by Glen Zediker
Weight is another common means of case segregation. I can’t imagine doing this job without an electronic scale, because I have done this job without an electronic scale.
Most set a percentage tolerance for weight, not so much seeking identical weights. Otherwise, you’ll have to sort a lot of cases. The physically larger something is, the more variation can exist. 1% is pretty harsh; 1.5% is more reasonable; 2% is commonly used. You’ll figure out the viability of your segregation criteria after you go through a few dozen cases. If you have 10 piles, then the criteria might be too harsh. If you use a percentage, certainly then larger caliber cases will have a greater overall weight tolerance/variance than smaller ones. Think of it as: 1% in a 90-grain .223 is 0.90 grains, and in a .308 Win., it’s 1.7 grains, or about double.
This segregation method or means is nearly universally adhered to by NRA Long Range competitors. The belief is that weight reflects on case capacity: heavier cases, lower capacity; lighter cases, higher capacity; and, mostly, same-weight cases, same capacity. Most are not looking for “light” or “heavy,” just “the same.” There’s a correlation between wall thickness consistency and weight consistency, I’m sure, but it’s not direct.
Don’t confuse the ultimate results from an exercise in segregation. We will get what we look for, but that’s all we know for sure. No doubt, the combination of segregation by weight and wall thickness should result in the best of the best, but, dang, that might also result in a very small pile.
Important: Fully prep all the cases prior to weight segregation! The reason is a matter of reliability in the result. Primer pocket uniforming, length trimming, chamfering, and inside flash hole deburring all require removal of brass. The amounts will vary in each instance. I’ve collected and weighed enough shavings from prepping before and can tell you that, if you’re segregating by fine increments, you’re kidding yourself if you don’t follow this advice. The amount of brass removed does not at all directly reflect on the quality of a case because the areas where the weight is originating don’t influence the “overall” quality. But it can influence the scale. Which is the criteria, right?
The procedure used by most winning 1000-yard shooters is to segregate by weight and then outside-turn the case necks to make the neck walls consistent. Again, it ultimately will be a better test if the neck turning is done prior to weight segregation. At this point, however, we have done a lot of work.
So, looking back on the last article, which was segregating by neck wall thickness variations, here’s what I think: If most of your shooting is under 300 yards, go with neck-wall thickness. If you’re covering more real estate, I’d suggest sorting by weight. No doubt, a combination is the ultimate.
Since I focus on concentricity both before and after bullet seating, I can’t say any weight-segregated cases have outperformed my concentricity-selected ammo at 600 yards. I also know, from experience, that the cases I favor are demonstrably low in weight variation. For me, segregating by wall thickness makes more sense. I use the same brand/lot for 200, 300, and 600 yards; the difference is the load. I am pretty much looking for a good, better, best to coincide with my needs for accuracy at 200, 300, and 600 yards.
This might sound contradictory, but it seems that when firing on targets at short range, where weather conditions aren’t overly influential and bullet limits are not nearly being approached, it’s superior concentricity that prints the best groups. Further on down the pike, though, concentricity is important, certainly and always, but it’s really the consistency of bullet velocities that gets “10s.” A good long-range shooter (who can keep a handle on condition-influenced corrections) will lose more points to elevation shots than to wind. High-low shots are, for a Master or High Master, pretty much the fault of the ammo. The reason velocity deviations are just not that important to short-range groups is solely a time-of-flight answer. The longer a bullet is in the air, and the slower it’s moving, the farther and farther it flies, the more initial velocity consistency factors in.
The preceding is specially-adapted from material in the forthcoming book “Top Grade Ammo” coming (very soon) from Zediker Publishing. Check BuyZedikerBooks.com and ZedikerPublishing.com for more.