For a 6br you would need a standard bolt head, the problems with the 6br on a Savage action, are first with the short case they sometimes have ejection problems. This can be fixed, and there is several ways to skin the cat. For the most extreme 6br extraction problems SSS makes a special bolt head for them, with a different extractor. The other problem is there is a small section of the action that may need to be ground out, (with a dremel) or it will cut slots on the shoulder of the brass. (My 12 benchrest did had this problem.)

I am not sure, but I believe that all the ports are the same size on the target accu-trigger actions regardless of them being rblp, rbrp, or dual port. As mentioned before the pre-target accu-trigger rblp guns have small ports, and I think they are the only ones. Many complained that it you had an ejection problem you can not get your finger into the ports.