Our range of eight Brown & Sharpe-style Collets is one of the secrets to precise and repeatable case trimming. After all, if the case isn’t properly inserted and securely held in the case trimmer, any subsequent conditioning or bullet seating operation will not be accurate, no matter the quality of the tool or the experience of the operator.

  • The internal Collet steps ensure that the case head is firmly seated in the Collet, even when there is case rim diameter variation, unlike one-size-fits-all universal chuckheads or multi-piece shell holders.
  • The tapered design ensures that the Collet securely closes on the case rim without pulling the case back. When you lock a case into one of our Case Trimmers, it stays exactly where you put it.
  • All Collets may be purchased individually. Several common sizes may be ordered in kit form, along with a selection of Pilots, with the Original and Classic Case Trimmers Kits.

Collets #1 – #4 are designed for use only with Original and Power Case Trimmers. Note that they are not interchangeable with Classic Case Trimmer Collets.


  • Original Case Trimmers manufactured before June 1, 2010, required a Collet Housing enlargement to .610″ when using the #4 Collet; those manufactured after this date already have this modification.
  • #4 Collets manufactured after January 1, 2010, have two steps as shown above; those manufactured before this date have one step of .605″.
How to Order

We recommend first entering your caliber into the Cartridge Search to determine the Collet.

Measure your case diameter at its rim. Look for a corresponding step dimension in a standard Collet size (#1 – #4) above.

We also offer custom diameters within the size range of .275″ to .600″.

Weight 0.038 lbs


Inserting Case for Truest Alignment at YouTube.com
High-resolution Images