My 50 yd 5-shot avg group is right at 0.30" c-t-c. I've repeated this group at least a half dozen times. With Eley Tenex. Occasionally larger, occasionally smaller, but I would say the 0.30" c-t-c group is repeatable when I do my part.
The action is for a straight shank barrel with no threads. I'm OK with glue in, unless it can somehow be modified with threads.
Righto.
So I'd call Mark Penrod in Manchester, IN to see if he'd be interested. Don't jump in on a bunch of details about F-class and whatever it is you know... just ask him, and let him lead the conversation. He's one of the "knowers" in the industry, I assure you.
Being a repeater, you will of course want a chamber that will extract loaded ammunition, so make sure to discuss that with him. I would assume that he has several reamers.
Personally, I would not go with anything NEAR as loose as a Bentz because this is an accuracy-minded bolt action that can be manually extracted...not a blowback that can only rely on extractor tension to get it done.
On the flip side of that, you DO probably want to use a reamer that has at last a small amount of taper. Judging from your posts and photos, and simply the choice of action and rifle, you are not the type of BR50 shooter that is going to maintain a spotless (and I MEAN spotless) dust-free chamber.
It TAKES that kind of maintenance to assure that a zero-taper chamber like a Calfee 1 will work out okay.
So stick to one with a little (0.0005"-0.001") taper, keep the freebore to the MODERATE end of things, and go reasonably tight on the "freebore" dimension to match that Eley. (NOT super short, and NOT super tight, or it won't extract without dumping powder all over your action).
Glue-in is totally bueno, provided it is a tight fit, and preferably, that the barrel's glue is allowed to cure in a vertical position.
It seems that the action could also be threaded 3/4-16 or whatever. Either way, with this much work, probably good to face the action.
It will take a barrel shoulder of about 0.900, if I recall correctly, but I don't personally think you need it, PARTICULARLY if you aren't threading.
-Nate