I think the line between an inlet chamfer and a “taper” gets pretty blurry sometimes.As a person that has actually used a bushing in my Redding dies from SAC, let me clarify a couple of things.
I've spent a lot of time and $ in an effort to identify and reduce runout of loaded centerfire rifle rounds. I was appalled at the runout I experienced using Redding bushings in Redding dies. CRT bushings reduced the runout by over 50%. Eventually I started honing my FL die necks to the diameter I need them to be. But I would prefer to using bushings and not sacrifice runout.
So I watched a user review of the SAC bushings (not their entire die system as shown in post 3). The bushings have absolutely no taper in them. And my TIR using them is running is less than 0.001" (Redding was over 4- 0.006" generally). I was also experiencing with my 308 brass the phenomenon* where the case neck ends up about 0.004" under the bushing diameter. When using Redding bushings I had to size it down in two steps to avoid it from happening. Using the SAC bushing and a single step, my neck OD is the correct size.
I'm not declaring the SAC bushings the best thing since sliced bread, but this post seemed to cast doubt on them I haven't experienced.
(* per Redding)
The SAC bushings have an inlet chamfer and do not achieve the stated diameter until well up into the bushing.
You are correct that there is a portion of constant diameter inside the bushing— I.e. no taper.
But there’s definitely a shallow angle chamfer leading up to that part.
Sorry I was sloppy in my terms. I should have said inlet chamfer to avoid suggesting they never achieve a constant diameter.
I like the SAC approach, especially the inlet chamfer which leaves the donut unsized. Some people say this would make donuts form. I tend to think they will form anyway and this just gets them farther away from your bullet and helps you manage them.









