21st Century TiN Neck Turning Expander Mandrel


Select the calibre of the expander mandrels here…



21st Century TiN Neck Turning Expander Mandrel (used in conjunction with 21st century Outside Neck Turn mandrels)

Please Note: These expander mandrels may not work ideally for special bullet grip expanding. These expanders are meant to match the size of Outside Neck Turn mandrels and are under the caliber size. For bullet grip expanding there is a special range made for these tasks. See 21st Century undersize expanders where there is a range of sizes in half thou (0.0005″) increments.

  • These are the 21st Century Expander mandrels used as a preparation tool prior to outside neck turning cases. Expanding up the inside of the virgin brass.
  • Titanium Nitride coating
  • Fits into both the STD press adapter or Long adapter from 21st century Shooting
  • These are identified with engraving of the Prefix “E” and then the calibre. These mandrels will NOT fit (nor meant to) into the 21st century neck turner body.

Tip #1: If deciding to outside neck turn your cases which have already been fired, there will need to be special preparation of those case necks to achieve proper outside neck turning.
Usually the best and the simplest way is to use a regular full length resizing die (non bushing) and temporarily remove the decapping rod and its exapnder for that die. Just use the die body, Bump the shoulder -0.002″ as usual, then lube inside of the necks and finally use this 21st century expander system to prepare for Outside turning.
If you attempt this task using a neck bushing type die you will most likely end up making the brass too thin at the Neck/Shoulder junction area because a neck size bushing in a die cannot resize all the way down to the shoulder junction. So, think about it. An important safety tip!

Tip #2: These expander system may or may not suit for a different task. Which is internal neck expanding after resizing the cases in a neck bushing die (when those cartridges have NOT been outside neck turned). This is to even out the insides prior to bullet seating.
The size of these expander mandrels is approx 0.001″ less than calibre (bullet) size. Also, as it happens, 21st Century neck turn arbors will fit the same two press adapters and they are -0.002″ less than calibre (bullet) diameter.


(17 cal, 20 cal, 22 cal, 6 mm, 25 cal, 6.5 mm, 270, 7 mm, 30 cal, 33cal)