Guide
Powder Check Systems Compared: Powder Cop vs. Lock-Out Die vs. Dillon vs. Laser
Every progressive reloader eventually asks the same question: how do I make sure every case that leaves my press has the right powder charge in it? A squib (undercharge or no charge) can lodge a bullet in your barrel; a double charge can wreck a gun and injure the shooter. Powder check systems exist to catch these errors before the round is finished — but the options range from a $45 die you have to watch, to laser systems that measure every charge and stop the press automatically. Here is how they actually compare, including where the cheap options are genuinely good enough.
Hornady Powder Cop (~$40–50): a visual indicator you have to watch
The Powder Cop is a die with a rod that rides on top of the powder column. As each charged case comes up, the rod rises; a marker shows whether the level looks right. It is simple, cheap, and reliable at what it does — but what it does is entirely passive. It will not beep, and it will not stop anything. If you look away at the wrong moment, the bad charge goes right through. On a manual press at modest speeds with an attentive operator, it's a reasonable minimum. On anything automated or fast, a check that depends on human attention is the first thing that fails.
RCBS Lock-Out Die (~$60–90): mechanical stop, pistol calibers only
The Lock-Out Die is the clever one of the mechanical bunch: if the charge is meaningfully high or low, the die physically locks the press mid-stroke. No attention required — the press just stops moving. The trade-offs are real, though. It works with straight-wall pistol cartridges, not bottleneck rifle cases. Getting it adjusted correctly is famously fiddly (decades of forum threads exist on setting it up), and like every probe-style device it occupies a die station and physically contacts the powder — which can mean disturbed charges and sensitivity to fine, dense powders and small charge weights.
Dillon Powder Check (~$99): an alarm, not a stop
Dillon's system for the XL650/750 and 1050/1100 uses a probe and sounds an audible alarm when the powder level is off. It's well made and integrates cleanly with Dillon toolheads. But note what it does: it beeps. It does not stop the press. At hand-cranked speeds that's usually enough — you hear it and stop. Under an autodrive at 1,500+ rounds per hour, several more rounds cycle before you react, and now you're digging through the output bin. It also occupies a station and needs the probe matched to the cartridge.
Mark 7 PowderCheck (~$200): integrated, probe-based, Autodrive required
Mark 7's own PowderCheck sensor drops a probe through over/under windows and reports to the Autodrive, which can stop the press — a genuine step up from alarm-only systems, at an attractive price if you're already in the Mark 7 ecosystem. Its limits: it requires the Mark 7 controller (it is not a standalone device), it is still a contact probe with the spill and probe-matching characteristics that come with that, and owners on the Brian Enos forums report false-alarm frustrations — notably tripping on empty stations during startup and shutdown runs — plus sparse documentation.
Laser measurement: what changes when nothing touches the case
RCM laser powder checks take a different approach: a laser measures the actual powder level in each case, without touching the case or the powder. That single change removes the entire failure family that probe systems share — powder spills, suction pulling powder from the case, probe strikes on case walls, and probe swaps between cartridges. Setting changes are one-button, accuracy is at the micrometer level, and on Mark 7 Autodrive presses the sensor stops the press automatically when a charge is outside your window. Pro models add data: every round logged with timestamps and exportable CSV, so you can prove — not assume — that a session ran clean. One customer running 9mm at 1,000 rounds per hour with ±.02"/.015" windows reported catching real undercharges of .05 grain or less with zero false high alarms (his full writeup is here).
The honest trade-off is price: $499–$699 versus $45–$200 for the mechanical options. If you load a few hundred rounds a month on a hand-cranked press and genuinely watch your cases, a Powder Cop or Lock-Out Die is decent insurance. The laser makes its case as volume rises: automation, four-digit hourly rates, tight competition tolerances, or commercial loading where you need a data trail. At those volumes the question flips from "why spend more?" to "what does one kaboom, one match DQ, or one afternoon of pulling bullets cost?"
Bottom line
Attentive manual loader on a budget: Powder Cop or Lock-Out Die. Dillon hand-cranker who wants an alert: Dillon Powder Check. Mark 7 owner wanting the cheapest integrated stop: Mark 7's PowderCheck is fair value, with the probe caveats above. High-volume, automated, competitive, or commercial: no-contact laser measurement with automatic press stop and logging is the only option in the group actually designed for how you load. Questions about your specific press? Ask us directly — we run these machines daily.
Keep reading
RCM Laser Powder Check vs. Mark 7 PowderCheck Sensor: An Honest Comparison · Squib Loads: What Causes Them and How to Prevent Them on a Progressive Press · Mark 7 PowderCheck False Alarms: Causes, Fixes, and When to Upgrade · Double Charges in 9mm: Why They Happen on Progressives and How to Catch Them