Neck Turning Question

[nickster]

I have a 6BR barrel on my 40X. It was supposed to be a no turn neck and ended up being .271. At least that's what is says on the barrel. The Norma brass I have looks like they are possibly turned a little and the wall thickness on most of them is ~.012". That should give me a finished round at ~.268". I've been shooting these for a while and just for the heck of it I started measuring them. Some are closer to .269" and one was .270" finished. No real signs of pressure though on the spent brass. Anyway I have a Sinclair trimmer and want to just clean up the necks and make them all .012" so I don't have to worry about any of them being too tight. I also want to take care of any donuts that may have formed. The Sinclair trimmer I have is not marked but it looks like the NT1000 on their site. I have a mandrel marked X24X which I believe is an expander mandrel. I measured it with a mic and it's .2417". Does that sound about right for the expander? What size turning mandrel do I need? Sinclair is out of them so after looking at Ebay I found them at .240" and .241". Also, a lot of the brass in question are primed already so I was going to use a dry lubricant. Any suggestions on that?

Thanks

 

[jepp2]

I measured it with a mic and it's .2417". Does that sound about right for the expander?

Probably, but they vary slightly given the same manufacturer, and more widely between suppliers (21'st Century vs Brownells for example). I have a new 21'st Century T24 TiN mandrel that measure 0.2407" for me if you are interested.

so I was going to use a dry lubricant. Any suggestions on that?

If your clearance is great enough, that could work. I would probably be more inclined to use some Imperial, and remove it from the case neck after turning with a Q-tip, but that is just me.

 

[jepp2]

The TiN is available at Brownells and it is 15% off this weekend.

SINCLAIR INTERNATIONAL 6mm (0.241") TiN Turning Mandrel SKU: 749019014 | Brownells

Check out the SINCLAIR INTERNATIONAL 6mm (0.241") TiN Turning Mandrel SKU: 749019014 available Online at Brownells Today and many more Case Neck Turning products are available in our Reloading Department.

www.brownells.com

 

[Bill Norris]

My expanders for turning measures the exact caliber size. You need clearance there so the brass don't run hot and gall while turning several pcs. (hundred or even more) Very important as Jack Neary says in one of his videos ONLY expand immediately prior to turning the neck. Meaning do not expand all at once. Expand one and turn it one at a time to help keep heat down to min. As heat builds the cut will vary and therefore not be the same across all pcs. of brass. Lube on the mandrel and inside necks is important as well.

 

[LCazador]

Turning mandrel should be about .001" less than expander mandrel. I would not recommend turning necks with a primer in the case. The case holder indicates in the primer pocket so having a primer there could result in some loss of concentricity. I've never had good neck turning results with a dry lubricant.

 

[Bill Norris]

Turning mandrel should be about .001" less than expander mandrel. I would not recommend turning necks with a primer in the case. The case holder indicates in the primer pocket so having a primer there could result in some loss of concentricity.

Absolutely hard to keep it centered with a primer in place.