Discussion in 'Reloading' started by PHOENIX PHIL, Sep 18, 2017.
Yeah, 450-400 NE.
Phil, What I do on my brass for hunting is to turn the neck until it is even and concentric. Adjust the tool until you just get a shine right around the neck and up to the shoulder. Be careful at the shoulder and this is best achieved by trimming all cases to same length first and then adjust the tool a little at a time and inspect under a magnifying glass to determine when the shoulder is met. Neck turning is one off and to me it reduces one more variable with reloading.
For my longrange rifle I turn the neck to a set dimenson because it has a tight neck chamber and I use a insert in the neck die to give the bullet a certain amount of grip in the case neck.
I've always thought that neck turning was required only by bench rest shooters in bench rest rifles. Concentricity or lack thereof is the major reason for fliers out of hunting rifles. Hornady's Lock and Load Concentricity Gage is inexpensive and easy to use. Another trick I picked up recently is to just barely seat the bullet into the case and then rotate it as you bump the bullet to the required seating depth.
lol - I started doing that 40 years ago and I thought I was the only one doing it!
I have no idea if there is any practical value...but it makes me feel better!
Good to meet another brother afflicted by ballistic OCD.
If I was really worthy of the title, I would have dug out the text for my experimental design class to design an experiment to test for effects of the various methods.
Alas, I am a slacker and just blindly do what I've been doing since Gerald Ford was President.
I am not worthy....
LOL, oh lord that's funny. I haven't done a DOE either. Just try to vary one variable at a time and compare to baseline.
I do too! Always wondered if it was truly necessary or if I was just told to do that by a guy that was told to do that.
How about we just call it "Ancient Wisdom"?
Back to the subject of neck turning and the case for why to do it......at least in my mind.
Presume first there is some variance in the neck thickness of your brass. Also presume that your rifle is perfectly concentrical at the neck part of the chamber. Now if the result of running the brass thru the sizing die is also a perfectly concentrical inside neck, then there must be something of a "bulge" on the outside of the neck.
Now if all of these presumptions are true, I would have to think that when a round is fed into the chamber there would be an unevenness in the contact the neck makes with the chamber. This in turn I would think would cause a small amount of canting of the bullet with respect to how it's lined up to lands of the barrel. From round to round there would be variance in this "bulge" and where it was located as the round enters the chamber. As such then there would be variance in POI as those rounds are fired.
By turning the necks, you remove the bulge and create more consistent contact in the chamber from round to round and with that less variance in POI.
Have I got a clue here, or am I way out if left field?
You have a clue!
And your explanation also shows why I believe outside neck turning is the way to go, and not inside. I think it is also easier to control the cutting process. You do need to be very careful not to cut below the junction of the neck and shoulder!
The other reason to turn necks was alluded to in my earlier post. Target types have their necks cut purposefully tight so that neck turning is essential to get ammo fit. Kind like starting with a piece of wood larger than needed, and trimming to perfect fit.
There is another, more theoretical, benefit.
Even neck tension all the way around the bullet. How you measure that benefit, I don't know. But we do know that eliminating variation from round to round can only help.
There is another reason to neck turn, and that is to prepare the cases for the neck sizing die, which at this level of process is made available in increments of 1 thou, so you need to control for the actual fired size of you ammo of a given wall thickness.
I went into all this stuff with a particularly fine Sako .222 I owned, this was back when you couldn't get a composite stock in a factory rifle, well before there were .5" guarantees. I found neck turning and all that other jazz were worth it on paper, but I could get real .5 inch groups of 5 shots without that jazz. In the end, what put me off was that I preferred to buy brass that was nickle plated because it was so easy to clean, and it was a pain to turn, and then got dirty and was hard to clean.
I also used the turn the neck till the brass is clean method, but I would also do a partial neck turn. Some of the brass I was using got too thin when I turned all the way around, so I would do about 3/4. I never had brass that was hi low, hi low, it always came down in continuous cuts until I got the whole neck. But on some of the cases I didn't go all the way.
Of course if you have cases like that you should be tossing them for precision work, but they were still OK for what I was doing. So neck turning teaches you a lot about brass, not just egocentricity, but you get a feel for how it cuts, how hard it is, and so on.
That tool looks basically like my Neil Jones tool, just more complicated looking. At the end of the day, if you live where there are good resale markets, owning an actuall lathe gets you further than all this jazz, except I suppose it is a trap all it's own.
As far as the concentric bullet seating is concerned, I always buy in line gear. The first unit I bought was a Wilson chamber die, but it used a press, and was sort of slow. I moved away from the hand tools and got a Neil Jones 7/8" neck die with floating precision collets, and a Bonanza in line bullet seating die, of which there are many types at the moment. Basically that sped the whole process up, was cheap as far as the seating die was concerned, and I couldn't tell the difference on paper. For hunting purposes you can get much the same results with die sets around 50 US.
You often see upgraded sets called bench rest dies, and they have micrometer turrets on them. These are nice if you find them at a good price, but the gold standard Wilson hand dies don't have that, just grub screw adjusters, I think. The key point is that the bullet and case are aligned through the stroke.
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