Neck turn and Neck tension questions

[Bush Man]

Ok I'm getting tooled up to neck turn 200pcs of 260rem lapua brass. I've got K&M neck turning tool and expanding iron for .260. Mititutoyo ball neck mic should be here tomorrow.

The barrel will be chambered to .295neck
Also redding S bushing die with a couple bushings. .291 .292

So is it correct to first expand neck with k&m iron, and then turn neck.
After neck is turned use fl die to size neck for seating?

Now what is ideal "neck tension"?? .002 tight?

What is ideal wall thickness with lapua brass?

Never neck turned yet so any advice is appreciated.

 

[roberti11]

For your chamber you would like 2-3 thou neck clearance.

Hence final neck with loaded bullet should be .292, you would use a .290 bushing to give you .002 thou of squeeze.

Lapua brass is usually 14 thou, if you do not touch it, you will have .028 + .264 = .292 neck on the loaded round.

I would skim around 1 thou to take you neck thickness down to 13thou, this will give you a loaded round at .290. If you brass is a bit thicker then I would try to keep the neck thickness between 13 -14 thou so that the final loaded round is close to .292.

You have the process correct, use the expander first, then turn the necks.

2 thou of squeeze is good, but the bushing you need will depend on thickness of the turned necks.

Formula for the bushing is (2*neck thickness + bullet dia)-.002

Exapmple: Neck is 13 thou, bullet is .264
bushing = (.026 +.264)-.002
Bushing = 0.288

 

[Kodiak99317]

Full Length size your brass first, without the expander in, leaving the necks really tiny and tight. This pushes the lumps inward. Then expand with your expander mandrel, pushing said lump to the outside of your brass, then neck turn.