
Availability: In Stock
The Lee Precision .257 Roberts & .257 Ackley Imp. collet neck sizing die delivers neck-only sizing without the need for case lube—a significant advantage if you're working with either the classic .257 Roberts or the hotter .257 Ackley Improved. Instead of a traditional full-length sizer, this die uses a collet that squeezes the case neck against a precision mandrel, producing a tight, concentric fit with minimal run-out. For handloaders focused on accuracy and brass longevity, that's a meaningful step up in consistency shot to shot.
Collet sizing is gentler on case necks than conventional dies, which means your brass lasts considerably longer. Since you're not working with lubed cases, setup is faster and cleanup is easier—no sticky lube residue to deal with. This die handles the sizing task only, so you'll need a separate full-length die or body die if you require full-length sizing for any reason, such as when switching between rifles or working with once-fired brass from unfamiliar sources.
Whether you're loading match-grade ammo for a varmint rifle or precision hunting rounds, the collet method produces ammunition with the kind of neck concentricity that tight-tolerance chambers reward. The initial investment in a collet die setup pays dividends through extended case life and tighter velocity spreads—both things that show up in your groups at the range.
| Brand | Lee Precision |
| Cartridge | .257 Roberts & .257 Ackley Improved |
| Die Type | Collet Neck Sizing Die |
| Quantity | Die Only |
A collet die uses a spring-loaded collet to squeeze the case neck against a precision mandrel. This method produces tighter, more concentric sizing with less run-out than a conventional sizer plug, and it does so without requiring case lube—saving you time and mess during reloading.
Yes. This single die sizes necks for both cartridges.
This is a neck-sizing die only. For full-length sizing—or if you need to size cases that have been fired in a different rifle—you'll want to add a separate full-length or body die to your press setup.
Collet sizing produces less run-out and is gentler on case necks, which extends brass life significantly. You also skip the step of lubing cases, making the reloading cycle faster and cleaner. If accuracy and brass longevity are priorities, the collet method pays for itself through extended case life.

SKU: 197557239 • Weight: 0.45oz





Availability: In Stock
The Lee Precision .257 Roberts & .257 Ackley Imp. collet neck sizing die delivers neck-only sizing without the need for case lube—a significant advantage if you're working with either the classic .257 Roberts or the hotter .257 Ackley Improved. Instead of a traditional full-length sizer, this die uses a collet that squeezes the case neck against a precision mandrel, producing a tight, concentric fit with minimal run-out. For handloaders focused on accuracy and brass longevity, that's a meaningful step up in consistency shot to shot.
Collet sizing is gentler on case necks than conventional dies, which means your brass lasts considerably longer. Since you're not working with lubed cases, setup is faster and cleanup is easier—no sticky lube residue to deal with. This die handles the sizing task only, so you'll need a separate full-length die or body die if you require full-length sizing for any reason, such as when switching between rifles or working with once-fired brass from unfamiliar sources.
Whether you're loading match-grade ammo for a varmint rifle or precision hunting rounds, the collet method produces ammunition with the kind of neck concentricity that tight-tolerance chambers reward. The initial investment in a collet die setup pays dividends through extended case life and tighter velocity spreads—both things that show up in your groups at the range.
| Brand | Lee Precision |
| Cartridge | .257 Roberts & .257 Ackley Improved |
| Die Type | Collet Neck Sizing Die |
| Quantity | Die Only |
A collet die uses a spring-loaded collet to squeeze the case neck against a precision mandrel. This method produces tighter, more concentric sizing with less run-out than a conventional sizer plug, and it does so without requiring case lube—saving you time and mess during reloading.
Yes. This single die sizes necks for both cartridges.
This is a neck-sizing die only. For full-length sizing—or if you need to size cases that have been fired in a different rifle—you'll want to add a separate full-length or body die to your press setup.
Collet sizing produces less run-out and is gentler on case necks, which extends brass life significantly. You also skip the step of lubing cases, making the reloading cycle faster and cleaner. If accuracy and brass longevity are priorities, the collet method pays for itself through extended case life.
SKU: 197557239 • Weight: 0.45oz
