Neck turning question?

[Shoalwater]

I did a search but could not find the answer to my question. I have decided to start neck turning and I was wondering do you mic each case neck and turn the necks down to the smallest measurement of each individual case or do you mic all the cases and then turn them all down to smallest measurement of the smallest case neck thickness of the entire lot of brass? Thanks for the help.

 

[J E Custom]

I did a search but could not find the answer to my question. I have decided to start neck turning and I was wondering do you mic each case neck and turn the necks down to the smallest measurement of each individual case or do you mic all the cases and then turn them all down to smallest measurement of the smallest case neck thickness of the entire lot of brass? Thanks for the help.

The only reasons to turn case necks Is to make them uniform with each other, or in the case of some chambers that have a tight neck, to get a proper fit.

To make them uniform, only turn them enough to clean them up. you may have to re set the neck turner several times before you get all of them to clean up. or check the thickness all the way around and use the thinnest case to set up on.

I also recommend using a sizing pilot (Like the Sinclair tool uses) to true up the inside before turning the outside.

I would not recommend turning down to less than .010 to .011 minimum thickness if you can.

It is also best to turn them before the brass has been fired. (If they are not concentric your chamber will true them up and they will be very true). If they have been fired in a true chamber
the inside of the neck may/will be off center by the wall thickness error/difference.

J E CUSTOM

 

[frostop]

JE,

What would be the correct order of operation, Size, Trim than neck turn?

What would be wrong with turning fired cases? I ask because I am currently working with a 280AI that I have fireformed from 270?

Gary

 

[Shoalwater]

I have new Nosler 280 AI brass that I plan on turning as well. I was planning on neck sizing and then turning the necks, no need to trim as every case I have measured is dead nuts 2.525. I also have about 200 once fired 6.5 Creedmoor that I want to do as well so I too would like to have a better understanding.

 

[Mikecr]

You shouldn't turn necks beyond needed because every bit of that(beyond needed) adds to sizing requirement on reloading. More sizing equals more runout and more tension variance and possibly less brass life. So no, don't just turn em all to thinnest in lot, or any other value, without knowing what is actually right.

You should pick up a reloading book that covers turning. And really you should have done this and put together a plan before buying any turning equipment.
Have you measured your necks and determined that turning is even needed?

 

[J E Custom]

JE,

What would be the correct order of operation, Size, Trim than neck turn?

What would be wrong with turning fired cases? I ask because I am currently working with a 280AI that I have fireformed from 270?

Gary

My opinion is that you should pre size the inside of the neck first, then turn the necks all the same, then trim if it is necessary, and then size to load. It is the best way I know to form the brass concentric with the chamber.

If you use the sizing pilot first, it will true the neck only, but you will get a very precise wall thickness on the neck. but to true the case with the chamber it will have to be fired one more time
if it has been fired with differences in neck thickness.
(Your brass and chamber may be true but the inside of the case is not unless the neck wall is exactly the same all the way around (If it is you don't need to do anything except turn them to the same thickness) and if the necks wall is different, the different thicknesses move the bullet off center buy the difference in thickness.

That's why I like to size the inside of the neck with the sizing pilot, turn the OD of the neck(Using the correct fitting pilot) so at least when its fired the first time it does not move the inside of the neck off center.

I have also found that when sizing down a case/neck for a wildcat, I follow the same procedure
while the case/neck is the original size.

I use the 375 RUM for my 30 Texan and my 338 Texan and I turn them while they are still .375
so the first firing will center everything up perfectly. (When they are set up this way it is not unusual for accuracy to be less than 1/2 moa during fire forming.

This all sounds like a lot of trouble, and it is not necessary if someone is looking for 1 Minute of deer accuracy.
I MOA is easy, 1/2 MOA is hard, 1/4 MOA takes a lot more effort than 1/2 MOA and 1/10th MOA requires that we pull out all the stops and leave no stone unturned.

I hope that explained it well enough to understand.

Just the way I like to prepare brass for accuracy loading.

J E CUSTOM

 

[frostop]

Very good information, thank you for the replies.
I have seen a lot on neck turning but never really saw a good order or operations to follow.

Gary

 

[Shoalwater]

Thank you for the info JE, one other quick question if you don't mind. How much larger do you want the the camber neck than a loaded round? Reason I ask, is. I loaded a few dummy rounds and every one of them came in at .3105 on a loaded neck. The reamer I am having made has a spec of .3155 for the neck diameter. Is .005 to much space? I'm afraid that number might grow another thousandth or two if I turn the necks on this lot of brass. Still waiting on my ball micrometer to get here so I can accurately measure the necks on the brass. Thanks for your help.

 

[J E Custom]

Thank you for the info JE, one other quick question if you don't mind. How much larger do you want the the camber neck than a loaded round? Reason I ask, is. I loaded a few dummy rounds and every one of them came in at .3105 on a loaded neck. The reamer I am having made has a spec of .3155 for the neck diameter. Is .005 to much space? I'm afraid that number might grow another thousandth or two if I turn the necks on this lot of brass. Still waiting on my ball micrometer to get here so I can accurately measure the necks on the brass. Thanks for your help.

Some like .003 but that is a little tight for my taste. For precision reloads (neck turned) .004 is minimum and the .005 will be perfect. .006 to .008 is normal for hard service rifles and dangerous game rifles so they will work in a less than pristine chamber.

If it ends up more don't worry, size the brass so it has little or no head space and the shoulder will center the round. I personally like to feel the round when I chamber it (No slack in the bolt).

J E CUSTOM

 

[AZShooter]

good tutorial on neck turning:

Neck-Turning Basics within AccurateShooter.com

 

[frostop]

That's what I've been looking for!!!