Let's talk about Drop Safety function

[glockrocker]

There is a lot of talk about eliminating pre-travel in glocks. There are different methods for eliminating the pre travel, but one thing seems to be consistent if I understand it correctly. When a glock is loaded and ready to fire, the left arm of the cruciform rests on a ledge within the trigger housing. As the trigger is pulled, the cruciform drops off of the ledge allowing firing pin to move forward. This is how the drop safety is designed to work. As long as the cruciform is resting on the ledge the gun can't fire. To eliminate pre-travel (irregardless of which method is used) the trigger assembly must be moved rearward which results in the cruciform resting closer to the edge of the ledge in the trigger housing. There is a point when the trigger assembly can be moved too far (ALL pre-travel eliminated) and the cruciform will be extended beyond the ledge (see stage 2 of the attached diagram) effectively defeating the drop safety. The firing pin safety COULD still be intact, but in the event of a dropped gun, the impact could depress the firing pin safety plunger as well as the trigger safety. Glocks were designed so that all three safeties would work INDEPENDENTLY of each other. Am I wrong?

Here is how I check to see if my drop safety is working:

Remove the slide.

Push the trigger bar forward until the trigger safety engages the frame and stops.

Push down on the cruciform (the metal at the very back end of the trigger).

If the cruciform stay’s up then the drop safety is working.

If you remove to much pre-travel and defeat the drop safety then the trigger bar (cruciform) will go down and then you rely on the firing pin safety. This is assuming that other parts of the trigger bar have been properly modified so that the firing pin safety plunger in not depressed prematurely.

ALL of the competition triggers in the glocks I have owned have had three fully functional safeties and passed the above test. I have seen first hand an aftermarket glock trigger that fails the above drop safety test. I will not say who made it because this is not a flame. The manufacture of this trigger stated to the buyer that all safeties would work. There was next to NO pre-travel in this trigger and the drop safety was defeated.

I am in possession of the above trigger and over the next couple weeks am going to try and prove (in a controlled environment) that impact will fire a glock with this trigger installed. My sole intent and purpose is to inform as many people as I can about this for safety purposes. I believe that it is a matter of time before something bad happens with this practice. Eliminating SOME pre-travel is safe if done by someone who knows what they are doing. Pushing it too far is a disaster waiting to happen. Please, if you are uncertain whether or not your drop safety works, check it.

Also, if anyone has theories to the contrary I would love to hear them.

Shoot Safe.

Drop Safety Diagram

[Jman]

Very well stated. What the he!!, is their something in the Bella Vista, AR drinking water? You got some people there who know "Tupperware". I should edit my recent posts that describes the Vanek newest kit. It should read "no perceived pre-travel". It's there, but hardly perceptible.

Jim M

[P.E. Kelley]

Well explained.

Thank you for your efforts mister! Please continue and report.

Patrick

[itchy]

Very nice explanation.

I'm no rocket scientist, but isn't it impossible to eliminate the "pre-travel" out of a striker fired gun? Or should I say, "safely" remove the pretravel. I can see in a 1911 how the pretravel is eliminated, since the hammer is already cocked. But in a Glock, the act of pulling the trigger actually is the "cocking the hammer" portion of the firing sequence. Are people comparing "removal of pretravel" to "removing the stacking feeling in the trigger"?

I shot one of Rob Leatham's XDs in a class and his trigger had very little "total travel" distance. It felt like it only moved about 1/3 the distance of my Glock's trigger. I'm pretty sure this isn't the same trigger you get when you pick up an XD from the store. It was pretty darn close to a 1911 trigger. But then again he's a professional.

Seiichi

"confirmed trigger slapper"

[boz1911]

Please keep us updated. Nice job and appreciate the effort.

[mscott]

This could be interesting. This sort of competition does lead to great ideas and products, but we shouldn't sacrifice safety to make things "better".

[the duck of death]

Edited December 2, 2007 by the duck of death

[SouthpawG26]

It felt like it only moved about 1/3 the distance of my Glock's trigger. Seiichi

"confirmed trigger slapper"

By design, the XD striker is almost fully pre-cocked (the Glock is only at about a third of it's travel), making it indeed much easier for the expert tinkerer to produce a nice short trigger pull.

