When Briley first started installing their Thinwall choke tubes, they experienced a few problems with them in Superposeds, which was based on barrel thickness at the muzzles and the fact that some older and a few later Supers had barrels with a "flat spot" between them at the muzzles that caused some installations to go awry. I had a 1984 Super they did and it turned out fine, but the tubes were very thin and you had to be careful with them to prevent damage.
After some real f*ck-ups, they soon learned how to judge which ones could be tubed and which ones they would not do. It's my understanding they now have the process down and judge each gun as a "go" or "no-go" and are having no further problems.
JR
