Chain Detonation — What Happens When A Primer Stack Blows

What can happen when the bottom-most primer in a primer feed tube goes off? A big bang, that’s what. Some or all of the primers in the vertical feeding tube can go off in a chain detonation. That’s exactly what happened to Dustin Ellermann, Top Shot Season 3 Champion. Scary experience, but thankfully Dustin was not injured. He writes: “Super thankful that I was wearing my Wiley X eye protection this weekend when I was reloading some .223 rounds. My press detonated nearly 100 small rifle primers. Shown here is the magazine feed tube. Not fun but it could have been much worse. Stay safe!”

When working with progressive reloading presses, you should definitely wear eye protection. Dustin’s chain detonation experience proves that — without a doubt. Remember you only have one set of eyes!

RCBS APS Strips — Alternative to Primer Tubes
When you stack a column of primers in a single metal tube, you’re asking for trouble. As Dustin Ellermann learned, when one primer fires, the entire column can follow suit in a chain detonation. Thankfully, you do have options when it comes to primer feeding on a progressive press. RCBS developed an innovative primer system for its Pro-2000 progressive press. Instead of being stored in a vertical tube, primers are placed in flat, plastic “APS” strips, with a ring of plastic separating each primer. Moving horizontally, primers are never stacked, so the chance of a chain detonation is reduced dramatically. The re-usable APS strips are color-coded for different primer types. You can buy CCI “pre-loaded” primer strips, or you can insert any brand of primers into strips using an RCBS strip-loader tool.

RCBS Pro-2000 with APS Strip Priming System

AccurateShooter.com Editor Uses Strip Primers
This Editor owns an RCBS Pro-2000 progressive press. The RCBS strip-priming system was one key reason I selected the RCBS Pro-2000 over similar-priced progressives from Dillon and Hornady. I believe the strip primer system is safer, more positive, and easier to use. Before I purchased my RCBS progressive, I “road-tested” the competition. I loaded hundreds of rounds on each of four different progressives: Dillon 550B, Dillon 650, Hornady Lock-N-Load, and RCBS 2000. I was concerned about the primer feed tubes on the Dillons, and I found the RCBS rotary powder measure was much more precise (and easier to adjust) than the sliding bar system on the Dillon machines. The RCBS priming system was definitely more fool-proof than the system on the Hornady press (a first-generation L-N-L that had issues with primer feeding). After “test-driving” blue, red, and green brand progressives extensively, I settled on the RCBS Pro-2000. A decade later, I still think I made the right choice. I like the APS strips for big jobs, and I can also use them in the RCBS hand-priming tool (shown below). With the strips, it’s easy to prime 20 or 40 cases at a time, and then switch to another type of primer for comparison testing.

The APS priming system also works with press-mounted priming tool, bench-mounted tool, and APS hand-tool. EdLongRange uses the press-mounted tool: “I also like the APS approach but use the press-mounted unit (saves your hands/wrists — and I haven’t had a need for a progressive press in over 20 years). Loading the primers in the strips is a bit of a PITA but very manageable. As with all tools there is a learning curve.” CLICK HERE for video showing strip-loading tool and press-mounted APS tool. The press-mounted tool is no longer in production, but you can still BUY IT HERE.