New guy question on trigger pull

majbjd · 01-24-2013, 06:46 PM

I have a DWM 1913 9mm I got back in 1999. I started shooting it recently and am having an odd trigger pull. The trigger pull measures 64 oz. on a gauge and when dry fired with a snap cap it feels like a 4 lb pull, very similar to my 1911 .45 match gun. However, when fired with live ammo the pull is very light, feels less than the 2.5 lb pull on my S&W Mod 41 .22 match gun. It is what I would call a "hair trigger".
Is there some quirk in the Luger trigger system that would cause this or do I have a problem that needs to be fixed. I know 1911 triggers that get too light can cause the gun to double fire.

majbjd · 01-30-2013, 01:39 PM

Has nobody had an experience like this ? No opinions?

mrerick · 01-30-2013, 02:02 PM

Hi and welcome to the forum.

Trigger fit on a Luger is a rather precision task. I'd take a look at the sear surfaces to look for damage or wear. Also ensure that the correct recoil spring is installed.

Marc

majbjd · 02-04-2013, 11:51 PM

Finally got a chance to pull the gun apart. The trigger bar engagement surface shows a mating surface about .060 deep and very slightly off square or worn toward the edge. The sear face shows the same depth of engagement. The face is square but there are two deep scratches running from the center to the edge. Could these be the cause of the light trigger?

FNorm · 02-05-2013, 11:16 AM

Look also at your trigger spring. I found one with a replacement spring that was definitely not Luger.

FN

mrerick · 02-05-2013, 06:38 PM

What percentage of the sear and trigger bar surfaces are actually in contact?

Trigger let off pressure would involve the friction developed by having these surfaces in contact. If one surface just has two thin ridges instead of the entire surface it could be involved.

Marc

majbjd · 02-05-2013, 11:10 PM

The mating surfaces are about half of the total area of each surface. The scratches on the sear run at a 45 degree angle to the edge.

majbjd · 02-07-2013, 07:36 PM

OK, you can officially list me as an idiot. Took the gun to the range today to check out a couple of mecgar mags. They
work great, even fed my handloads that the factory mag would not feed.
While there I tested the trigger pull after the gun cycled with live ammo. I put a dummy round in the mag with a live round on top. Fired the live round, dummy chambered OK and tested the trigger pull. It was 61 oz. on three tests. Cycled by hand the pull tests at 64 oz..
After a bit of thinking I realized why the pull feels so light. The trigger on my 1911 is 68 oz. but the trigger is only 6.08mm wide. The Luger trigger is 10.3mm wide. The 1911 is flat, the Luger is curved and fits my finger tip like it make for it. More surface area equals less pressure per square inch, which equals less felt pressure.
Thanks for all the help. It did make me tear into the gun more than I have before so I did learn something.

01-24-2013, 06:46 PM	#1
majbjd User Join Date: Jan 2013 Location: Abilene Texas Posts: 6 Thanks: 0 Thanked 1 Time in 1 Post	New guy question on trigger pull I have a DWM 1913 9mm I got back in 1999. I started shooting it recently and am having an odd trigger pull. The trigger pull measures 64 oz. on a gauge and when dry fired with a snap cap it feels like a 4 lb pull, very similar to my 1911 .45 match gun. However, when fired with live ammo the pull is very light, feels less than the 2.5 lb pull on my S&W Mod 41 .22 match gun. It is what I would call a "hair trigger". Is there some quirk in the Luger trigger system that would cause this or do I have a problem that needs to be fixed. I know 1911 triggers that get too light can cause the gun to double fire.

01-30-2013, 02:02 PM	#3
mrerick Super Moderator - Patron LugerForum Life Patron Join Date: Dec 2009 Location: Eastern North Carolina, USA Posts: 3,909 Thanks: 1,374 Thanked 3,110 Times in 1,510 Posts	Hi and welcome to the forum. Trigger fit on a Luger is a rather precision task. I'd take a look at the sear surfaces to look for damage or wear. Also ensure that the correct recoil spring is installed. Marc __________________ Igitur si vis pacem, para bellum - - Therefore if you want peace, prepare for war.

02-05-2013, 06:38 PM	#6
mrerick Super Moderator - Patron LugerForum Life Patron Join Date: Dec 2009 Location: Eastern North Carolina, USA Posts: 3,909 Thanks: 1,374 Thanked 3,110 Times in 1,510 Posts	What percentage of the sear and trigger bar surfaces are actually in contact? Trigger let off pressure would involve the friction developed by having these surfaces in contact. If one surface just has two thin ridges instead of the entire surface it could be involved. Marc __________________ Igitur si vis pacem, para bellum - - Therefore if you want peace, prepare for war.

01-30-2013, 01:39 PM	#2
majbjd User Join Date: Jan 2013 Location: Abilene Texas Posts: 6 Thanks: 0 Thanked 1 Time in 1 Post	Has nobody had an experience like this ? No opinions?

02-04-2013, 11:51 PM	#4
majbjd User Join Date: Jan 2013 Location: Abilene Texas Posts: 6 Thanks: 0 Thanked 1 Time in 1 Post	Finally got a chance to pull the gun apart. The trigger bar engagement surface shows a mating surface about .060 deep and very slightly off square or worn toward the edge. The sear face shows the same depth of engagement. The face is square but there are two deep scratches running from the center to the edge. Could these be the cause of the light trigger?

02-05-2013, 11:16 AM	#5
FNorm Patron LugerForum Patron Join Date: Mar 2009 Location: Colorado Posts: 978 Thanks: 68 Thanked 127 Times in 108 Posts	Look also at your trigger spring. I found one with a replacement spring that was definitely not Luger. FN

02-05-2013, 11:10 PM	#7
majbjd User Join Date: Jan 2013 Location: Abilene Texas Posts: 6 Thanks: 0 Thanked 1 Time in 1 Post	The mating surfaces are about half of the total area of each surface. The scratches on the sear run at a 45 degree angle to the edge.

02-07-2013, 07:36 PM	#8
majbjd User Join Date: Jan 2013 Location: Abilene Texas Posts: 6 Thanks: 0 Thanked 1 Time in 1 Post	OK, you can officially list me as an idiot. Took the gun to the range today to check out a couple of mecgar mags. They work great, even fed my handloads that the factory mag would not feed. While there I tested the trigger pull after the gun cycled with live ammo. I put a dummy round in the mag with a live round on top. Fired the live round, dummy chambered OK and tested the trigger pull. It was 61 oz. on three tests. Cycled by hand the pull tests at 64 oz.. After a bit of thinking I realized why the pull feels so light. The trigger on my 1911 is 68 oz. but the trigger is only 6.08mm wide. The Luger trigger is 10.3mm wide. The 1911 is flat, the Luger is curved and fits my finger tip like it make for it. More surface area equals less pressure per square inch, which equals less felt pressure. Thanks for all the help. It did make me tear into the gun more than I have before so I did learn something.