I bought one from Germany - the german seller / gunshop / manufacturer simply gets an export permit and sends it. Not sure what happens in the US, but here in the UK I had it sent to a friendly gun dealer.
I used
http://www.zimmermann-waffen.info and with the aid of Google Translate we worked it out. Mine shoots very well.
Do note though, there is an element of work required at your end to fit it to your gun.
1) The rim is supplied over size and this needs turning down to fit the rim in your gun to get correct headspace. There is also a brass adjustable collar that needs adjusting to the forcing cone - this is on a screw thread and takes five minutes to get in correct.
2) The muzzle sleeve is also oversize and needs turning down to fit the choke.
3) Finally a small slot needs cutting into the extractor and a retaining screw fitted - this may some sucking of teeth!!
I got mine in 7x65R to match the existing 7x65R barrel so I have a double rifle (its a combination gun) for shooting running boar. For me a 22 Hornet or other small centrefire is probably not that useful - any fox will fall over just as dead. I could use slugs for driven boar on the continent, but my biggest challenge is getting licence permission to hold them in the UK and indeed even getting 16 guage slugs in the UK. Don't really fancy trying to shoot big boar with untested and unzeroed slugs.
As a double I can put tow rounds from each barrel into a 1" group at 50 yds.
