Home Forums Reloading Big Game Rifles Question about neck turning brass....

If neck turning brass, do you do it before resizing while the neck is expanded from firing the cartridge, or after resizing it in the die?

Resize it first is generally the way it's done. Depending on your neck turning tool--some use a pilot, some don't--it might require the neck is sized first. That applies whether you're inside or outside turning.

Unless you have a minimum spec chamber with the neck reamed small, why are you asking?

My Forster requires outside turning before sizing. If not the pilot won't fit inside. I set it up so I only kiss the thin side and take of the other,giving it more concentricity. I have two lots of .06 brass. Remington and Federal. Most of the Remington has been outside neck turned. In all truthfulness,I have seen no increase in accuracy in my Model 70. It gave me something to do when it is blowing snow outside. I doubt that any of the line manufactured sporting firearms will not see a benefit in turning.

IMHO, outside turning and then inside reaming is going to reduce neck tension to a degree that makes ammo for hunting purposes a little too vulnerable for the typical rough handling

The equipment I use requires sizing first w/o expander ball. The necks are then pushed over an expansion mandrel sized so the expanded necks are a close slip fit on the slightly smaller mandrel in the turner.

Sized first. I have a RCBS unit that simultaneously turns and reams. With the neck going between two cutting surfaces at once, it generates a very consistent product.

I neck turn on a lathe with a bullet-diameter mandrel; that process requires sizing first. Other processes are different of course.

Me either, in hunting rifles or even in custom bbls in hunting rifles. I gave up the idea a long time ago.



I've seen bullets in the mag pushed into the case from recoil when the necks were turned, or when not sized enough when guys were chasing accuracy.

I had to outside neck turn when I had a ton of .308 brass and turned it into .243 brass.
That was a lot of work, probably won’t do that again.

I wouldn't neck turn unless you use a bushing die other wise there's no way to control neck tension.

Some broad statements are being made about neck tension problems after turning that are not universally true. For example, if you're loading for 308 Winchester and using anything but thin WW brass your typical FL size die will most likely work better with necks that have been thinned a thousandth or two. OTOH, an RCBS FL die I have for 260 Rem happens to be nearly perfect for the brass I've been using. During sizing the expander ball barely kisses the inside of the neck on its way out. In that situation turning necks thinner would cause a problem.

You just have to have a handle on how the brass and dies you're using work together.

Pull the expander ball out of the typical FL sizer and you'll find your neck being squeezed down 8-10 thou at least, from fired diameter. The ball pulls it back out to a larger diameter There is usually more than enough to compensate for a couple thou taken off by neck turning. In fact, turning will make the brass last longer because it's being worked less each cycle. Most FL dies are pretty tough on brass.

I don't believe so. The cycle is the difference between fired OD as determined by the chamber and sized OD as determined by the neck section of the die. A thinner piece of brass interacting with the expander ball just shifts some of the cycle away from the expanding portion onto the firing portion of the trip.

I mentioned the thinner brass often working better viewed from a straightness/concentricity viewpoint.

It is all about concentricity and neck tension. I do not have a bench rest rifle, so the only time I turn the necks is to clean up neck thickness difference--i.e. one side of case neck is .011 thick the other is say .013. I also like to use the bushing dies to set my neck tension. I usually like about .002. Just for numbers, outside neck diameter is .268, insert bullet and now neck diameter is .270.

You could also accomplish the same thing by sorting brass by neck thickness if you have enough to sort from. When I turn necks I try to have the neck thickness vary no more than a .001. Some peope may say that is still too much, but for a hunting rifle or just a range rifle that works for me.

I have saw though where a .001 or .002 difference in neck tension will open or close a group. Concentricity and neck tension go hand in hand. That is why I like the bushing/bump dies.

Concentricity is the deal for me too. I don't have any tight neck chambers, but I do have rifles that will show the benefits of straight cartridges which are easier to assemble in cases with uniform necks.

I was turning the uneven necks of some Lapua 308 brass yesterday. Yes, Lapua with uneven necks. They were .016" thick on one side and .014" thick on the other. Cleaned up to .014" they're still plenty thick to work with off the shelf dies.

^^^I agree...

This may also be helpful to OP:
http://www.accurateshooter.com/technical-articles/reloading/complete-precision-case-prep/

I turned necks when I shot HP. 308..I could not tell the difference in scores to justify the time put into turning. You COULD say that HP dosen`t require the exacting accuracy as say BR does, so maybe the point is moot to begin with.
I have also turned or cleaned up some necks on Rem. brass used for hunting,,didn`t find that of much use either. YMMV

How good/bad were the necks to begin with?

By neck turning, I took .25" off of my 100 yd group using my custom 243. It reduced my group in my factory savage 30 06 a bit as well. Uniform neck tension will only help groups. I was turning the outside of the neck. Lapua brass in the 243, Nosler brass in the 06. Most people take too much off, thinning the wall right from the start. It doesn't take much to uniform the necks. Usually some is trimmed on one side, and not the other.Surprisingly, even lapua brass is not completely uniform, and takes some trimming as well. Not much, but a little.

I guess the way I look at it the smaller OD due to neck turning results in a larger ID after it is sized down and before it goes back over the expander in a standard FL die depending on amount of material removed. In my mind that expander will move less metal as it comes back through, thus "working" the brass less. Due to difference in springback, your final ID and thus neck tension may not be the same as before. But in my experience, most of my FL size dies go way beyond what is needed when sizing brass down, most likely so that they will work with all the different brass available. For instance, working with a 22BR now and the Redding FL die I have has a neck diameter of .240 and the Forster about .242. The bushing I need for the Type S neck and FL sizers for proper tension with uncut brass is .250/249". So the necks get way oversized than really needed and then pulled back out by the expander ball. That .010" sizing difference each time is much greater than the case to chamber neck difference for growth during firing and has a larger influence on case life in my opinion.

You're right about that one step, but the complete sizing & firing cycle works the brass the same amount regardless if the necks are turned or not. Maximum neck OD is determined by the chamber, and minimum neck OD is determined by the sizing die.

You can end up working brass less, IF you also have a tight chamber neck. 6mm PPC in benchrest rifles is a common example, where necks often have to be turned to fit the chamber, and total neck diameter change through the whole cycle may be only a few thousandths. But, neck turning in that case is just a tool to fit the brass to the chamber; it does not result in less brass working in and of itself.