Changing Calibers

Education for Changing Calibers

In general, when you are changing your Dillon loader to load a different cartridge, you will need at minimum a die set and a caliber conversion kit. The die set consists of the threaded tooling that performs actions to your cartridge cases. These actions include resizing the fired case, pushing out the fired primer, seating the bullet into the case, and crimping the case mouth on the loaded cartridge. The caliber conversion kit includes the shellplate that holds the case rims, brass locator pins that hold the cases in the shellplate during the reloading process, the powder funnel that the case pushes upward on to activate the powder measure and sometimes flare the case mouth, as well as any adapters needed on machines that feed the empty case into the shellplate. The Square Deal B loader is an exception, as the conversion kit for this machine includes the proprietary dies used only on the Square Deal B loader.

In addition to the die set and conversion kit, if you desire to leave your dies preset and adjusted for faster caliber exchanges, then you want to add a toolhead and a powder measure die to your setup. Should you also prefer to save more time by dedicating a powder measure to that setup, the DIllon Quick Change kit consists of the powder measure, powder die, toolhead and a toolhead stand. This has a cost savings as a kit over purchasing each component separately.

If your loader has an electric case feeder, you might require a different case feed plate. There are only five sizes of case feed plates, so it may not be necessary to get one.

Most Dillon loaders include the parts to convert your primer feed between the two sizes.  Many customers choose to add a second primer feed system set up so they have primer systems in both large and small primer sizes, so no disassembly of the primer feed is required when changing primer sizes.

Caliber Conversion Kits

The Caliber Conversion Kit is separate from the die set, but just as necessary. This kit consists of the shellplate, which holds the cases against the top of the ram, the powder funnel, which is a floating cylinder the case pushes upward on to activate the powder measure, and the brass locator pins, which are lifted out to give you access to a case in any station of the loader. If the loader has a case feed system, the conversion kit will also include any case feed adapters. 

The exception to this is the Square Deal B loader. This loader uses proprietary drop-in insert dies, and these dies are included in the conversion kit. 


The die set is separate from the caliber conversion kit. The die set consists of two or more pieces of precision tooling which thread into the toolhead in the top of the machine frame.  These dies, regardless of the manufacturer, share an industry standard 7/8-14 thread. The first die resizes the case and pushes out the spent primer. A second die seats the bullet into the case. If there is a third die, it crimps the case mouth separately. Some non-Dillon die sets may include an expander die. It is not necessary to use this die on Dillon equipment, as the Dillon powder measure performs this action. Dies are typically sold as sets, and some are available individually. For bottleneck rifle cases, the Dillon size dies incorporate a built-in stuck case remover. If a fired bottleneck case is inadequately lubed on the outside, the case will get stuck inside the size die. 

The exception to this is the Square Deal B loader. This loader uses proprietary drop-in insert dies, and the dies are included in the conversion kit.


Quick Change

One significant design feature of all Dillon loaders is that the dies thread into a quick-detachable block or plate called the toolhead. This means that once your dies are set up and adjusted, when you change out the toolhead, the dies and powder measure remain pre-set and adjusted. This significantly shortens the time needed to change calibers. The Quick Change includes the non-caliber specific parts needed to swap out the dies and powder measure. It consists of the complete powder measure, the powder measure die, the toolhead, and a stand upon which to store it when not in use. 

Casefeed Plates

There are five sizes of case feed plates available for the electric case feeder. The small pistol plate  is for 32ACP up through 10mm and 40 S&W. The large pistol plate is for 38 Special / 357 up through 50 AE. The small rifle plate is for 17 Remington through 223, 6.5 Grendel and 6.8 SPC. The large rifle plate is for 22-250 up through the standard belted magnum cartridges. The magnum rifle plate is a modified large rifle plate. It is for use with 45-70, the WSM and RUM cartridge families, the largest Weatherby cartridges along with cartridges based on 404 Jefferies and 416 Rigby, including 338 Lapua, 300 and 338 Norma Magnum.

 If you have an RL550 Case Feeder, you will need a caliber conversion kit in addition to a different casefeed plate when changing calibers.

Powder Systems

The Powder Measure System is a case-activated, adjustable dispenser. You must use a powder scale to calibrate the measure for how much powder it dispenses in each throw.  Many users prefer to dedicate a separate powder measure to each cartridge they load, to reduce the setup time. You can also purchase a Quick Change, which also includes the toolhead and stand.

Priming Systems

Most Dillon loaders include the parts required to change the primer feed between large and small primer sizes.  The industrial machines do not.  For some users, it can be very convenient to have a separate priming system for their loader. This eliminates the time needed to swap out the alternate primer feed parts.

Caliber Changing Accessories

There are a variety of accessories that make caliber changing easier. For bottleneck cartridges, a headspace case gage makes adjusting the size die precise and efficient. Toolhead stands allow you to store toolheads in a way to protect the depriming pin from damage and prevent powder spills. Dust covers for your quick change reduce powder contamination and corrosion. 


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