Working with Presses and Dies
• Mount your press firmly.  Any wiggle in the press can translate to variability in loaded ammo.  Portable presses are OK and can be used for many calibers, but if you’re working tough cases for long-range accuracy that require significant torque on the press, ensure there is zero wiggle room.

• For proper alignment and mating, always purchase a matched set of dies and shellholders from the same manufacturer.  While you can often use dies and shellholders from many different manufacturers on the same press, be sure that they are a matched pair. Use RCBS shellholders with RCBS dies – and the same goes for Hornady, Lee, Lyman, etc.

• There’s no such thing as a Universal Shell Holder!  If you’re having problems with de-priming, bullet seating, crimp consistency – or if things just don’t feel right – double-check to ensure you have the right shell holder installed on the press.  It’s a great idea to remove the shellholder as you remove a die and double-check that match before inserting a new die.

• Expander dies have tapered or stepped inserts that are designed to produce results of different geometries. Traditional tapered expander dies produce a “belling” of the case and stepped expander dies produce a carved inset for the bullet (and can also be adjusted for belling, if desired).  Tapered expanders and case belling may give the best results for inserting lead and other soft bullets.  Stepped dies provide for a more consistent seating of the bullet, more consistent impact on neck tension and less over-flaring.  Know which you’re working with to produce predicable results and measure your expander insert to insure the diameter is 0.002” smaller than the diameter bullet you will be seating for jacketed bullets and 0.003” smaller for lead bullets.

• Preparing your press for use includes cleaning, lubing and inspecting the press.  Follow the manufactures’ instructions, and just like your car, set a periodic press maintenance reminder in your reloading log book.
• Clean your dies – because when measuring to thousands of an inch, a lack of cleanliness can translate to a lack of accuracy.  Inspect the expander/decapping rod, neck sizing expander ball and bullet seating insert for galling.  Clean the die bodies.  Look for scratches in cases that are indicative of dirty dies.  And clean cases help to keep dies cleaner!

• Don’t crank down your expander/decapping rod!  Let it have some “play” and it will self-center.
• When using a separate decapping die, the decapping pin can often be removed from the sizing die – but only if neck expander ball isn’t included/needed (as with straight walled cartridges).

• Seating dies have separate seating plugs that conform to the bullet shape (round tip, flat tip, etc.) as well as ogive for the most consistent seating and to prevent damage to the bullet during seating.  If you don’t have the right seating plug to match bullet geometry, the correct plug can often be ordered from the die manufacturer.

• Seater dies also have integrated crimping for roll crimp or taper crimp (die is marked TC).  Roll crimping should only be used with bullets that have a crimping cannelure.  Taper crimping is appropriate for semi-auto calibers that headspace on the case mouth, such as the .45 Auto.  Those that desire a factory crimp can forgo the crimping function of the seater die and use a separate crimp die.