Wasskeet, those same Benchrest shooters agging .247 could take their hunting rifles and make them shoot amazingly. The guy that will agg .247 will shoot some low 1's, perhaps a zero, then get caught by a wind change.
Knowing how to tune the load to the barrel harmonics is where the Keys to the Kingdom lie.
Having a wind flag out 15 yards in front of the bench where you are shooting, takes your shooting to a whole new level with highly tuned hunting rifles, custom or factory. Wind watching, left, right, straight at you or in your face. Catch the switches and cut your groups in half, when I learned this in 1985, my load development took much less time. Shooting a ladder gave me much more definitive information. The wind flag was a 1/2" x 30" piece of red yarn stapled on the top of a 1"x2" that was 30" long, sharpened on one end.
Eric Cortina makes a Tuner that can be installed right behind the can, independent of the can. This tuner looks like a sleeve with numbers etched on it. The addition of a Tuner on your barrel will take your accuracy to levels that you would have never thought possible, factory and custom barrels. I work up my best load with the tuner screwed to the rear. After I find my best load, and it will be shooting tiny groups at that point, then I start moving the tuner in 2 notch intervals(fine-tuned later, if necessary). Usually, by the time I get to the number 6, the bullets are going in the same hole. What I thought was a great group, not has become remarkable. The key is to verify in 3 to 6 Three-shot groups in a row, verified on subsequent days. I do not make the process any more complicated than that.
We started putting large weights on the outside of our barrels in the 80s when shooting incredible numbers of p. dogs, rock chucks, and jackrabbits. The large weights, 2"x4" in dia, were supposed to stop the muzzle climb, at that time, few of us were aware of muzzle breaks. The sweet surprise that the weight on the barrel tuned the barrel with little effort, was a Bonus. A friend hunting with me invented and patented the Browning Boss based on the concept.