This text assumes that the trigger group is mechanically sound, and that hammer hook and sear angles are correct and in agreement. We assume no liability for bad or incorrect parts...drop-in replacement of parts...or incorrectly following the outlined procedures. Whenever performing work on the fire control group in a Model 1911 Colt-Browning pistol, there is always the risk of burst-fire or unexpected fully automatic fire., and the reader must assume full responsibility. This is not to state that these problems are highly likely...only that they are a possibility.
One sheet of 600-grit wet or dry paper. (Auto body sand paper)
Detail strip the pistol and lay out the following parts: Hammer, sear, disconnect, trigger, sear spring, mainspring housing, if mainspring replacement is indicated .(10,000 rounds or more through the gun)
Check all above fire control parts for sharp corners, burrs, tool marks. Do a preliminary check of the disconnect to see that it will slip into place with the paddle against the trigger stirrup and fall out of its channel by gravity.
Use a flat needle file to lightly dress any sharp corners on the sides and back of the head, but don't touch the front. (Sharp edges there should be lightly polished on the denim cloth with J&B.) Lay the flat part of the paddle flat on the India stone and work it back and forth to dress tool marks. If the paddle has a parting line, don't try to completely remove it...just smooth it a little. Use a small piece of 600-grit paper on the stone or a piece of glass to lap the disconnect's face in a small figure "8" pattern. Use a drop of honing oil on the paper. Move to the denim cloth impregnated with the J&B compound and buff briskly. Feel for sharp corners on the edge of the paddle, and use the stone to break the edges away from the paddle face at a 30-degree angle. Don't get aggressive on this...One light swipe on the stone will ususally do. Polish the front of the disconnector head now.
Polish the rear of the paddle on the 48 degree angle. Don't get aggressive on this. All you want is to smooth it and reduce deep tool marks. Straight up and down motions with light pressure will do it. Buff it on the denim.
Lightly polish the top of the paddle with the ceramic stone...the areas on either side of the stem, and be sure to get into the corners that are formed by the paddle and the stem. Break the corners lightly on an angle. Don't remove material...just break any burrs or edges.
Swipe the corners on the sides of the tip on the stone. Break the corners away from the tip to keep from kicking up a burr on top. Do NOT file or stone the very tip. Buff the tip and the front and rear angles on the denim cloth but don't do anything that would shorten it or change the angles. Lay the disconnect aside.
Feel along the length of the bow and stirrup for sharp edges or burrs and dress them off with the stone at a 45 degree angle. Sharp corners on the stirrup should be dressed with the file at a 45 degree angle to the stirrup itself...top and bottom. Follow up with the stone to smooth file marks.
Check to see that the trigger will fall in and out of the track under gravity. If not, color the bow with the felt tip marker and slide it in and out to find the contact points and polish on the dry stone lightly. If the trigger bow is "bowed...in or out...it will need to be straightened on a fixture or replaced. Use the glass plate and the sandpaper to polish the sides of the bow with brisk, lengthwise strokes. Redo the gravity test often. Try to polish both sides evenly, by using 10 strokes at a time. Flip the trigger over and use 10 on the other side. Recheck for sharp corners and dress them on the paper lengthwise. Buff the bow briskly on the denim.
Pre-dress the rear of the bow...the stirrup...on the paper and glass. Start with side to side motions, and finish up with a figure "8" pattern and honing oil. If the stirrup is uneven, don't try to make it perfectly flat by dressing. If it's too far out of tolerance, it should be straightened on a fixture or replaced. Recheck for burrs and dress acordingly. Lay the trigger aside.
Do NOT file, polish, buff, or alter the primary angle.
Check for sharp corners or burrs on the sides of the sear. Dress lightly with the stone, and polish the sides on the paper and glass in a circular pattern using light pressure. Recheck for burrs and dress them on the paper.
Use a swiping motion to lightly dress the bottoms of the sear legs, but just enough to clean them up a little. Use light pressure, and follow the shape. Use the stone to lightly break the corner on the trigger side of the bottom of the legs, moving away from the bottom face. Buff this area on the denim.
Lay the sear on the stone with the convex curve facing up, so that the backside of the primary angle is on the stone. Place the .020 feeler gauge under the legs, and push the sear along the stone from bottom to top to create a light breakaway angle on the back of the sear. Be careful to keep the legs on the feeler gauge. When the dressed line on the back of the sear is roughly 1/4th the width of the primary angle...stop.
Sear spring prep:
Use the stone to establish about a 30-degree angle on the tops of the left and middle sear spring legs on the side facing the front of the gun. Colt sear springs already have this angle, and polishing is all that will be required. Use the sandpaper on glass for this. Push the spring from bottom toward top to prevent kicking up a burr on the contact surfaces. Establish and polish an angle on the BACKside of the far right leg...the one that drives the grip safety. Don't bend or tweak the leaves to reduce tension on sear and disconnect. They are fine as they are.
Clamp the hammer in the vise and use the squaring file to lightly square the hooks with the safe edge against the hammer so that you cut only the hooks. be careful to keep it square, and bear evenly on both hooks. 2 or 3 light strokes will do.
Lay the .025 gauge under the hooks and stone both hooks down flush with the gauge, being careful to keep the stone flat as you finish. Do NOT be tempted to use the .020 gauge. Use pressure on the gauge to keep it flat in the floor...(at the bottom of the hooks)
Dab a little lapping compound into the hook area, and wipe off the excess Use the lathe blank to square and clean up the hooks with light pressure. Be careful to bear evenly on both hooks, using medium-light pressure. Apply pressure at a 45 degree angle to force the square corner of the tool into the corners formed by the hooks. 8 or 10 back and forth strokes will do. Clean the compound off with alcohol. Color the sear primary angle with the marker and assemble the frame, leaving the thumb and grip safety out. Assemble the frame, slide, barrel, bushing and slidestop. Boost the hammer lightly with thumb pressure and dry-fire the gun 4-5 times. Use the flashlight and look closely at the sear to see if both hammer hooks are bearing evenly on it. If not, use the ceramic stone under the hook that has been cleaned of color. The difference will likely be minimal, so go slow. Perform the check again. When you just start to see ink removed from the side that wasn't touching...stop. Use the white stone to lightly polish both hooks evenly...8-10 strokes.
Polish the sides, front, and back of the hammer strut with the sandpaper. Buff the tip on the denim. Install the new mainspring...no lighter than 21 pound rating, with 23 pounds recommended. Use the flat edge of the India stone to lightly dress the disconnector/cocking rail in the center of the slide. Don't try to remove deep tool marks...Just knock off the high spots. If the stone won't fit between the outer rails, find a flat piece of steel and use the sandpaper for this.
Series 80 Colts note:
Polish the sides of the trigger bar lever and plunger lever lightly on the paper and glass. Buff briskly on the denim and glass. Note any sharp edges and dress them free-hand with the paper...lightly.
Lube and assemble the frame and cock the hammer. Dribble a little gun oil into the area between the front of the hammer and the frame. Assemble the pistol and dry-fire the gun several times while boosting the hammer lightly with your thumb. Your trigger should be much inproved.
Test fire by loading several magazines with 2 rounds each. If no hammer follow or burst fire is evident, step up to 3 rounds for a few magazines. If all these steps are followed carefully, there shouldn't be a problem, but any time work is done on the trigger group/fire control parts, this test should be done until the work proves itself to be safe.