Precision Expander Mandrels from 21st Century Shooting
You can benefit from these precision mandrels, trust us…
Controlling cartridge neck tension is a critical aspect of accurate reloading. A very small change in the amount of grip on the bullet can actually have a noticeable effect on accuracy (and group size). You can tune neck tension with different size bushings used with FL-sizing or neck-sizing dies. You can also adjust neck “grip” by annealing your brass, or turning your necks for reduced neck-wall thickness.
But perhaps the most precise way to tune neck grip on the bullet is to use Precision Expander Mandrels. Many top shooters size their case necks down pretty far with a full-length sizing die then use a precision neck mandrel as a final step. This expands the neck back to the precisely-desired neck diameter. Because you are working from the “inside out”, variances in neck-wall thickness become less important. This also ensures you have a perfectly-round internal neck geometry for seating your bullet. (Yes, unfortunately some neck bushings are not perfectly round inside.)
For guys who want ultra-precise control over neck tension (and “grip” on the bullet), 21st Century Shooting now offers Precision Expander Mandrels in .0005 (one-half thousandth) increments. These will be available for most popular match calibers including: .224, 6mm, .25, 6.5mm, .270, 7mm, .308, and .338 calibers. These mandrels cost $17.99 each, or you can get a complete set of nine mandrels in .0005 increments (for one caliber) for $144.99. Listed below are the nine 6mm mandrels:
John Perkins, owner of 21st Century tells us: “Finally! We have our expander mandrels up and ready to order on our website here: http://www.xxicsi.com/expander-mandrels.html.” This is a big deal. James Crofts, past National F-TR Champion, says “WooHoo — great news!”
To get best results with these precision mandrels, John recommends using the 21st Century Expander Die Body, part #904. Watch video for set-up tips:
John adds: “We are still in the midst of turning all of these so some calibers will ship when they are completed. Should have them all done by end of next week or so! Thanks for your patience while we got these set up and in process!”
