Should I neck turn?

[josebd]

Cartridge is 22-250,a fired round measures .2535,loaded round measures.252
Mostly interested in better concentricity

 

[Ledd Slinger]

Yes. I turn the necks on every case no matter what the neck size is on the chamber. Some of my chambers have tight necks and require it, others I just clean up for better concentricity. Either way turning gives more consistent neck tension and if cut onto the shoulder properly, it will help to deter the formation of donuts.

 

[Bart B.]

If the neck wall thickness spread is no more than .001", I wouldn't bother. That's measured the same distance back from the mouth all the way around. There may be .0005" thicker brass close to the shoulder.

A .001" spread in neck wall full length sized without an expander ball will position a bullet about .0005" off center in the chamber neck when fired. Assuming the case neck isn't bent.

If you can see better accuracy by turning necks all the way around, do it.

 

[1shot]

Yes. I turn the necks on every case no matter what the neck size is on the chamber. Some of my chambers have tight necks and require it, others I just clean up for better concentricity. Either way turning gives more consistent neck tension and if cut onto the shoulder properly, it will help to deter the formation of donuts.

^^^^^^^^^^^^^^^^^^
Exactly what he said. Besides, I like turning brass!

Lloyd

 

[1shot]

Yes. I turn the necks on every case no matter what the neck size is on the chamber. Some of my chambers have tight necks and require it, others I just clean up for better concentricity. Either way turning gives more consistent neck tension and if cut onto the shoulder properly, it will help to deter the formation of donuts.

^^^^^^^^^^^^^^^^^^
Exactly what he said. Besides, I like turning brass!

Lloyd

 

[Richard Coody]

well no doubt if you take a micrometer and measure your neck thickness at several points even with lapua brass you will probably find about a 0.0015 difference maybe more. this certainly will translate into concentricity on a loaded round. it also will cause slight differences in neck tension.

i too enjoy neck turning. but i enjoy all aspects of precision reloading.

but reality is if you aren't looking for that last little bit of accuracy that 0.10 improvement in group size you probably won't notice the difference on target.

 

[LA50SHOOTER]

Cartridge is 22-250,a fired round measures .2535,loaded round measures.252
Mostly interested in better concentricity

I would for three reasons, better concentricity, more uniform neck tension, and last but not least to get a little more neck clearance. Based on the numbers that you’ve provided your running 0.0015 total clearance which is less than one thousands per side. I’ve seen (in a tight neck 6mm BR) where having a little more (0.003) clerance at the neck actually improved accuracy in the same load. IMO if your brass is producing loaded rounds that are 0.2520 then you may want to consider taking approximately 0.0007 to 0.001 off when neck turning.

 

[boltfluter]

Cartridge is 22-250,a fired round measures .2535,loaded round measures.252
Mostly interested in better concentricity

Jose,

Go for it! Really nothing to loose and possibly some accuracy to be gained. When looking for that last little bit, leave no stone unturned. Let us know how it goes!

Paul

 

[rwj]

I’ve seen (in a tight neck 6mm BR) where having a little more (0.003) clerance at the neck actually improved accuracy in the same load.

As I’ve recently become a member of the neck turning club... how much clearance between the case neck OD and chamber neck ID is considered to be too much?

 

[JFrank]

Personally I run a .272 no turn neck, my loaded round is .269, I believe.003 is just about right.
YMMV

 

[Richard Coody]

I would for three reasons, better concentricity, more uniform neck tension, and last but not least to get a little more neck clearance. Based on the numbers that you’ve provided your running 0.0015 total clearance which is less than one thousands per side. I’ve seen (in a tight neck 6mm BR) where having a little more (0.003) clerance at the neck actually improved accuracy in the same load. IMO if your brass is producing loaded rounds that are 0.2520 then you may want to consider taking approximately 0.0007 to 0.001 off when neck turning.

don't forget brass spring back in that equation. the neck on that fired round is not chamber size. probably at least a .001 less. so that puts you more like .0025 to .003 which meets average clearance.

 

[LA50SHOOTER]

As I’ve recently become a member of the neck turning club... how much clearance between the case neck OD and chamber neck ID is considered to be too much?

That is up for debate IMO.
I know that shooters have done well with No-turn chambers using Lapua brass in the 6mm's - And I'm assuming that the chamber necks were cut with a reamer having 0.003 to 0.004 clearance over the loaded round.

The end result of having a larger diameter neck is working the brass more, both when firing it and then getting it back down to where it holds bullets with correct tension. - I personally wouldn't go over 0.005 in an accuracy type chambered rifle.

I personally run a 0.003 (total) neck clearance on 20 & 22 calibers.
0.0035 on a 6mm, 0.004 on 30,338 & 375 calibers. on 416 & 50 I run 0.0045 to 0.0050

 

[LA50SHOOTER]

don't forget brass spring back in that equation. the neck on that fired round is not chamber size. probably at least a .001 less. so that puts you more like .0025 to .003 which meets average clearance.

Good Point Richard.

And I'm sure most of us can agree that the spring-back depends on the condition (softness / hardness of the brass)

I base measurements off of chamber reamer prints and taylor brass accordingly regarding neck turning.

 

[rwj]

Personally I run a .272 no turn neck, my loaded round is .269, I believe.003 is just about right.
YMMV

Same dimensions for my 6BR. But after multiple firings, donuts are forming near the case neck/shoulder junction which is causing inconsistent bullet seating force. Removal results in reducing the neck OD by ~.001” for a total diametral clearance of .004” for the loaded round... at least until barrel replacement.

 

[Richard Coody]

Good Point Richard.

And I'm sure most of us can agree that the spring-back depends on the condition (softness / hardness of the brass)

I base measurements off of chamber reamer prints and taylor brass accordingly regarding neck turning.

since he is running a 22-250 i doubt he is looking for benchrest accuracy. doubt if he has a reamer print either. he could do a chamber cast but i really think that would be overkill in this situation.

 

[butchlambert]

A big waste of time, but if you are bored, go for it.

 

[Ccrider]

Interesting thread. I have a 257 STW that I turned the neck on five cases just to see the difference. Just need time to shoot them. I had to take off quite a bit to clean them up.

 

[Ccrider]

The only way you will know is to test it for yourself.

 

[B23]

I haven't seen it mentioned, but don't you kind of need to be using some kind of a bushing die if you plan to turn necks, also??

 

[Ledd Slinger]

Nowadays I design my reamers around a specific bullet I want to use. I calculate free bore so when the ogive is touching the lands, the bottom of the bearing surface is just above the neck/shoulder junction. This way when seating to the lands or with a slight jump or jam, I don't have to worry about donuts affecting my neck tension. Still turn necks down onto the shoulders tho.

When building a custom wildcat, I also like to use case designs with sharper 35 and 40 degree shoulders and minimum body taper. Harder for brass to flow into the neck with straighter body and steeper shoulder angles. Less chance of donuts and not as much trimming due to less case growth.