I wouldn't assign a lot of credit to BR competitors, their cartridges, or reloading..
Especially for the demands of HUNTING.
There is no merging of these disciplines
This is going to be a long-winded post. Here goes:
I agree completely. There are a lot of things that benchrest shooters do to obtain their accuracy that simply aren't applicable to hunting situaions. For hunting purposes, reliability in adverse conditions is a vital consideration. In benchrest shooting, that is less important.
In benchrest shooting, it is common to neck size (rather than full length resize). It is also common to load bullets to "jam" in the rifling. Though I am sure that there are folks who load hunting ammo this way, both of these techniques have serious drawbacks in the field and both can compromise reliability.
I would also go one step further and say that I believe there are quite a few shooters who attempt to apply benchrest loading techniques to factory rifles. In a precision custom rifle made to precise tolerances, where the action, bolt, chamber, and bore are all concentric, it makes sense to take pains to produce ammo that is equally precise.
Put that same ammo in a factory rifle with sloppy tolerances, and all that time spent at the bench obsessing over things like runout is a waste of time, IMO. If your ammo is perfectly concentric and your rifle is not, there is no way you are going to derive a measurable benefit from doing all the extra steps at the reloading bench.
Even if you are hunting with a custom rifle, the discipline is completely different. Benchrest techniques are designed to tightern your groups by fractions of an inch over long strings of fire. Depending on your discipline, the winner is determined by score or by measuring group size.
In the hunting fields, it is all about FIRST round hits on the vitals of the animal being hunted. Either you hit the vitals COLD BORE or you don't. You don't get extra points for hitting 2" closer to the center of the vitals or for putting 20 rounds in tight little groups on the vitals.
If you have your hunting rifle shooting with reasonable accuracy, your ability to adjust for conditions is WAY more important than squeezing the last tenth of an inch out of your groups.
Personally, I stop fiddling with my ammo when I am able to put together a combination that shoots into 1/2" @100 yards. Theoretically, that makes my rifle and load mechanically capable of approximately 5" groups @ 1000 yards. As a shooter, I am not able to shoot that tight at even 600 yards most of the time. Keep in mind that I am doing that at known distances from a bench or in the prone using bags or a bi-pod. From field positions and under field shooting conditions, I have no illusions of bettering that.
When I get to the point where the limitations on my long range accuracy involve my equipment rather than my skills, I will break out the concentricity gauge. Until then, my time and effort goes toward improving the nut behind the trigger.
Are there people who are better shooters than I am present on this forum or in the game fields? Of course there are and lots of them. However, I would submit that there are no more than a handful of shooters on this forum who can shoot well enough in the field to tell the difference between a 1/2 MOA and a 1/4 MOA rifle under field conditions.
Having said all of that, here are the things that I consider to be important when assembling accurate hunting ammo for my non-custom rifles:
1. Case trimming to ensure that the case mouth is square to the case head. This is most important for the initial use of the case. They all get trimmed to the same length as a byproduct of doing this, but I believe squareness of the case mouth to be the most important benefit of doing this. FULL LENGTH resize to ensure concentricity prior to performing ANY case prep operations.
2. Use less temp sensitive powders. That normally spells extruded powders. If using extruded powders, take the time to hand weigh each powder charge. Doing this will go a long way toward reducing or eliminating problems with vertical spread.
3. Take the time and expend the rounds necessary to find your rifle's preferred seating depth with a given bullet. A lot of people want to adjust in increments of .005" or .010" to test this. I believe those increments to be too small. Test in increments of .030" or .040", starting from touching the rifling and working your way back in several increments. Fine tune in smaller increments from there, if you feel the need.
None of this takes exotic tooling. It mostly takes patience and reasonable attention to detail.
My final piece of advice is that hunting ammo should be assembled using full-length resized, once fired brass and should not be loaded to touch or jam in the rifling. For long range hunting, I believe it to be OK to single feed your rounds, but that is best left to personal preference.