FWIW, I just threaded 2, 455 Varmint barrels. One 22LR, the other a 22WMR. Both barrels measured ~.860" at the the muzzle. Threaded 1/2-28, that leaves a pretty good shoulder for any suppressor to butt up to.
I never thought I'd grow up to be a grumpy old man, but I did, and I'm killin' it.
