Thanks for the replies. They are all helpful.
Intended "use" was asked more than once. I am after accuracy, as measured in group size and score on a paper target in a short range, non-competition bench environment only. By "short range", I mean 100 yards, 300 once in a great while (range availability), and 1000 if I am somehow fortunate. The majority of experience, advice, recommendations, what wins, is mostly applicable to longer ranges in the cartridges I have. Who competes at 100 yards with a 223 at 100 yards (or even 300) much less with a 6mmBR or 6.5 x 47? Bullets for long range are not applicable for my use. If there is the question of why build such rifles for short range, I can speak to that separately.
I consulted
http://www.6mmbr.com/223Rem.html and have used some of the 52 - 55 grain Sierra and Berger bullets recommended there. Those have worked well at 100 yards. The 69 grain Sierra MatchKings did not, but who knew what the barrel would like.
Bullet availability is a concern for sure, and good advice to buy a lot when available. I am keeping any eye out for sales...my credit card is now endangered!
Seems like an earned reputation is a good thing to watch for, so will continue to explore that. The 6.5 x 47 I am building now and comments on bullets is pointing me to the 123 grain Scenar. Reasons for that include:
1) Surprisingly good ballistic performance, even at longer ranges (if I can ever get to shoot that far).
2) Earned positive reputation that seems to far outweigh negatives I have found.
3) Length makes for an easy fit into a magazine even as OAL lengthens while chasing the lands.
4) Lighter weight (vs 139 - 142) minimizes recoil.
5) Apparently, easy to load for (based on info I have read).
6) Ideal for the short freebore reamer my gunsmith has.
Not sure anything else should be considered.
Phil