New Brass/Neck Turning

[TimP]

I have some new Lapua brass that I am going to prep for a new build. It will be a tight neck minimum body dimension chamber. I intend to run the brass thru a standard FL sizing die prior to trimming then neck turn the brass. So the questions I have are. 1) Should I use the expander button when I FL size the new brass. 2) If I don’t use the expander button will my expander mandrel for my neck turning tool require too much pressure to open up the necks. 3) Should I use a small base die and if so what are the benefits for a bolt action rifle. 4) I already own a Redding Type “S” Match FL Die Set but need to purchase a standard FL size die. Would it be beneficial to buy a small base standard FL die to run the new brass thru but then use my Type “S” bushing FL die for shoulder bumping and neck sizing. Don’t want to have to buy another die if I don’t have to.
Thanks, your input is appreciated.

 

[Steve Blair]

I rarely size new brass before turning, especially not Lapua or Norma. What is the base brass and how much are you expanding the neck?

 

[TimP]

I rarely size new brass before turning, especially not Lapua or Norma. What is the base brass and how much are you expanding the neck?

The brass (.308) measures .46870 at the base. As is I will have to expand the necks .004 - .005.

 

[Steve Blair]

I use an expander die for that operation and currently use a Sinclair die. If I bought another, it would be a 21st Century. The 21st Century unit is about $20 and uses your present expander. My F-T/R rifle has a tight chamber neck and I go through the same process as you.

 

[rjnallie]

If it is new brass, I would trim the lengths uniformly and try your neck turning expander and see if it expands it or it is loose. I have had the same problem by running a standard full length (RCBS) die and then trying to run my expander. You could mic your neck O.D. and measure your existing neck wall thickness to come up with a neck I. D. Most turning expanders I have measured are .3065

 

[fdshuster]

Tim: Regarding your question #3: I have and use small base dies, but only use them when I start to get hard bolt lift after firing, and/or the "click" at the top of opening the bolt. In every example, those two issues are resolved with the small base dies.

New brass is already minimal dimensioned, so there should be no need for a small base die. The problem usually does not start until the brass has been fired 4 or 5 times, depending on pressures generated by the load.

I never run new brass into a FL sizing die before loading. I run the case necks over an expanding mandrel (Sinclair), outside neck turn if required, inside taper neck ream the case mouths, load and fire.

 

[Leaddog]

I use the 21st Century Turner and lathe with excellent results. A 7v DeWalt power screwdriver drives the lathe.

New Lapua brass only needs the necks expanded before turning. Get the titanium nitrate turning arbor and expanding mandrel.

 

[jlow]

How do you guys find the new Lapua 308 brass in terms of headspace?

I am thinking if there is more headspace that what is good for my chamber, I may not be able to adjust it to the proper headspace and this may affect any neck resultant neck turning. I know when it is fired, the shoulders will move forward to chamber size but my guess is it will take more than one turning before it settles down? There is also a question of how consistent the headspace of the new brass is?

 

[Leaddog]

Jlow - Since I have no turn chambers in my .308's, I only neck size skim for neck wall consistency. The last several hundred pieces of Lapua brass I've gotten has been fairly consistent. Headspace within .0005.

Your idea of two neck turns is valid. I think Johara1 has written about this a couple of times on this forum. Of course, he was talking Dasher brass, but the principle is the same.

 

[jlow]

Thanks Charlie!