I can say that I am jealous! I often fight the CBTO spread and rarely have results that uniform.I use custom bullets, Micron seating dies and AMP press and there's hardly any variation B to O, recently loaded 200 rounds for a match and found two or three rounds where B to O was off by .001"
So if uniformity and precision is what you're looking for a quality components and tools are critical IMO
I'm guessing the set screws you mention refer to the Sinclair (LE Wilson) die since it does use a set screw to keep the seating stem in it's set position. Since I use their seating dies, I'm curious why you feel that set screw might, or will induce runout?and no set screws of any kind to introduce runout
What are you using to measure with?I use custom bullets, Micron seating dies and AMP press and there's hardly any variation B to O, recently loaded 200 rounds for a match and found two or three rounds where B to O was off by .001"
So if uniformity and precision is what you're looking for a quality components and tools are critical IMO
I thought it interesting in the interview Erik Cortina did with Jeff Pinehardt in which Pinehardt said he had never ben able to see any relevance to straight ammo vs not straight and thought it a waste of time being concerned about it.Years ago I did a test, comparing 6PPC loaded round straightness produced by a Hornady seater, and a Wilson. The cases had the same runout. The runout for the Hornady round was twice that of the Wilson. Admittedly this was the smallest possible sample, but I was familiar with what my usual results were for the Wilson. The most finely fitted seater that I own is one made by Don Nielson, it fits much more closely than any other, and is specific to a .262 neck 6PPC chamber. Since no micrometer is available for it, I learned to adjust it by the overall length of the stem and cap. Since then, for arbor press dies, that is my preferred method of adjustment.
The seating stem in the Sinclair die is hand fit to the bore of the die and so tight I doubt the set screw could affect anything. Also you could leave the screw out.I'm guessing the set screws you mention refer to the Sinclair (LE Wilson) die since it does use a set screw to keep the seating stem in it's set position. Since I use their seating dies, I'm curious why you feel that set screw might, or will induce runout?
Thank you.