A Brief Overview
Short-range Benchrest shooting is divided in two major disciplines; group and score matches. Distances involved in registered matches are 100 yards, 200 yards, and 300 yards.
These days there are two undisputed 'champion' calibers that dominate each discipline separately; the 6PPC for groups, and the 30BR for score.
Back in the mid 1970's the 6PPC dethroaned the 222Rem as the most accurate chambering for Benchrest competitions, and dominated both the group and score matches. It was not until late 1990's - early 2000's that the 30BR proved to be a formidable chambering, extremely accurate and well behaved in staying in tune. Since then, due to these features and an undeniable advantage in scoring diameter (punched hole on paper), it is the winning chambering in score matches without any question.
But the Question Remains
Which of these two calibers is really the most accurate? This is a recurrent subject that has proven very difficult to assess, partly because we are comparing the accuracy of different caliber/diameter and weight bullets, driven at different velocities, and many times using different weight-class guns. Those that believe the 30BR is every bit as accurate, state that any practical difference in accuracy is not due to caliber liminations, but instead due to differences in recoil. This difference in recoil seems to matter, as of today there are very few LV (Ligth Varmint, 10.5lbs) guns chambered in 30BR that have proved to be competitive, with a very limited showing in national-level group matches.
Furthermore, would a caliber fitting somewhere in-between share the good traits of these two superb cases?
The 6.5mm BR
In some respects, the 6.5BR could be said to fit between these two calibers. It has greater capacity than the 6PPC by about 15%, but smaller bore diameter than the 30BR.
As a cross breed between these two calibers, comparatively speaking the 6.5BR should:
- Have similar internal ballistics to the 6PPC, as it shares the same case volume to bore area ratio.
- Have similar muzzle velocities as the 6PPC.
- Have less wind drift than both the 6PPC and the 30BR.
- Have less recoil than the 30BR, but slightly more than the 6PPC.
Based on my limited experience, I consider the 6.5BR to be more 'readable' than the 6PPC at 200 yards.
In score shoots it should be competitive with the 30BR from 200 yards and beyond.
A visual comparison
of the three calibers