How to Install an AR-15 Trigger
Woody's answers are based on published federal and state law. Not legal advice. Consult a licensed attorney for your specific situation.
Remove the safety selector and trigger guard, then install the new trigger and hammer with their springs and pins. Ensure proper engagement between trigger, hammer, and disconnector before reassembling.
How This Affects Your Build
Installing an aftermarket trigger is one of the most impactful upgrades you can make to an AR-15, dramatically improving both accuracy potential and shooting experience. The process requires attention to detail and proper spring tension, but it's well within the capability of most builders with basic tools.
The Detail
Start by ensuring your rifle is completely unloaded and the bolt carrier group is removed. Push out the safety selector detent and remove the selector itself, then drive out the trigger guard roll pin and swing the guard down. This gives you access to the trigger pocket where you'll be working.
Next, punch out the hammer pin from left to right, catching the hammer and hammer spring as they come free. The disconnector spring is small and under tension, so work slowly here. Remove the trigger pin the same way, and the trigger assembly will drop out along with its spring.
Install your new trigger by reversing this process, but pay close attention to spring orientation and engagement surfaces. The hammer spring legs should sit properly in their channels, and the trigger spring should have the right tension against the trigger. Many aftermarket triggers come with specific installation instructions that differ slightly from mil-spec procedures.
Before you close everything up, function check the trigger thoroughly. The hammer should fall when you pull the trigger, reset properly when you cycle the action, and the safety should block the trigger when engaged. Any binding or failure to reset indicates improper installation that needs correction.
Build Impact
A quality trigger upgrade can transform your shooting experience, often reducing pull weight from the standard 6-8 pounds down to 3-4 pounds with a much cleaner break. However, this modification requires careful attention to safety function, and some competition triggers may not be suitable for duty or defensive use.