Well...now I know what resizing die I'll be using from now on. I shot 5 shot groups with loads from the Lee Collet, the Redding Type S FL bushing die, and the Redding standard FL sizing die. I adjusted both FL dies for a .002 shoulder setback, or at least as close as I could get to that, using Unclenick's suggested approach. The bushing die reloads grouped into about an inch, if you don't count one flyer (which I guess we have to count). The standard FL die grouped into 1 inch. The Lee Collet reloads grouped into 3/8 of an inch. That's 5 bullets in the same darned ragged hole. Amazing. Same 5 cases, so no chance of a couple of bad cases causing problems.
Now somebody is going to say that "it's just 5 bullets, so it isn't statistically significant". So let em say it. That's still 5 bullets in one ragged hole that only shows sign of having had 3 bullets hit the paper, so the other two were inside that 3/8 of an inch. That's significant in my book, particularly after all the shooting I did yesterday.
So here's the result of the testing:
- Die that led to best grouping. The Lee Collet Die
- Second place goes to the Redding standard FL sizing die
- Third place is either the Redding FL bushing die or the Redding standard NK die, or maybe using the FL die for Partial Sizing.
So...is this the answer for you too? Darned if I know, but I can tell you that the inexpensive Lee Collet Die let me shoot the best 5 shot group that's ever come out of this rifle. No other die was close.
I might consider doing some more testing and die adjusting, but my brass is getting tired and I'm back-ordered just like you guys are.
Thanks for listening.