Dillon Rifle Company Operator Inset Trigger for AR-15s: Review

Yes, that’s a trigger safety on the OPAR Operator Trigger from Dillon Rifle Company. Its proper name is an inset trigger, and the concept is familiar to rifle shooters and striker-fired handgun owners. The inset trigger must be depressed before the primary trigger can release the firing mechanism. The reason you are seeing it on an AR trigger is due to Dillon Rifle Company’s Brodie Renner’s close call when serving as a Naval Special Warfare Sniper in Iraq.

While sitting in a helicopter in anticipation of an insertion, Renner heard a shot go off and felt the heat of a round between his legs. He assumed they were taking enemy fire, but it came from his fellow sniper, who explained that as he shuffled his seating position, it caused an accidental discharge. Fortunately, no one was hurt, nor did it impair the helicopter. Later, when he began working for the newly established Dillon Rifle Company, they brainstormed on what product they could bring to market that was different than anything else. Renner proposed making a safer trigger, and the OPAR Operator Trigger was born.

The OPAR Operator Trigger is a drop-in trigger made from various alloy and tool steels. The housing is made from 7075 aluminum. Mechanically, this trigger is a simple but unique design. It’s a pre-staged trigger whose sear engagement is trapped into position by a safety block (my terminology). When the inset trigger is pressed, it moves the safety block forward, leaving an open channel for the primary trigger to disengage from the hammer. After firing a round and releasing the inset trigger, the primary trigger and safety block reset to the pre-staged position. The trigger breaks at 5 pounds.

Judging by the safety mechanism and 5-pound trigger press weight, it’s clear that preventing accidental discharges is the main reason for the design, but there are several aspects to the way the trigger is engineered that make it a highly effective design. The inset trigger is housed within the primary, rather than jutting out prominently. This exposes less surface area, which reduces the likelihood that it can be depressed from an angular force. Typically, a standard trigger has a 180-degree area of engagement. The OPAR Operator Trigger has reduced that to 100 degrees. In the testing I perform below, you will get an idea of how significant this is. Dillon Rifle Company will be releasing the Straight Trigger, which narrows the area of engagement to 30 degrees.

The target market for this trigger is not for those who are looking for the lightest trigger on the market. This is a trigger for those who seek an additional layer of safety with little compromise. Those in law enforcement, the military, and hunters who hold an AR close to their body and carry a lot of gear are prime candidates for this trigger. They are more likely to jostle the safety selector into the Fire position should a piece of gear, buckle, or strap find itself near the trigger housing. A bad confluence of events can lead to a very unfortunate mishap like what happened to Renner.

Range Time

You can’t get to know a trigger without firing it with live ammo, so I took it to the range and tested it while I reviewed several other AR components. The reset and weight are more than what I’m used to, but once I learned the trigger’s rhythm and pressure, it became a sweet trigger to shoot. The 5 pounds does seem like a lot compared to the 3-pound triggers I prefer for an AR, but the trigger breaks so crisply and consistently that it is a joy to shoot. Each trigger press and reset felt identical and reliable as I drove shot after shot at the targets.

While shooting, I discovered there is an optimal finger placement for the gun to go bang. The pad of your trigger finger digit should be on the hump or a little higher. Don’t ride the bottom of the trigger, or it may not depress the inset trigger fully. Too high, and it will take more pressure to depress the primary trigger like with any lever. Also, if you stick too much of the digit of your trigger finger onto the shoe, the crease at the bend may lie above the inset trigger and not depress the inset trigger fully. It will feel like you’re pressing the trigger, but most of your finger is pressing on the primary trigger. When I was consistent with my finger placement, the trigger responded consistently. In the end, the design encourages proper finger placement.

Paracord and Flashlight Test

Since this trigger has a narrow area of engagement, for safety reasons, I conducted a couple of tests at home to see if I could accidently set the trigger off with paracord and a flashlight. I removed the upper receiver and placed the lower receiver in Wheeler Engineering’s AR-15 Armorer’s Vise. This vice holds the receiver by the magwell and uses a rubber bumper to absorb the blows of the slamming hammer.

With the paracord, I looped it around the bottom of the trigger below the hump. The cord was contacting the inset trigger and primary trigger, and I pulled it directly rearward. The trigger didn’t release even when yanking it hard. I did this at the middle of the trigger, pulled the paracord tightly rearward again, and the hammer fell like it should. I then placed it in the upper-most part where it still contacted the inset trigger and pulled the cord at an upward angle like I was strangling the trigger. The hammer didn’t budge.

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Next, I placed the cord at various angles, touching the inset trigger partially but making strong contact with the primary trigger — still nothing, even when tugging heavily. The only time it fell was when I inadvertently made full contact with the inset trigger’s sweet spot. With the flashlight test, I aggressively shoved a SureFire G2X Pro flashlight lengthwise into the triggerguard and rocked it back and forth. The flashlight’s 1-inch diameter body filled the triggerguard with a little space for the trigger. The flashlight made hard contact with the sides of the primary trigger but didn’t release it. The only way I could get the hammer to fall was by pulling the flashlight rearward and perpendicular to the shoe.

Lastly, I implemented the same tests with a run-of-the-mill 7-pound AR trigger and an aftermarket 3-pound trigger. The hammer fell in every position with the force it takes to press the trigger. It is clear to me that Dillon Rifle Company achieved their objective with the OPAR Operator Trigger, especially after the flashlight test. The price for the OPAR is $265, which isn’t cheap, but if you are looking for an added level of safety, this is your trigger.