15 Minute Practical Trigger Job for the
Medcop was shooting Urodoji’s CAR-15 and had commented to
him on the excellent, smooth
trigger. I was asked to send Medcop a description
of how this was done. Urodoji got Medcop in touch with me, and I did some
sketches, and described to Medcop how to do it.
I thought this was common knowledge, but I was
asked on AR15.com’s Chat to write this up for
posting. So here goes…
Disclaimer: If you can’t follow these directions
successfully, you should not be playing with
guns, especially AR-15’s.
- Two Encyclopedias (you may sub two wood
blocks, these are used to prop up the lower receiver)
- Small punch (for trigger/hammer pins)
- Large soft punch (3/8” Delrin® rod
or 3/8” wood dowel)
- Fine compound (#7 rubbing compound or Kit
Scratch Out plastic polish)
- Wire Cutters
- Jeweler’s Pliers (small pliers with no teeth in
UNLOAD RIFLE AND SEPARATE UPPER
RECEIVER FROM LOWER RECEIVER
I had to say this, too. If you didn’t know this,
you should not be handling firearms.
- Remove the Safety (AR-15’s
have safeties, M16’s have selectors) to allow easy removal of the Trigger
later. Turn the Safety 45 degrees, halfway between SAFE and FIRE. Lay the
Lower Receiver on its left side on the two encyclopedias (with the Web,
they aren’t good for anything else) or wood blocks, covered with soft rags
such that the Lower Receiver is blocked up, and the Safety can be tapped
out. Tap out the Safety with the
large soft Delrin® punch or wood dowel. With the Safety halfway between Safe
and Fire it will pop out without having to remove the grip and detent.
Don’t worry about losing the Safety Detent, as it is captured by a groove
in its hole.
- Polish the sear surfaces. With
the Hammer in the up, or fired position, place a dab of
polishing compound on the Hammer sear surface. To prevent the hammer from
striking the receiver and possibly breaking the bolt stop, place a strip of
leather, rubber or plastic in front of the hammer. Cock the Hammer and
pull the Trigger. Repeat this 10 times. Put another dab of compound on the
Hammer’s sear surface, and cock and fire 10 more times.
- Now remove the Hammer first,
then the Trigger and Disconnector, by tapping out their pins.
- Clean off every trace of
compound from the Hammer and Trigger. Do it again to make sure. Clean any compound from inside the
the right leg of the Hammer Spring to a length of ¼”.
- Bend both legs of the Trigger
Spring UP approximately 25 degrees as per the diagram. Use Jeweler’s
pliers for this. You do not want to leave marks in the spring. Smooth
jawed pliers only!
- Reassemble the Trigger
assembly with the Trigger Pin’s outer retaining groove to the LEFT side of
- Install the Safety. A little
trick… Hold the detent down with the end of a ¼” punch while
tapping in the Safety from the other side.
- Install the Hammer. When
installing the Hammer Pin it does not matter which side the outer groove
is on. Notice that the left leg of the Hammer Spring engages the outer
groove of the Trigger Pin, which you installed to be on the left side,
retaining it in the Receiver. (You may also want to use “Anti-Walk Pins”.
If you use these, install these pins so that the E-clips are away from
your body to prevent the E-clips from snagging on your clothing and
possibly snapping off. If you are right-handed, the E-clips should be on
the right. And if you are left-handed, the E-clips should be on the left.)
- Lubricate all the moving lower
part; making sure you put a drop of oil on the Hammer sear surface.
Caution: DO NOT modify the Trigger Spring
without also modifying the Hammer Spring as described.
I have used this trigger job method for about 10
years now, and have NEVER had it fail to pop
the cap. Hammer Spring force is only reduced by
about 25%, and there is still plenty of power to insure good ignition. There is
still full sear engagement, so the trigger is not unsafe in any way.
This trigger job DOES result in a smoother,
lighter trigger pull.
If you are unhappy with your results, at the
most, you have only ruined two springs, three dollars worth of parts. This
slight polishing with the compound will not harm your Hammer and Trigger in any
A Free Man