Shooters are a lot like farmers; in order to be happy they need something to grouse about. I’ve never met a farmer who had a good year. It’s always too wet or the drought killed their crops; hog prices went so soft they ate up every penny of profit; and so forth. Shooters go off about bedding, twist rate for the bullet they chose, loose scope screws, and on and on. I’m no different. My favorite complaint is lousy triggers. I know I could have shot a better group if that dang gun had a decent trigger!
In the AR-15 platform a lot is asked of the fire-control mechanism. First and foremost, it must be reliable. By that I mean it must release the hammer and fire the gun each time the trigger is pulled, and it is imperative the trigger hold that hammer when it is released. And it must do both of those things without fail...every time...because peoples’ lives depend on that reliability. Those two parameters are pretty easily accomplished, but when you add the requirement that the trigger be light enough to minimize disturbing the aim of the rifle and further that it release with minimal creep and overtravel, well, that’s why we have gunsmiths. Of course, the AR-15 has moved past the purely tactical rifle, and now is quite popular among varmint and target shooters. If you ever want to see a real pining fest, get a group of these guys around a fire and talk triggers.
Chip McCormick went on a prairie dog shoot using AR-15s in 2000, and he came away wondering what he could do to make a really good and reliable trigger for this rifle. The AR-15 fire-control mechanism is composed of eight major parts: trigger, hammer, disconnector, three music-wire springs and a pair of steel pins to retain them. Assembling it in the cavity of the lower receiver can have you wishing for a third hand and using language that wouldn’t do in church. Coming up with a trigger that meets the critical demands of the match and varmint shooters, as well as being reliable enough for a tactical shooter is tough enough. Making it as an aftermarket trigger that fits in virtually any AR by any manufacturer is a near nightmare. Even though this is the standard U.S. service rifle and its dimensions and tolerances have been set, there are nonetheless many dimensional variations from manufacturer to manufacturer. They may not be much, but in the macro world of triggers in a semi-automatic rifle those departures from uniformity are a headache.
Using his talents as a designer and a machinist, McCormick developed a modular fire-control assembly for the AR-15 that addresses each of the criteria I’ve set forth. It’s so easy to install, even I could do it in less than two minutes—and I am by no means an expert AR mechanic. Instead of necessitating the gyrations typical when trying to hold the components together under spring tension while you install the two pins that keep everything together, McCormick’s Super Match AR-15 Trigger Group drops easily into place. Tap the slightly oversize pins home, replace the safety switch, and you’re good to go.
I looked over our inventory and borrowed a Smith & Wesson M&P15 carbine to see how well this all worked. Before disassembling the lower receiver I checked the trigger pull. It averaged 7 pounds, 5 ounces on my Lyman Digital Trigger Pull Gauge. Bing, bang, boom, and I had the carbine back together with the McCormick trigger. The new trigger pull? Try 4 pounds, 10 ounces. Now that may not be one of those sub-pound whisper triggers seen on a benchrest gun, but it’s far better than the OEM trigger—nearly 40 percent better. The trigger sent to me for review is set to NRA High Power National Match standards with a minimum pull weight of 4 1/2 pounds. A 3 1/2-pounder is available for those wanting something lighter and not competing at Camp Perry—say for example a varmint shooter. The trigger group is not adjustable because, according to McCormick’s website, the only reason for an adjustable trigger is to facilitate reliability when assembling a conventional, non-modular one.
About three years ago I was enjoying myself immensely pattering about the trigger in my DPMS AR-15. Eric Poole, who you have seen in these pages, asked me to let him look at the rifle. A couple of weeks later he handed it back to me and asked me what I thought. He had installed a 3 1/2-pound version of McCormick’s Super Match AR-15 Trigger Group. The expletive I used after tripping it the first time cannot and should not appear here, but trust me, it was an expletive of endearment. That rifle is going with me on a prairie dog shoot later this spring. I wish I knew then how easy it was to upgrade its trigger. I may like to complain, but I like shooting a lot more.
—Dave Campbell