Neck Turning

[LynnJr]

Guys I was neck turning brass for my 50 BMG today and thought I would post some pictures of this easy but often times misunderstood part of reloading.
The steps to get really good results are quite simple.
Full length resize so the necks are at there longest length.
Chamfer at least the inside of the cases neck.
Lube the inside of the neck with Imperial Sizing Die Wax on a Q-tip.
Expand the necks using the mandrel. The mandrel fits the necks properly for turning. If the necks are too tight you would get excessive heat and galling. If too loose the cases will flop around on the turner giving an uneven neck thickness.
Turn the neck using a variable speed drill or by hand.
While the case is still chucked up you can chamfer it inside and out.
Next is to use a 3M Greg pad soaked in alcohol to finish polish the neck.
One mistake most new neckturners make is to let there turner to get hot. After each neck is turned drop your turner into a bowl of rubbing alcohol.
It sounds harder than it actually is.

[bsumoba]

Funny Lynn....I was turning brass today as well. I am turning 6.5x284 Lapua brass for my 284 Shehane. Since I had all my stuff out, I might as well show what I do as well:

Drill, Lee Case Holder and Shellplate for your particular brass, Ball Micrometer, PMA neck turning tool with 35 degree cutter edge, Carbide Turning Mandrel and corresponding expander die, and feeler gauges.



I first expand the brass with the expander mandrel using either sizing wax or any kind of lube on the inside of the neck. These are 25cal mandrels as an example, but I was using 7mm mandrels.



Chuck the brass onto the drill.

I set the depth of the mandrel to stop such that I am just starting to cut into the shoulder. This helps to also alleviate any potential donuts. I use feeler gauges to get close to my desired neck thickness. In this case, I am cutting to 0.014".



I will then run the brass into the carbide neck turning expander die. I will make adjustments to the PMA tool to get the desired thickness and measure with a ball micrometer. '



The result is a nicely turned piece of brass ready for loading. I will usually then run this through my FL resizing die and then clean in either a wet tumbler or dry tumbler.

Notice the cut is into the shoulder. This is on purpose and should only be done if you have an angled cutter that matches the shoulder angle of your brass. Otherwise, you will weaken the brass at the neck/shoulder junction because you will be cutting too deep into the shoulder.

[bubbala]

50 bmg is kind of cheating. try some lapua 223 and see how many cases you have to toss before you can set the knife to barely smooth out the unevenness.

[NiteQwill]

Honestly, I stopped neck turning because I never really noticed a difference in accuracy when compared to just sizing with a neck bushing only. Of course, this is among the same brass (Hornady, Lapua, for example).

[LynnJr]

Brian
Make sure you put your turner in alcohol or water after each neck is turned.

For some reason I can't see your pictures but get yourself some 3m grey scouring pads. Leave a piece in the rubbing alcohol and when your done turning wrap it around your case neck and spin it up.
You can compare this on one piece of brass to the way you are doing it now.
Pat at PMA Tool makes nice gear.

[J-cat]

Honestly, I stopped neck turning because I never really noticed a difference in accuracy when compared to just sizing with a neck bushing only. Of course, this is among the same brass (Hornady, Lapua, for example).

Same here.

Sorting by case weight keeps neck thickness pretty even.

Can't turn a factory Remmy into a .3 MOA gun by turning necks, not when the chamber is eccentric.

[bsumoba]

I just take off the high spots and turn as little as I can, usually getting about 80-95% cleanup. most of my setups are no neck turn reamers so I have a lot of neck clearance, but when I see .002" difference on some brass, to me it makes sense. You guys might not see it at 100 yards, but in F-Class at 1K or in benchrest, it could. I see a difference in more consistent neck tension, which results in better vertical at long distance. I also have a couple non-standard rounds that require neck ing up or fireforming and neck turning is usually required because the neck/shoulder junction gets a little thick, resulting in potential seating depth issues.

To each his own....

[J-cat]

If you sort your cases by weight there's not going to be a .002" neck thickness variance, and if there is it'll be around 2-3%.

If you take those 2-3% and turn the necks you just spent $100 on equipment to fix 3% of your components.

Then, when brass starts to flow, you're going to have a doughnut at the base of the neck which will require constant maintenance though neck turning and inside reaming.

I think a better route us to avoid all that through better cartridge choice aforethought.

[bsumoba]

I do sort my brass in 1gr increments. This partly is to help me mentally knowing that I am using brass that from a weight standpoint is more consistent. I do not sort by volume and I have not tested at distance, using a piece of brass that is let's say 3-4 grains different in weight to see how much different it shoots. It is not that much work for me to open 1-3 boxes of new brass and weight sort at the beginning and then shoot them in batches. I am using lapua brass, which is fairly consistent if you buy your brass within the same lot #. I usually get two batches, so brass is usually 2gr from the low to high with maybe 1-3 pieces of brass falling out of the group, which gets used for dummy rounds, fouling shots, etc. However, there is still a possibly of getting inconsistent neck thickness even with weight sorting. 0.002" difference is rare actually, and it is usually more like 0.0015-0.0005" typically. Remington brass has been known to have a much bigger difference. I have seen 0.003" difference in Remington 300 RUM brass.

