RCBS offers various ways to turn your necks and ensure ultimate precision during brass preparation and reloading. But first, what is neck turning? Why should you think about adding this operation to your reloading process?
Why Neck Turn
Brass leaving the ammunition factory doesn't always come perfectly even. To ensure that your case neck — the part that actually touches the bullet — is an even, consistent thickness, reloaders will "turn," or shave or peel the outside of their case necks with a cutting blade riding over a mandrel. This forces out any irregularities and brings the wall to one uniform thickness all the way around.
Why does an irregular neck thickness matter? A thicker wall on one side pushes the loaded bullet toward the thin side, so it sits at a slight angle and during firing, enters the rifling at that angle. Uneven walls also grip unevenly, so the bullet can release unevenly when the powder ignites — varying the pressure, muzzle velocity and results downrange.
Who Should Neck Turn
There is no doubt neck turning can add precision to your case prep process. That said, turning necks costs you time. Depending on where you are at in your reloading journey and why you are reloading, you will likely see a better return by focusing on aspects of the reloading process that are 1. Faster to do and 2. Deliver more bang for your buck, as measured in precision results downrange. Investing in quality equipment and spending time to dispense consistent charge weights, bullet seating depth, proper case re-sizing, utilizing a mandrel system for consistent neck tensions or annealing are all processes that match-winning shooters do almost universally.
Turning may be required by advanced handloaders who have the basics down, and those who are processing brass they formed themselves, brass fired in a tight-neck chamber, or necks that have been measured and found to be far out of spec.
Case Neck Turn Methods
If you are turning necks, RCBS offers equipment that can be installed on our manual Trim Pro series of trimmers for a faster turn, or a dedicated hand case neck turner tool for a piece by piece process.
For those turning cases by hand, the RCBS Hand Case Neck Turner zeroes the cutter to the pilot, so the cut references the inside of the neck — the surface the bullet actually touches — rather than the outside. It dials in half-thousandth increments, works left- or right-handed, and the pilot doubles as a case-mouth stop so the cut stays uniform over its full length. This tool needs a caliber-specific pilot, sold separately.
Prep First
Cases need to be sized, trimmed to length, and chamfered and deburred before you turn. Wipe off every trace of case lube — a slick case won't grip in the holder. And clamp cases by the body, never up near the shoulder or case mouth.
Assemble the Tool
Thread the brass lock ring about three-quarters of the way up the micrometer body. Slide the cutter spring over the cutter shaft and insert it into the bottom of the micrometer body, then thread the micrometer assembly in until about a quarter inch of the cutter is exposed, flat side up. Run the set screws in until they just touch the flat on the cutter shaft — the cutter should still slide freely. Install the pilot for your caliber and snug its set screw.
Working from the manual. The full assembly sequence, with photos of each step, is in the Hand Case Neck Turner product instructions.
Set Up the Case Holder
Pick your collet: the small collet grips 22 Hornet through 7.62x54R, and the large collet runs 30-06 Springfield up through the Weatherby and Lapua magnums. Drop the collet into the bottom of the case holder and secure it with the lock nut. Fit the two O-rings on the guide plug, install it into the bottom of the lock nut with the cupped end toward the collet, and thread the cap onto the holder.
Set the Length of the Cut
Slide a prepped case onto the pilot all the way to the stop and bring the cutter assembly down until it's just shy of touching the neck. Loosen the pilot's set screw and move the pilot in or out until the cutter's leading edge sits right where you want the cut to end, at the neck-shoulder junction. Lock it down.
Zero the Cutter
Take the case off, set the micrometer to zero-zero, and screw it down until the cutter contacts the pilot. Lock the micrometer body with the brass lock ring. You're zeroed.
Decide How Much to Take Off
How do you know what you should cut to? Two ways to find your number. With a ball micrometer, measure neck thickness at several points around the neck on five to ten cases from your lot — the smallest reading is your target. Or do the math from a loaded round: measure loaded neck diameter, subtract bullet diameter, divide by two. For example, in 6mm, a .269" loaded diameter minus a .243" bullet leaves .026", so half of that is .013" of neck wall. Set the micrometer to your number and lock the cutter.
Make the Cut
Loosen the cap enough to pass a case through the collet fingers, then tighten it to secure. Hold the tool in one hand and rotate the case clockwise with the other, feeding the neck over the pilot and into the cutter with steady forward pressure. (The tool is designed to rotate the case around the pilot, but you can hold the case still and rotate the cutter assembly around it if you prefer.)
The cutter works on both the forward and the back stroke, so don't cut all the way to the base of the neck and then yank the case off — keep rotating as you back it down off the pilot. If you need to remove more than a thousandth, don't take it all in one go; make two or more passes of a thousandth or less. A clean, bright band of fresh brass means a properly turned neck.
Checking Your Work + Common Errors
To verify your hand neck turn job was done correctly, the best way to be sure is to use a micrometer with a ball anvil reading to a ten-thousandth. The RCBS Vernier Ball Micrometer reads to .0001", and the ball anvil reaches inside the neck to measure wall thickness rather than outside diameter.
Common ways to turn incorrectly include:
- Cutting into the shoulder. It's easy to run the cutter too far, and thinning the neck-shoulder junction weakens the case right where it needs strength.
- Taking too much off. Over-thin walls buy chamber clearance you didn't want, which is associated with necks splitting sooner than they should.
Set your depth deliberately, cut a couple of sacrificial cases first, and measure before you commit a batch of good brass.
Turn necks. Shrink the variables.
Hand turner, caliber pilots, and trimmer-mounted turners are all in stock.
Always follow safe reloading practices. Consult current published load data and your equipment's instruction manuals before beginning any reloading operation.
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