That's good to hear from a fellow member here, Bonanza.
I just got an email from Woody at Lothar walther, saying he would make up a pair of similar liners for the next 12gauge cz I have on order.
These will be in .500 3". However I will only be using nitro-for-black loads.
He spoke in the email of adjustment rings? And o-rings?
Also, a bit of interesting info, is that, they have been making these for Kreighoff for more than 50yrs., and he said they were very popular in Europe. Hope I have not let the cat out of the bag with that info. However, I have yet to figure out how one can reliably regulate for a certain load with these, but then, I've not seen them in person yet. Given that these are "what they are", I was at first a little nervous about the thought, but from everything I have collected in the past three or so days, they seem to be a legitimate route to take. I mean, come on, Kreighoff? Thats a big name there, using liners like this. So, there must be something I've missed, or I must have been asleep that day in class, so to speak.