Mark 7 Apex 10 Autodrive DecapSense

Decap pins break. The DecapSense from Mark 7 catches the issue before there’s any further damage!


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In the Series

This video covering the Apex 10 DecapSense is a continuation of our series with guest John Vlieger of Mark 7 reloading. 

We’ve covered priming adjustments, powder measure adjustments, caliber conversions, and machine maintenance

About the DecapSense

The DecapSense exists to stop the Mark 7 Apex 10 when it doesn’t detect a spent primer.

From Mark 7 Reloading

Sometimes you decap and sometimes you don’t. (Decapping is the process in Station #2 that pushes out the old primer.) What happens when your decapping pin is broken and you don’t realize it? How about that stubborn spent primer that hangs onto the pin and isn’t fully discarded, only to be pushed back in by the swage station? Oops.

This is a must-have accessory for your Mark 7 Press. The positive decap sensor uses optical recognition to determine if a spent primer is removed, and if no spent primer falls the machine stops after the stroke, making it easy to remove the impacted case. Save yourself and save your machine. If you are processing or loading new brass, simply disable the sensor from the Mark 7® tablet interface. The DecapSense™ ALSO acts as a brass sensor – when enabled it can stop the press when brass is not present in the decapping station.

A critical safety and productivity measure, this sensor can dramatically reduce injuries, downtime and machine breakage. Ships with the sensor assembly, hardware, and clear tubing.

What’s In the Box

The DecapSense arrives alone in a small cardboard box.

Installation and Test

Installation of the DecapSense is very simple. Remove the factory decap chute with the two 9/64 bolts, install the Decap Sense, and plug it in.

You may also have to do a unit power cycle for it to recognize the sensor. Turn the console off and back on to do this. 

Testing is easy. We started with a fired case (with spent primer intact) and a brand new, unprimed case in the case feed.

Once in position, we enabled the DecapSense and let the machine run twice.

The first pass kicked out the first dead primer. The second pass stopped the machine, triggering a “no ejected primer detected” message on the console.  The sensor is “looking” for something falling past it during the window at the bottom of the stroke. If it doesn’t “see” anything, it stops the machine. 

To fix it, select ok and end cycle. The toolhead will finish the stroke. You can then grab the case in question for inspection and turn the sensor on and off at will. 

Get the Gear 

The Mark 7 Apex 10 is available directly from Mark 7 as well as from the Double Alpha Academy

Find the Mark 7 DecapSense at!

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Gavin Gear


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