I've had tight spec'd chambers which called for SB dies - which I ordered specifically with that in mind. For all other AR's, the "need" for SB dies is mostly nothing more than online rhetoric. I have a couple AR's for which I only neck size even, and only need to do a FL every 4th loading (5th gets inconsistent, so I size 4th).
Originally Posted By: Tbone-AZI did disagree with a statement that a deviation of .1gr of powder wouldn't have much of an impact, after saying that weighing the cases for weight, using all the same brands, cleaning the primer hole, and primer picket, trimming, chamfering inside and outside the rim, playing with jump and a couple of other things to get the most consistent and accurate load to work with each rifle and it's whip/harmonics. If the stated goal was to get the most consistent seat, jump, and combustion, and then harmonics/barrel whip to get the best accuracy possible.
Then wouldn't it stand to reason that you also do the very best you can (within reasonable effort) to make sure that the load of powder going in is as close to the same weight as you can manage? shooting through a chrono tells a different story in my limited experience.
Especially if you get into looking at lots and batches for powder and primers?
A guy has to decide where he needs to draw his line, and too many guys arbitrarily draw our line based on the precision of their electronic dispenser. A guy could easily argue +/-0.1grn of powder is a HUGE deviation, or a guy can just as easily argue it's not. So a guy has to determine whether 0.1grn makes a real difference in their loads. I have a scale at work where I can measure my bodyweight down to the hundredth pound, but my driver's license doesn't say 198.73lbs, it just says 199. Drive over scales often only weigh to within 20lbs, so I'm either 180 or 200lbs, that spread makes a difference for my body weight, but doesn't matter much when I'm loading 84-103,000lb GVR. When I weigh charges on my Mettler, I can load to MUCH greater precision than +/-0.1grn - I can load to within fractional kernels. But... On the other hand, with proper load work up, deviation as big as +/-0.2-0.3grn doesn't significantly change the MV, SD, or ES of many of my loads.
The entire industry behind load development is predicated upon finding a load in which 0.1grn becomes insignificant. OCW, Ladder tests, etc all rely upon finding that "window" where relatively large changes in powder charge don't result in proportionately large changes in MV.
So I'd tend to agree with the article - if I have a load which needs tighter than 0.1grn precision, I know it's not the right load for that rifle and bullet.