You won't be able to find an A1 back(pretty sure they didn't exist), but you will be able to find a G7 fly threaded back. Same threading, just a longer shank. Throw a beauty ring on it, or leave it be.
does anybody have any feedback on the freak-bored A1 backs? somebody else doing freak-boring is saying the A1 backs are too thin to do.
I got that same info from the same guy that freak bored my DYE ULs but as mentioned above - stanchy can do them. I have an A1 barrel freak bored but don't know who did it. Probably stanchy. LOL
Stanchy has done several A1 backs. Obviously you want to use the largest bore back for the donor (sticking your .691 insert into a back that was originally .689, for example, obviously defeats the purpose since the A1 back is longer than the Freak insert - you'll be stepping down bores from the insert to the barrel). I've heard nothing but good reviews from the people who've had theirs done.