Brownells 75th Anniversary - A Shooting Heritage

Step-By-Step Reloading Part 8: Seating Primers

Step-By-Step Reloading Part 8: Seating Primers

Sinclair Priming Tool with Primers & Cases
Back in June, we looked at primer pocket uniforming as a crucial step in brass preparation, part of this on-going series covering the steps of reloading. Along the way, we’ve also explored choosing the right cases, deburring the flash holes, trimming the cases and lubricating them, then sizing them. Now it’s time to reap the benefits of our careful primer pocket uniforming, as we seat primers into our cases. There are at least three different kinds of primer seating tools you can use, and each of them offers specific benefits and challenges.

Hand Priming Tools

Priming a case with a hand priming tool
Many precision reloaders really prefer to use hand priming tools. The biggest reason folks turn to high-quality implements like the Sinclair Priming Tool (#749-007-603) is the superior "feel" they provide. When you use them, you can actually feel when the primer enters the pocket and when it bottoms out. This extreme sensitivity helps you achieve a high level of consistency in primer seating depth - and consistency is one of the biggest factors in loading ammo for precision shooting. (If you want to know a whole lot more about this tool, read our Illustrated Guide To The Sinclair Priming Tool.)

The Sinclair Priming Tool holds only one primer at a time, which helps make it a high-precision tool, but not necessarily fast to use. One way to speed up the process a little, but still get a fairly high level of precision, is to use a hand primer with a primer tray, like the RCBS Universal Hand Priming Tool (#100-010-299) or the Lee Auto Prime Hand Priming Tool (#749-002-612). This style tool allows you to put 100+ primers into a tray that automatically orients them right side up and feeds them into the tool, but you can still verify that each and every primer seats exactly like you want it.

Bench-Mounted Priming Tools

RCBS Auto Priming Tool
Bench-mounted priming tools give pretty good “feel” for primer seating, but offer the benefit of extra leverage for almost-effortless priming. If you’re priming so many cases that you could wear out your fingers with a hand tool, a bench-mounted tool might be the way to go. Another plus is that once it’s attached to your bench, it’s not going anywhere. It’s very difficult to misplace or lose a bench-mounted priming tool!

One popular model of bench-mounted tool is the Forster Co-Ax Primer Seater (#749-006-946). It gives very good feel along with fast operation. Another is the RCBS Auto Priming Tool (#749-007-452). These tools use primer feed-tubes that allow you to load up many primers at once, and then continuously cycle cases through. Bench-mounted tools give you greater priming speed and volume, but they still retain most of the “feel” of hand tools.

Press-Mounted Priming Tools

RCBS Auto Prime
A press-mounted priming tool attaches directly to your reloading press. There are many types of these priming tools, and they can help to really speed up the reloading process. RCBS offers the Auto Prime (#100-010-234) attachment for its popular Rock Chucker Supreme press (#749-007-994). This attachment lets you quickly prime cases right in your press, feeding from a primer tube.

The place where press-mounted priming tools really shine is on a multi-stage or progressive press. Most progressive presses have some sort of automatic priming system built in. All you have to do is load up the tube with primers, and you’re off. One popular press that has a priming option is the Redding T-7 Turret Reloading Press (#749-008-321).

While press-mounted priming tools offer high speed, they’re lacking in the “feel” department. Many times, the priming stroke is incorporated into the same lever stroke that operates the entire press. With all that extra leverage, it’s just not possible to get the same sensitivity that a hand tool or bench-mounted tool gives. Press-mounted priming tools are great for high-volume reloading, like making handgun ammo.

Indispensable Accessories

RCBS Primer Flipper Tray
No matter which method best suits your reloading style, there are a few accessories you’ll want to add to help you handle primers effectively. Primer flip trays (#749-000-903) are a must. They’ll help you orient primers the same direction with just a little gentle shaking, and can also serve as storage boxes for them. Primer strips are another great way to keep smaller numbers of primers handy for use. If you plan to store your handloads for long term, a primer sealer (#105-000-110) is a great way to ensure they’ll ignite reliably, no matter what kind of weather or conditions they are subjected to.

A primed case
Primer seating is the very first step in reintroducing components into a brass case. There are many tools to choose from, depending on your reloading goals and needs. The next step in the process is adding powder to the case. We’ll look at that in detail next month.

Roy Hill
Brownells/Sinclair Copywriter