Admittedly, I load my rounds long anyway so the donut is not a problem for me.

I'm not necessarily advocating to neck turn. I don't turn my 6.5 creedmoor brass at all because I am using this in a tactical rifle where turning brass seems like a pointless exercise as I lose the brass more often or I do not need the most absolute precision. 1/2" MOA long string groups is perfectly fine with me.

Hell, there are plenty of guys shooting national record groups and posting high master scores without neck turning. I partially do it because it is a mental thing for me. I do see some benefits in my rifle at long range distances and have seen more consistent seating pressure, better ES/SD, and as a result, better vertical results with turned brass than non-turned brass. And...the initial cost is high, but amortized over the life of shooting that caliber, it will becomes less and less every year.

As far as cartridge choices go, specifically for F-Open, there are plenty of choices out there that do well and have off-the-shelf brass for it. Problem is finding it usually or needing to form from another cartridge so you can use the brand of brass that is more consistent and/or easier to find. The straight 284 and 284 Shehane is hard to beat IMO. So far this year from what I have seen and read, the Berger SWN, Sac Valley Zins Palma and the Texas LR State have all been won with either the straight 284 or 284 Shehane. Almost everyone is using necked up Lapua 6.5x284 brass.

[CSACANNONEER]

Honestly, I stopped neck turning because I never really noticed a difference in accuracy when compared to just sizing with a neck bushing only. Of course, this is among the same brass (Hornady, Lapua, for example).

I've tried it and didn't notice any difference either. I do have standard 50BMG chambers instead of tight chambers so, the simple facts are that I don't have to neck turn to get my brass to fit my chamber and, I am not a good enough shooter to notice any difference in my guns.

[LynnJr]

Guys the straighter you start a bullet down the bore the more accurate that round will be.
This has nothing at all to do with case weight. Zero Nada zilch.
Most cases don't have a even wall thickness all the way around the neck. When you neck turn your brass it makes the bullet concentric with the brass and allows the shooter to determine how concentric his ammo is to his/her guns chamber. It also gives a more uniform seating depth and neck tension.
Another advantage comes from fixing mistakes made by the large manufacturers. If you have any of the WSSM chamberings you can't download them and not get erratic results because the necks are way too thick.

On a factory gun with the sloppy chamber and a heavy ejector your brass is already pressed off center of the bore by the enormous tolerances of a factory chamber. Thinning the necks further would only add to this tragic bit of machining.

CSACannoneer
The necks on the 50 BMG are some of the worst there are. I am shooting a 0.554 chamber with 0.551 necks giving me 0.003 worth of clearance. On some cases I get zero clean up at all while with others the tool is working overtime to cut off all that brass.

Brass doesn't flow foward but poor reloading practices make it look that way.

[J-cat]

When you turn necks it makes the OD of the neck eccentric in relation to the body. The reason for this is the mandrel indicates off the ID. Because the case thickness varies, the ID is always eccentric.

Case weight has to do with neck thickness. The heavier the case, the thicker the neck walls are. That's a fact. For the purposes of neck tension, sorting cases by weight accomplishes the same thing as neck turning.

Whether .002" of runout destroys accuracy is debatable. Most factory chambers are off by that amount so worrying about .002" is silly.

[NiteQwill]

Again, the fact of the matter is that I believe it is debatable. I'm still able to turn out sub 1/10 MOA rounds downrange with zero neck turning. Any more case prep is, in my experience, a waste of time taken away from trigger time.

I sort my brass by weight, neck size, load, shoot. My SD remains low and I spend more time shooting 1000+ yds than worrying about the concentricity of my neck.

YMMV

[CSACANNONEER]

CSACannoneer
The necks on the 50 BMG are some of the worst there are. I am shooting a 0.554 chamber with 0.551 necks giving me 0.003 worth of clearance. On some cases I get zero clean up at all while with others the tool is working overtime to cut off all that brass.

What brass are you using? I have 500 never fired, pulled down Israeli stuff I've been sitting on for a few years. It is far better than the LC stuff I've been using. I'm thinking about breaking into my TZZ stash this year but, it's hard for this cheap SOB to start shooting $2.50 a piece brass when I've got so much LC and Mitchel Mauser brass around and I've been doing so well with it the last few years.

[Mike402]

I'm still able to turn out sub 1/10 MOA rounds downrange with zero neck turning

Impressive, please post pics. Would love to see what sub .1 MOA groups look like, as I know I'll never shoot that accurately. That's pretty much world record benchrest-sized groups