Gun shop wisdom says a good trigger makes all the difference.
It should be obvious that replacing the trigger doesn’t have any physical impact on a rifle’s accuracy. It’s not like it synchronizes barrel harmonics to the tune of “You’re So Vain” or anything. A trigger doesn’t touch the barrel or impact flight path, yet everyone swears it makes a rifle more accurate.
That’s kind of true. But it doesn’t make the rifle more accurate, it makes it easier for you, the shooter, to get the best accuracy that the rifle is capable of. This is an important distinction.
The reason is that pesky physics thing. When a rifle takes several pounds of pressure to break the shot, and the rifle itself only weighs several pounds, it’s gonna want to move, at least a little bit. A good trigger, with a smooth action and reasonably low pull weight, is going to make it easier for you to break the shot without moving the sight alignment of the rifle. When you’re trying to extract every last fraction of an inch of accuracy, a little bit of unwanted movement means a lot on the target.
According to John Vehr, President of Timney Triggers, “There is only one reason to upgrade a trigger in a firearm – to make you more accurate with the firearm. A great trigger will allow you to become more accurate by eliminating physical factors like drag, creep and heaviness – Less movement equals better accuracy. A great trigger will allow the shooter to make the act of pulling the trigger more of a mental decision that a physical decision. A great trigger is an extension of the mind and should break exactly when the shooter calls for the shot.”
Gaining more practical accuracy by using a custom trigger sounds great in theory, but I wanted to put it to the test in a quantifiable way.
I decided to take two rifles of proven quality and accuracy, but with less than optimal triggers, and test their accuracy before and after a trigger upgrade. The folks at Timney Triggers sent me an AR-15 Competition trigger for the test. This trigger, the 3 pound 667 model, is a self-contained unit with drop-in installation.
My thought for the test was simple. Shoot groups of 5 shots each with each rifle with its standard factory trigger. While at the range, swap the trigger for the Timney AR-15 Competition trigger, and reshoot the groups. Same ammunition, same rest, same day, same atmospheric conditions and same shooter. When all was done, I figured on applying some common core math to compare the average group sizes before and after. Then I realized that this article was due in 2014, so I skipped the common core stuff and added, subtracted and averaged the old fashioned way.