Is it threaded inside or does it just slide over?
I've got a del-ton barrel and have tried a silencerco spacer so a tbac 22 suppressor can be used with a 22 conversion kit. The silencerco spacer can't be threaded up against the shoulder because the threads stop and it leaves about 1/16" gap. I've been having an issue with it throwing shots and a shim was recommended in the Silencer section of this site.
I saw it's measured at .25", which would leave only .35" for the suppressor to thread on. I didn't see anything else on your site but figured I'd ask if you had anything on there that would work.
I hope I'm explaining it well enough. I'm pretty much looking for a non threaded spacer so I can make sure it makes contact with the barrel shoulder.