GSRswampandslow -
Basically you could chamber about any caliber, that is in a capable LR-BR platform (stock, action, barrel, rests), develop consistent "aggregate" capable handloads from high coefficient & quality bullets, and you could compete well and no doubt win at 600/1000-BR matches.
If you go to the 600/1000-BR websites and study the results & equipment lists from several ranges (not just one) you will see the trends of what calibers are winning and consistently doing well. This is where many calibers that are more then capable of LR accuracy and great ballistic capability, you can see are "one hit wonders" in Benchrest, because they lack the efficiency, consistency, and aggregate capability that other calibers have. You will see they may win now and then, and do well here & there under certain conditions, but on a whole they do not repeat day in - day out - match to match, as well as other calibers.
If you go back in time, and study the results from say a 10-year time span and from several different ranges, you will see there are calibers that were "hot stuff" at one time, are now struggling. And how other calibers that were not doing much, have now evolved and are the "hot stuff".
Many calibers that are capable, get swept up to erodible factors such as: recoil, barrel-life, component costs, lack of quality components, etc........
These elements end up plaguing the caliber enough that they also fall to the way-side.
Couple major aspects in 600/1000-BR is CONTROLLABLE RECOIL and TRACKING.........
I feel it is safe to say you could have the most accurate rifle & ammo at a match, but if the tracking is poor, the precision accuracy will be hindered and final results will suffer. But the person on the bench next to you with a capable setup, that has good tracking will have a great chance of beating you, because there whole "system" is working better and have more precision capability, with shot to shot repeatability.
My answer to your question: "and at 600yds...is the 6br better enough to choose over a 6.5cm or 260rem?"
- as long as you can produce handloads with consistency enough to match or better the "highly efficient 6mmBR family", you could have an advantage with the calibers you listed.
To beat them day in - day out, will depend how well you can repeat your own consistency.
An advantage IMO the 6mmBR-family has over some calibers (besides cartridge efficiency) is:
- They are "System friendly" <><> recoil, tracking, torque, balance, reloader-friendly, quality components,etc..
Best of Luck
Donovan Moran
