one), to one of my drillings and I am having a ball with it. It certainly draws some strange looks when I hand it to someone and they open the action and see the 3 chambers, all different.
