Neck turning

[Richard Coody]

Well i have avoided this task for years. All the horror stories i have read kept me from going for it. Have been collecting the tools for some time.

Got my starrett ball micrometer last week. I have been checking my lapua 6br brass with a sinclair neck checker. Looked pretty good. Well playing with the micrometer i found neck thickness varied from about .012 to about .0135 on the same piece of brass. Don't know if that is good or bad but it did explain why when using my 21st century concentricity gauge it reacts up and down several times with .0005 movements on a rotation.

I said it is time to see if i can fix this. Pulled out my unused PMA tools neck turner with some apprehension. Set up my trimmer drill motor in the vice just like i do for trimming. Read the directions. Measured a thick spot on a case, .0135 and used that mark as a gauge for the cutter. Took a..001 off that and ran a case. That brass cuts like butter. Measured neck thickness with the micrometer and adjusted the tool .0002. Anyway measured the first 10 or so and it was very consistent at .0125 except for the .012 spots. Didn't want to take off too much.

Did 50 and it was a.breeze. Is a .0125 neck thickness about right for 6br lapua brass?

Oh i used my little piece of scotchbrite pad that i use on my chamfers to smooth it up. Worked great. You couldn't tell it had been turned just looking at it.

That 30 degree cutter fit that shoulder angle perfectly.

Anyway i overcame my fear of neck turning. I actually enjoyed it

 

[dedogs]

Is a .0125 neck thickness about right for 6br lapua brass

Richard, Need to know what your chamber's neck diameter is to answer this question. Also is this new brass or fired? dedogs

 

[Richard Coody]

Typical shilen savage prefit 6br norma.

It is some fired brass. I have read about not turning fired brass but i saw no practical reason it wouldn't work. I ultrasonic cleaned them, ran them through a full length sizing die and then the expandrel mandrel. Had a nice tight fit. They will be annealed before loading.



Wanted to refine my technique before starting on the new lapua brass. Just cleaning them up. Not trying for a certain neck thickness at this time. They are all consistent now.

 

[joshb]

That's pretty much my experience. A lot of "fear and trepidation" before even trying it. Very satisfying when done. PMA makes a nice tool. It hasn't become the "pain in the arse" I've read about, yet.

 

[Bart B.]

Note that with perfectly straight resized cases, for each .001" change of neck wall thickness, the mouth/throat center is .0005" off the case outside dimension center. Bullets will be about the same amount off center to the bore when fired. And a tiny bit crooked as always; back end of case body will be a mite off center in the chamber when fired.

Your tiny spreads are well inside the "no worries" range.

 

[RampedRaptor]

"tolerances stack" is a pretty common phrase that most reloaders try to inhibit. I use to neck turn and then switched to shooting strictly Lapua brass and haven't since. I don't own a device to check concentricity and I know I should. I'm 95% sure if I did I would probably be back to skimming necks. Good job OP.

 

[dedogs]

Wanted to refine my technique before starting on the new lapua brass

That is a very good idea, no sense practicing on new brass. I don't know where you read that you shouldn't turn fired/ used brass. Many of the shooters I know ( and myself) turn our BR brass a second time after they have been fired twice. Just another light skim to ensure everything is concentric. I have not experienced any detrimental effects on paper doing this. Others may chime in with different opinions.
Your .0125 thickness should be fine for your chamber but the target will tell you if it's right. dedogs