At what range is accuracy affected with greater than your standard? Very interested since I am wrestling with this now.
I think it's difficult to correlate with absolute certainty the effect of run-out on precision, accuracy, or ES, particularly considering differences in rifle chamber, bullet design, seating depth, etc. To your question, while range is certainly a function, I think more about the the angular dispersion(MOA) which more often then not correlates at longer ranges with a well designed load(stabile bullet and low ES). My standard of run-out was established quite a few years ago when I was heavily involved in 200/300 yard Egg Shoot Competition. This is essentially a bench-rest game, requiring the rifle to consistently shoot relatively long, time limited strings(10-20+ shots) into <.5MOA, the minuimum requirement to hit an egg at 300 yards(Much harder the it sounds!). During this rather intense period of shooting through thousands of rounds at actual eggs, sighter groups,and practice it appeared that the uniformity and reduction of fliers was related to the degree of run out with my loads. Initially, the bulk of my shooting was with a 308 hand loaded with 168 or 175 Sierra SMK's. I stumbled upon this when comparing my loads which were near identical in velocity, and POI to the Factory Gold Medal Match. While my actual groups size, on average, were smaller then the factory loads by about .25MOA, the factory ammo was typically more symmetrical in shape with fewer fliers. In an attempt to figure out the difference to my loads, I measured several different lots of the factory Match ammo, the average runout rarely exceeded .003", with most in the .001-.002"range. Mine were running .003-.005". When I "finally" reduced my run-out to <.003" and I found my groups more symmetrical with fewer fliers, and improved ES.....Most importantly, I improved my Egg Shoot scores! Thus, my .002" stantard, which I have since then, simply applied to all my precision loads. Coming back to the question asking, "What range is accuracy effected?" For those Egg Shoots it was 300 yards. In the case of my LR hunting, it's hitting the particular animals vitals out to 1000+ yards. I think a low degree of run-out(<.003") can only improve the chances of performance consistency, and the confidence that your average group(or shot) will be within your target, at whatever the calcuated range(WEZ)....IMO.
