Glock 3rd - 4th Gen trigger issues explained

[Buck]

Having looked at a very large number of 3rd generation Glocks, 4th gereration Glocks, and the current 3rd generation Glocks with 4th generation trigger bars, I am certain that I have diagnosed the trigger issues that are being experienced by some.

First, other than the dimple on the trigger bar itself, there is no difference between the late 3rd and current 4th generation trigger bar. None. It is not stiffer, nor is it made of different materials. The angles and dimensions are exact. The parts are interchangeable and all of the current deliveries of third generation Glocks that I have seen have come with the 4th generation trigger bars installed.



The issue is that the 3rd generation Glocks with 4th generation trigger bars have a very heavy stiff trigger. Some have been measured at over 8 pounds.

Whilst other that the dimple, the trigger bars are exact, the trigger mechanism housings are very different and not interchangeable. Due to the shorter frame of the 4th generation pistols to accommodate the back straps, the angle that the 4th generation trigger mechanism housing holds the connector at is approximately 5 degrees less than that of the 3rd.

So the question becomes why is the dimple there and what does its interaction with the angle of the connector have to do with the trigger weight?

Some people believe that the dimple on the 4th generation trigger bar is dragging on the slide creating friction, and this is causing the issue. This is not correct. There is no noticeable difference in the first two thirds of the movement of the trigger bar and the disengagement of the firing pin safety between the generations, it is in the final third of the movement that it stiffens up.

Examining the second half of the movement of the trigger bars and comparing the 3rd and 4th Generation bars in motion, the reason for the dimple becomes apparent. In the final third of the movement of the 3rd generation trigger bar, in addition to moving to the rear, the bar itself moves away from the center line of the pistol and presses against the frame. This movement away from the center line of the pistol serves to smooth out the trigger pull. The dimple on the 4th generation trigger bar is in contact with the slide and it physically prevents this movement away from the centerline of the pistol in the final third of its movement stroke and keeps the trigger bar completely straight.

This straight trigger bar coupled with the smaller angle of the connector in the 4th generation guns increases the weight of the trigger by about one pound (+/-); However, it is in the new 3rd generation Glocks that are using the 3rd generation trigger mechanism housing with its increase in the angle of the connector, coupled with the dimpled 4th generation trigger bar that prevents it from moving away from the center line of the pistol to ease the pressure in the final third of its movement that show the most problems. It is this change of ratio that is causing them to have eight pound (+/-) triggers.

Just my .02

B

[Magic_Salad0892]

Does this mean that switching trigger bars between generations can be functional but is not advised?

[m4fun]

unless you like an ability to go to an 8lb pull - ouch!

[SERT103]

Great post. You can really see how the cruciform drops down and to the right on the 3rd gen Glocks when you install the orange armorers slide cover. On the 4th gens, it stays straight through the entire pull of the trigger. I have noticed too, that it appears more of the cruciform is engaging the firing pin as well. Usually the the 3rd gens only engage about 2/3.

[Buck]

Does this mean that switching trigger bars between generations can be functional but is not advised?

They should be switchable; however, I am unsure how a 3rd gen trigger bar will function in a 4th gen gun. We know that a 4th gen trigger bar in a 3rd gen gun with a normal connector gives an 8lb trigger...

B

[Robb Jensen]

Glock says if the 4th gen trigger pull is satisfactory to use a 3rd gen trigger bar....well since I took the Advanced Armorers class at Glock last summer.

[Drew78]

With all the info from the OP, would installing a 3.5 lb connector get a gen4 back into a trigger pull feel as the prior gen3's?

Anyone do this? If so I would welcome your feedback.

Drew

[SERT103]

With all the info from the OP, would installing a 3.5 lb connector get a gen4 back into a trigger pull feel as the prior gen3's?

Anyone do this? If so I would welcome your feedback.

Drew

I have installed an OEM "-" connector on my Gen4 G23 and its much better. It's just a hair heavier than my Gen 3 set up the same way.

[Kilo 1-1]

With all the info from the OP, would installing a 3.5 lb connector get a gen4 back into a trigger pull feel as the prior gen3's?

Anyone do this? If so I would welcome your feedback.

Drew

Not quite. I had a friend put an aftermarket 3.5 disconnect into his G19 gen4, and the pull was still....not great.

It was only after carefully polishing the trigger and using stock disconnect did it feel remotely kinda like a stock Gen 3 trigger again.

This is a sample size of one though.

[jh9]

They should be switchable; however, I am unsure how a 3rd gen trigger bar will function in a 4th gen gun. We know that a 4th gen trigger bar in a 3rd gen gun with a normal connector gives an 8lb trigger...

B

900 rounds and change through my gen4 17, at least half of those being with the replacement, old standard, non-dimpled trigger bar. The trigger seems to work fine so far. I was unaware of anyone having issues with this configuration.

The vanek polished factory "3.5lb" connector and correct, standard g17, non-g37-dimpled trigger bar measured 5lbs on a (Lyman?) trigger pull gauge. Wasn't digital (or my gauge) so I guess that could be approximate. Stock felt like more than 8lbs, but I didn't measure it.

(That doesn't say anything about my ejection issues with the 02 spring (which I had with the stock g37 trigger bar as well)...but there have been no trigger related issues so far.)