Luger Trigger Tuning Part III

Hugh · 03-18-2002, 02:44 AM

This one will make Hakan have puppies! Sorry Hakan!

The top picture posted in step #2 should have been posted with this step.

This step should only be attempted by those familiar with using a Micrometer.

The direct sear engagement between the trigger bar and the firing pin lug is roughly .015 to .020 inch greater than necessary for safe operation. In this step you are going to remove this amount of sear engagement.

1. Use a micrometer to measure across the base of the firing pin including the lug, and record the total width.

2. After securing the firing pin in a vise, begin filing the outside surface of its lug in very small amounts at a time. Measure after every 3 or 4 strokes, being careful to stop after youÃ¢??ve removed .015 inch or so of metal.

3. Now place the firing pin back into the breechblock , but do not replace the firing pin spring or guide. Insert the breech block and toggle assembly into the receiver and secure with the receiver axle. With the barrel pointing downward, snap the breechblock forward into battery. The trigger bar (sear) will catch the firing pin, holding it to the rear.

4. Watching the rear half of the trigger bar, slowly push in the trigger barÃ¢??s forward end until the firing pin is released and falls forward. Repeat this several times, noting how much trigger bar travel is required before the firing pin falls. The trigger bar should move at least 1/32 of an inch before the firing pin drops, and 3/64 of an inch would be absolutely safe. If necessary, continue to file down the firing pin lug until the firing pin drops at 3/64 inch of trigger bar travel.

Measure the firing pin once again with the micrometer, noting how much metal has been removed.

Do not continue past this point, as to do so is inviting full automatic fire if the trigger bar plunger should cam in front of the trigger lever as the receiver returns to battery from recoil.

5. Polish all work done thus far with 600 wet or dry sand paper followed by crocus cloth to a glass smooth surface. Polish both bearing surfaces of the trigger lever and the underside of the trigger lip that engages the trigger lever glass smooth.

6. Completely reassemble the gun and check for functioning as follows:

1. With the magazine removed, allow the toggle and breechblock to snap forward several times, making sure that sear engagement is positive.

2. With the trigger held to the rear, manually push the receiver out of battery, and release it several times to assure that the trigger bar plunger is catching the trigger lever as it returns to battery. With the receiver fully in battery, an audible click should be heard as the trigger is released, indicating proper functioning of the trigger bar plunger.

After all of this work, you should have a Luger with a silky-smooth, two pound trigger pull with 100 % positive functioning of all trigger-sear components.

03-18-2002, 02:44 AM	#1
Hugh RIP Join Date: Jun 2002 Location: Southeast Texas Swamp Posts: 2,460 Thanks: 2 Thanked 166 Times in 65 Posts	Luger Trigger Tuning Part III This one will make Hakan have puppies! Sorry Hakan! The top picture posted in step #2 should have been posted with this step. This step should only be attempted by those familiar with using a Micrometer. The direct sear engagement between the trigger bar and the firing pin lug is roughly .015 to .020 inch greater than necessary for safe operation. In this step you are going to remove this amount of sear engagement. 1. Use a micrometer to measure across the base of the firing pin including the lug, and record the total width. 2. After securing the firing pin in a vise, begin filing the outside surface of its lug in very small amounts at a time. Measure after every 3 or 4 strokes, being careful to stop after youÃ¢??ve removed .015 inch or so of metal. 3. Now place the firing pin back into the breechblock , but do not replace the firing pin spring or guide. Insert the breech block and toggle assembly into the receiver and secure with the receiver axle. With the barrel pointing downward, snap the breechblock forward into battery. The trigger bar (sear) will catch the firing pin, holding it to the rear. 4. Watching the rear half of the trigger bar, slowly push in the trigger barÃ¢??s forward end until the firing pin is released and falls forward. Repeat this several times, noting how much trigger bar travel is required before the firing pin falls. The trigger bar should move at least 1/32 of an inch before the firing pin drops, and 3/64 of an inch would be absolutely safe. If necessary, continue to file down the firing pin lug until the firing pin drops at 3/64 inch of trigger bar travel. Measure the firing pin once again with the micrometer, noting how much metal has been removed. Do not continue past this point, as to do so is inviting full automatic fire if the trigger bar plunger should cam in front of the trigger lever as the receiver returns to battery from recoil. 5. Polish all work done thus far with 600 wet or dry sand paper followed by crocus cloth to a glass smooth surface. Polish both bearing surfaces of the trigger lever and the underside of the trigger lip that engages the trigger lever glass smooth. 6. Completely reassemble the gun and check for functioning as follows: 1. With the magazine removed, allow the toggle and breechblock to snap forward several times, making sure that sear engagement is positive. 2. With the trigger held to the rear, manually push the receiver out of battery, and release it several times to assure that the trigger bar plunger is catching the trigger lever as it returns to battery. With the receiver fully in battery, an audible click should be heard as the trigger is released, indicating proper functioning of the trigger bar plunger. After all of this work, you should have a Luger with a silky-smooth, two pound trigger pull with 100 % positive functioning of all trigger-sear components.