Necks, to turn or not to turn?

[Heavies]

I have a no turn neck in a .308 win rifle, and I am planning on using this to shoot long range f-tr. I have been playing with no turning, skim turning, and full cleanup of necks, and I could see no appreciable difference in es/sd out of my reloads between them, using a final inside neck sizing method, all else being equal.

I do notice that when using a bushing die, seating force and neck tension will vary according to the neck thickness, as well as it should. However, sizing the interior of the necks should negate the slight variations in neck thickness, as seen on unturned necks, on well sorted brass, should it not?

When I use the interior final sizing method, all tension seems to be more or less equal on all brass, turned or not. Nothing scientific, just the 'feel' of bullet seating force. The feel is noticeable. As well as noticeable reductions in ES/SD from these more consistent rounds.

I have noticed a move of shooters using an expander mandrel as a final sizing option to set the inside of the neck to final dimension, pushing imperfections to the exterior of the neck.


My question, If using this type of method mentioned above, is there any reason I should turn my necks for a no turn chamber? Am I missing something?

Thank you for your thoughts.

 

[PALarson]

I have both type of chambers, I prefer the type that the necks need to be turned. Reason being I am able to tailor the necks to the chamber, However to your question, I believe that some brass tends to be thicker on one side than the other, with that said if so it would be valuable to skim the necks to insure the same amount of brass all around the circle.

Paul Larson
High Master

 

[Codeman]

I prefer to clean the necks and use a bushing die to control bullet tension.

Also uniforming the neck thickness also helps to align the bullet in the rifling.

 

[Larryh128]

I turn every neck on every case that I own. I like .013 for my purposes which is thicker than most are going to be using but it works well for no turn necks & most can be cleaned up. Even skim cutting 1 side only will help the case & the resulting neck tension.

 

[K22]

I'm not a competitive target shooter but I'm a serious varmint hunter and my standard is 1/2 moa for my varmint rifles. Also, I use standard dies without special sizing bushings. I've been reloading since 1970 but do not claim to be an expert however I'll share my thoughts and experiences. Calibers I shoot extensively are: 223, 22 250, 243, 308.

Like most shooter / reloaders, I'm always looking for ways to improve the accuracy of my reloads to squeeze out another .1" tighter group. I've considered turning necks for that reason but have not done it as of yet since I'm able to acheive my 1/2 moa standard and ever better with some rifles without turning necks. Each rifle has it's own lot of cases, full sized to bump shoulder back approx. .002. I discard a lot after 12 reloads. COL is custom set for each rifle to acheive the best accuracy.

I understand the technical reason for turning necks and do not dispute it but I've just not seen the need to do it for my purposes.

 

[Zia Hunter]

For most of my non-gas rifles, I neck turn new brass to achieve uniform thickness when neck sizing with bushing dies. Neck thickness generally in the range of .014. Even with high quality brass I have noted variation in neck wall thickness greater than .001. These loads are generally more concentric than those not neck turned as well as more accurate.

 

[Nomad47]

K22, I agree completely with you. But to get my long range 243 wssm to the accuracy I wanted at 1000 yards, I had to go to bushing dies and annealing. But I'm getting away with not turning the necks of the thick necked wssm cases.

 

[pmarauder]

I have noticed a move of shooters using an expander mandrel as a final sizing option to set the inside of the neck to final dimension, pushing imperfections to the exterior of the neck.


My question, If using this type of method mentioned above, is there any reason I should turn my necks for a no turn chamber? Am I missing something?

Thank you for your thoughts.

I think you answered your own question..... Upon new brass prep, it is common that we full size them, then trim to length. After that. you want to run an expander mandrel through them to "iron" out any imperfection in neck wall thickness and push them to the outside of the case. Even if you don't need to "skim" them for your chamber. It will improve your overall consistency in neck thickness to do so.
If you think your brass thickness is really crappy.... then i even keep my expander ball in my FL die to work the brass down and back again to really iron out the imperfections..... then run my expander mandrel back through again and skim them with the neck turner. This should provide you with almost perfect neck thickness of your brass. >> less run out >> uniform neck tension >> consistant bullet seating pressure...... Once im done, i remove the expander ball from the die. your chamber pressure will do the rest.
Thanks

 

[Shynloco]

From my experiences of more than 50 years of shooting and more recently reloading my own loads, PLUS readings on how to improve accuracy for Benchrest shooting (which is pretty much I do anymore - don't hunt), unless you have a "dedicated chamber" or custom built rig, experts say turning necks won't get you alot more accuracy. Now I've seen guys measure their chambers and then "turn" their brass accordingly and have some success. But just remember, unless you have a Match Grade barrel with veru specific measurements, general product rifles are produced with "general allowance" chambers.

Also to note, I see comments every once in while where guys mess up the order in which they treat their brass that is going to be shot out of one specific rifle/chamber. And that is, before you do anything to alter new brass BESIDES checking the length to make sure none are miscut at the factory and are too long, fireform the new brass before Full Length sizing and trimming brass. In other words, let the brass experience the expansion and contraction that occurs during firing. Now it doesn't have to be a full/normal load to fireform, but don't get wild and go way under minimum recommended loading because you can blow a rifle up doing that as well. I've not personally experienced that but saw it happen to a friend with a brand new Savage .223 bolt gun when he went low load of powder of around 1/2 a normal low load and KABOOM. Ended up with a three piece new rifle. My point is simply fireform before messing with the brass and do it in the rifle you intend to load for. All the mandrel stuff is great for improve accuracy as well, but again, do that as well AFTER you've fireformed. Just my thoughts and it seems to work for me when target shooting.

 

[Larryh128]

Bottom line is neck turning makes neck tension to release the bullet consistant, so does annealing. That's kind of what precision shooting is about, can you shoot 1/2 minute without it? Yes, but you're not going to shoot 1/4 minute & less.

 

[Heavies]

Thank you all for the replies and comments. I think I will continue to clean up the necks, if not for anything else, for more consistent necks/tension. It makes sense that the more even the brass is the better it can perform. Also the peace of mind that I am doing all that is possible for consistent accurate ammo.

 

[6BRinNZ]

Heavies - would you mind providing more detail as to how the process works...do the guys use different size mandrels...do they oversize slightly and then expand backout? I am quite interested as it makes a lot of sense and 6BR brass you have to put through an expander anyways.

FWIW I skim my lapua brass and anneal it every firing. I do it for consistencies sake...its weird how a load can look ok at 900 and go to 1000 and every little thing shows up...

TIA

 

[Heavies]

Not a problem. I saw this article on the euro champ FTR. who uses this method.
http://www.accurateshooter.com/featured/gunweek0104/

As well as other mentioning, I'm sorry but I don't remember where.

I use some thing with the same principal. The Lee Collet Neck Die. (start flaming ;D )

It seems to me, to be the most ideal way to size the neck of the brass with the minimal amount of working. You don't size it more than needed, you get zero or close to zero run out.
However, the cheap nature of these dies mean that one must polish and de burr the interior to prevent marring of the neck. I use a Redding body die for the sizing of the case. A two part full sizing.

Also, one other draw back is that one cannot 'play' with various neck tension without permanent modification or purchase of larger mandrels.

However, the method mentioned in the article above seems to hold the same neck tension draw back, and also an few additional draw back. How does one know that pressing the sizing mandrel trough the neck will not cause runout issues, and the need to clean out lube from the neck.

 

[6BRinNZ]

Thanks Heavies.