CMC Drop-in Trigger Pack


Steve Coulston gets intimate with CMC’s top notch, match grade drop-in trigger pack.

Pioneers are unique individuals. They aren’t unique because they accomplished some amazing feat, although that is very impressive and noteworthy in its own right. They are unique because they had the vision and the courage to take the first step. Then after the first step, they took another and another until they reached their goal. Though they may fail, they don’t let that failure define them, rather they learn and grow from that experience, get up and move forward, forging ahead into the unknown, paving the way for others to follow. When we think of pioneers we think of Columbus or Lewis and Clark or maybe the Apollo 11 mission when Neil Armstrong walked on the moon. Even though they discovered different places and made many different choices along the way they all made one universal decision. They decided to go.

While building an AR ain’t exactly walkin’ on the moon, the engineering and design development that goes into the sum of the parts is impressive. The trigger is one of the key components to breaking the shot clean and sending the bullet off on its journey. Back in 2003 a pioneer named Chip McCormick embarked on a journey to develop the first drop-in trigger pack. Through many trials and errors, Chip eventually realized his vision. Eventually the trigger was patented under patent number 7,162,824. With the help of his engineer, Jack Biegel, Chip worked for the next two years to produce 6,000 trigger packs. In 2005 Chip and Jack stopped producing triggers and Jack left to go back to work in the aerospace industry. In 2010 Jack starting up his own machine shop and resumed making triggers for Chip until 2011 when Chip sold the company to Jack. Jack currently owns and runs CMC Trigger Company with his daughter, Jennifer. Even though the drop-in trigger patent was sold to O.F. Mossberg & Sons a few years back, CMC still holds the patent on the flat trigger concept.

Based out of Ft. Worth, Texas, CMC Triggers continues to push the envelope in trigger design. They pride themselves in manufacturing top notch, match grade drop-in trigger packs. Their triggers are completely self-contained and are easy to install. Before the drop-in trigger, getting a precision, match grade trigger took a lot of money and usually required a gun smith to install in and tune it correctly. Now, you can have a trigger that has an exceptional trigger pull and break and can be installed very easily in all mil-spec receivers. CMC also offer models that will fit Colt brand rifles with the larger .171 inch diameter pins as well as AR10 receivers. Rest assured, when you purchase a CMC trigger you are getting a high quality trigger.

The trigger pack is a one-piece unit and comes with supplied trigger pins that have screw heads on the end so they won’t “walk” or back out of the lower receiver. The internals of the trigger pack are void of any screws or adhesives so there isn’t anything to adjust or tweak or work loose. Also, there isn’t any user adjust-ability in the design. It is set from the factory and doesn’t lend itself for the curious tinkerer in all of us to mess it up. As they state on their website, the CMC trigger pack also features “full-strength rocket wire springs for fast lock times and reliable discharge with factory or military ammo.” That being said, they do not recommend using this trigger with rifles chambered for 5.45×39 ammunition. All of the engagement surfaces are made to tolerances of +/- .001”. The housing is made of 410 stainless steel and the trigger, disconnector, hammer and pins are made with the hardest wearing materials available. Those materials are proprietary and were not disclosed during the interview. CMC offers a wide variety of triggers that consist of a flat or curved face, different colors and different trigger pull weights. CMC also has a strict quality control process. Jack stated, “100% inspection occurs on all critical engagement dimensions. No exceptions.” When asked to elaborate, he informed us it was a proprietary process, which he was not willing to disclose. The triggers have been tested and documented to over 25,000 machine generated cycles. Those same tested parts were then put through a 500 round, live fire test. After the test was complete, no fractures, cracks or failures were found. CMC states, “every characteristic of the trigger groups undergo hundreds of thousands of rounds of cycle testing to ensure reliability before [they] ever release a design update.”

The trigger I ended up buying, was the flat-faced trigger with a 3.5 lb trigger pull. This is CMC part number 91503. This was the first flat-faced trigger I had ever used in an AR. The trigger came with the trigger group, assembly pins, retention pin set and two wrenches. Installation was quick and easy and took all of 3 minutes. The AR that I dropped it into already had a battery assist lever installed. The flat-faced trigger put my finger more forward on the trigger, which resulted in a very small opening between the trigger and the battery assist lever. I ended up removing the lever in favor of more positive trigger control. On the range, the trigger performed flawlessly. I found that for longer, more precise shots, I could place my finger lower on the trigger for precise accurate control. For faster, follow up shots, I would place my finger higher on the trigger for a more rapid operation of the trigger. There was zero take up on the trigger and the single stage broke at a very crisp 3.5 lbs as advertised. The reset was extremely short and pronounced resulting in ultra-fast follow up shots. The trigger didn’t have to go through a break in period and was consistent from start to finish. For those that know me, I like to shoot fast. I am not talking Jerry Miculek fast, but I can shoot fast enough for my needs. While everyone’s ability will vary, I found that I could shoot the CMC trigger at a fairly rapid rate. I was using the very effective Elite Iron OP-COMP compensator so doing mag dumps and staying on target was an easy day.

Over all I was very impressed and am very happy with my purchase. The quality and function of the trigger is outstanding. The cost was minimal when compared to other precision triggers on the market. I bought mine at Rainier Arms for $167.99. For that price, it is hard to beat. On top of that CMC offers their customers guaranteed satisfaction and will refund the price of the trigger if returned within 30 days of purchase. Jack also made a point to state, “If there is anything wrong with the […] trigger, we will fix it or replace it with a new one. We honor every trigger ever built by CMC.” For more information check out


  1. Great review of CMC triggers by Steve Coulston. I tried one of these, after installing other, and much more expensive custom unit built triggers. Not only are the nearly $100 less expensive, but just as effective, great glass like break, near zero take up, and fast reset, makes this not only a great trigger for competition or as a tactical weapon, as my other “big name”, overly expensive units. I’m ready to order another, for a new lightweight rifle, and expect the same quality at a bargain price point. These are great units, and worth a try by anyone wanting a great trigger at a realistic price.

Comments are closed.