Reloading Basics – Primer Pocket Uniforming | Top Rated Supplier of Firearm Reloading Equipment, Supplies, and Tools - Colt

Reloading Basics – Primer Pocket Uniforming

Primer pocket uniforming is one of many case preparation techniques that we perform and recommend to our customers each time they reload. Our Sinclair Primer Pocket Uniformers (UN-8001) cut the primer pocket depth to the correct SAAMI specifications and clean the carbon from the pocket after each firing.

First, it might help us to better understand what a primer consists of, and its primary function within a cartridge. This will help provide us some insight as to why we feel uniforming the pocket is so important. The primer is an explosive component which ignites the propellant (powder), forcing a bullet from the case and down the barrel. All primers consist of a cup, propellant explosive, and anvil. The firing pin strikes the cup, which forces the cup and compound against the anvil causing detonation.

Both variations in primer pocket depths, as well as inconsistent pressure applied to a primer during the seating operation, will alter primer depth and the effect of the firing pin blow. These inconsistencies may adversely affect ignition, which in turn, degrades accuracy. Our Sinclair Primer Pocket Uniformers (UN-8001) allow the handloader to cut each primer pocket to a uniform depth to improve your firearm’s ignition.

Our Sinclair Primer Pocket Uniformers (UN-8001) are ground from one solid piece of solid tungsten carbide and are machined to exacting tolerances – there’s no need to worry about changing the depth of cut. They’ll uniform the pockets to a consistent depth and also square the bottom in relationship to the case head.

All it takes is a few turns to uniform each primer pocket, either by hand in one of our comfortable handles (UN-8004), or use a power screwdriver adaptor (UN-8005) to speed up the process. After firing your cases, use a uniformer to clear carbon deposits too. This keeps the pocket clean and free of debris to improve your “feel” while seating a new primer. Removing the carbon takes a simple flip of the wrist – no power is necessary after the intial uniforming. Sinclair Primer Pocket Uniformers (UN-8001) are available for small pistol/rifle primer pockets, large rifle, large pistol, and for BMG primer pockets. Accessory handle and power screwdriver adaptor are available separately.