Shane's followup:
Larry,
I’m with Brian and think it would defeat the purpose of this cartridge to neck turn ever piece of 223 brass run through it. I’m in total agreement with the 0.261 neck diameter. You’re right Larry, better to be a little tight, than too loose, we can always open it up a little. So 0.261, that means this will be a tight necked cartridge. I checked my .30-06 Match reamer drawing, and the neck dia. is less than .001 larger than loaded case neck dia. So, the 0.261 should work. I do think we may have early pressure signs, and case manufacturers tolerances (for the .223 cases) may affect performance significantly, with this tight neck. I will check all this out during load development. I may do some .221 FB vs. .223 comparisons during the latter part of testing. I will measure my bolt face tonight, and get back to you. This is going to be great.
Jed,
What is the neck thickness of the brass you made from the .223 cases? When I do finally get that Lee die to you, can you run a few cases and test to see if the die will size them down enough. I’m wondering if we may need to polish, the mandrel, off half a thou or so to get the brass down to proper inside neck diameter. Just thinking that thicker brass at the neck will be real springy. Again, it would be better to start with too little neck tension, then too much. I can always polish off some more if I need to. I use the, “if I don’t have to force the bullet into the case with the bullet seating die, and I can’t push it any further into the case with my finger, then its good,” test. I know you have already figured all this out in your head, I’m just talking this out for my sake.