Neck size or FL size 6br?

[BoydAllen]

Years back, when I first got my first concentricity gauge, I took a look at every sort of ammunition, factory, and my loads (no turned necks or custom chambers), produced by various types of one piece dies (with expander balls), and that reloaded with collet dies, which was the best and most consistent. I was a long ways from benchrest and custom reloading equipment, but even then I could easily see that the collet dies were, far and away, the winner, in runout and consistency. Many years later, when I was playing with a bushing type FL die, trying to figure out how almost perfect fired cases became somewhat less perfect FL sized cases, usable, but less perfect. At some point I removed the sizing bushing from the die and sized a couple of old fired cases that I had previously run on the concentricity gauge. Same shoulder bump as I normally use....the cases were as straight as they came out of the rifle. Then, with another caliber, I tried combining the body die and the collet....and the rest is history;-) Do the experiment, just remember that spring plunger type ejectors can oval case necks, and that based on my testing, using the collet die first and then the body die, gives slightly better resultts. Another thing, if you need more neck tension, with the Lee die, polish down the mandrel, or order a couple in smaller diameters from Lee.

 

[BoydAllen]

Micrometer dies offer the convenience of being able to go back to a given setting or change a setting by a precise amount very easily, as long as the die setting, press, and shell holder are the same. They are a convenience, not a necessity. Lee is the only one that makes collet dies. Have you played with one...loaded some ammo? As I said above, you can play with neck tension by modifying mandrels.

 

[Flouncer]

Your post is appreciated. Yes, I use Lee collet dies for all my rifle loads. All things considered, the miniscule "FL" resize really isn't, it's a minimum body size with a shoulder bump. But, that die has to be very close to the chamber dimension, and used with utmost precision. Almost warrants purchasing the die, have the chamber and die cut with the same sword ??

Now that I think I understand, it is also apparent that I shoot lower pressure loads, because I can neck size my 6.5x55, 6.5-06 and 8x57 and they chamber easily. Er, that would be 4 or 5 cycles. When they don't, it's a primer not seated correctly. I am OK with the lower pressure loads, I am not comfortable pushing the envelope. My receivers are stamped 1912 and 1917.

A round with perfect concentricity read out could still not fit a chamber as well, nor shoot as well as a "FL" shoulder bumped load, right ??

 

[BoydAllen]

I am not sure what you mean. When I write FL it is short for Full Length. Full length dies may have just about any sort of fit to a given chamber, loose or close. If a loaded round is a good fit to the chamber, that is all that is required. There is nothing magic about full length sizing. I think that you may be trying to mix two very different situations. Lower pressure loads are a different reality than those that are higher. I think that one should use what works best, on the target, for a particular situation. By FL sizing my high pressure 6PPC loads with a die that hardly moves the brass, or you neck sizing for you old Mausers, we are both doing that.

 

[Flouncer]

Yes, I confused full length sizing with base size resizing. I sifted through this:

http://riflemansjournal.blogspot.com/2009/10/reloading-neck-tension.html

and this:

http://riflemansjournal.blogspot.com/2010/04/reloading-two-step-sizing-and.html

er, that's more than I am ready to take on now. So I'll go ahead with my plan for a new barrel in 6mm br, .272 neck, to shoot 90 and 105 Lapua out of the box. I'll learn with those cases and perhaps an investment of 100 new brass and 500 or so bullets, and a pound of VARGET. On my way......

 

[Steve Blair]

I could be mistaken since I neck turn 6BR. But, at least some folks have gone to a slightly smaller neck than .272 for "Blue Box" Lapua brass. I hope someone more knowledgeable on the subject will contribute.

 

[bozo699]

Steve,
I had my reamer ground for a .269 neck so I could turn them but I think for a no turn a .271 would be a good fit.
Wayne.