Re: Trg 22 5/8-24 thread adapter
I don't mean to avoid answering the OPs question, but I think one should consider the decision to put an adapter very carefully. The OP mentioned having good dope as a reason not to re-thread the barrel but it may turn out that the thread adapter causes a change. Also it is introducing another layer of tolerances which may adversely affect the precision rifle. it MAY be the most painless course is actually rethreading....
Again, sorry I did not answer the OP but I thought it was a relevant point given some of the info listed in the posts. Just my .02
I decided against a thread adapter with my 18x1 rifle