[Singlestack Wonder]

There is a lot of talk about eliminating pre-travel in glocks. There are different methods for eliminating the pre travel, but one thing seems to be consistent if I understand it correctly. When a glock is loaded and ready to fire, the left arm of the cruciform rests on a ledge within the trigger housing. As the trigger is pulled, the cruciform drops off of the ledge allowing firing pin to move forward. This is how the drop safety is designed to work. As long as the cruciform is resting on the ledge the gun can't fire. To eliminate pre-travel (irregardless of which method is used) the trigger assembly must be moved rearward which results in the cruciform resting closer to the edge of the ledge in the trigger housing. There is a point when the trigger assembly can be moved too far (ALL pre-travel eliminated) and the cruciform will be extended beyond the ledge (see stage 2 of the attached diagram) effectively defeating the drop safety. The firing pin safety COULD still be intact, but in the event of a dropped gun, the impact could depress the firing pin safety plunger as well as the trigger safety. Glocks were designed so that all three safeties would work INDEPENDENTLY of each other. Am I wrong?

You bring up a great point. A lot of tinkerers as well as companies selling "drop-in" triggers state that all safeties are intact. It would be interesting for those with expensive triggers installed that eliminate pre-travel, to inspect their pistol to see whether or not the trigger cruciform is beyond the drop safety ledge on the tigger housing, thereby disabling the drop safety. When we have competitors at our IDPA matches where we are using a chronograph and inspecting the pistols, when we run across a Glock with the pre-travel removed, we check all three safeties. If one isn't active, a FTDR is issued and the competitor is required to fix the pistol before continuing.

[glockrocker]

You bring up a great point. A lot of tinkerers as well as companies selling "drop-in" triggers state that all safeties are intact. It would be interesting for those with expensive triggers installed that eliminate pre-travel, to inspect their pistol to see whether or not the trigger cruciform is beyond the drop safety ledge on the trigger housing, thereby disabling the drop safety. When we have competitors at our IDPA matches where we are using a chronograph and inspecting the pistols, when we run across a Glock with the pre-travel removed, we check all three safeties. If one isn't active, a FTDR is issued and the competitor is required to fix the pistol before continuing.

Does this happen frequently? One or more of the safeties not functioning? I'm curious how big of a problem this is. I wonder if there are people knowingly shooting glocks with a defeated safety or is there a general sense of surprise when this happens?

[Singlestack Wonder]

It happens quite a bit with gamers in IDPA in SSP. They attempt to argue that even will all of the pre-travel removed, it's still a "Safe-Action" trigger pull. We listen, give them an FTDR, and ask them to remedy the problem. Not sure how USPSA feels about removing trigger pre-travel for Production division, but it hardly seems right to allow the practice as the division is designed around double action and safe action pistols which both offer much longer trigger pulls than single action pistols. If they were to work on developing their trigger skills with a Glock, they would find that there is no disadvantage to the Glock's Safe Action trigger vs. a 1.5# single action 1911 trigger.

Edited December 3, 2007 by Singlestack Wonder

[Joe D]

It is pretty easy to determine if the drop safety is functional. One quick check is to look into the mag well. You can see the striker safety plunger. If the little "nub" on the trigger bar is just touching the plunger then the drop safety is functional. When you see the nub resting on the plunger then both safeties are deactivated.

Do you check the thumb and grip safeties on 1911s? I hope you are not just picking on Glocks.

Edited December 3, 2007 by Joe D

[bountyhunter]

I am in possession of the above trigger and over the next couple weeks am going to try and prove (in a controlled environment) that impact will fire a glock with this trigger installed. My sole intent and purpose is to inform as many people as I can about this for safety purposes. I believe that it is a matter of time before something bad happens with this practice. Eliminating SOME pre-travel is safe if done by someone who knows what they are doing. Pushing it too far is a disaster waiting to happen. Please, if you are uncertain whether or not your drop safety works, check it.

A wise man once told me never to worry about the weight of the flea on top of the elephant standing on my foot.

IMHO, the vast majority of "unfortunate discharges" with Glocks are the result of finger twitches on the trigger, not dropping the weapon on it's muzzle..... which, while dangerous, at least sends the bullet downward. Because of that, I think that lightening the trigger and reducing travel distance to break point are vastly more dangerous than marginalizing the drop safety.

Just my opinion

I would not dispute that pro shooters using the guns for competition can operate them safely enough, but the safeties are certainly reduced in effectiveness.

Edited December 3, 2007 by bountyhunter

[bountyhunter]

It felt like it only moved about 1/3 the distance of my Glock's trigger. Seiichi

"confirmed trigger slapper"

By design, the XD striker is almost fully pre-cocked (the Glock is only at about a third of it's travel), making it indeed much easier for the expert tinkerer to produce a nice short trigger pull.

But, the XD (and SIG and Beretta) all use the same basic FP safety design which requires the trigger pretravel to raise the blocking plunger to allow the FP to strike the primer. In guns where the pretravel is greatly reduced, the trigger bar's rearward position is "pre loading" that FP safety plunger making it either completely ineffective or close to being out of the way.... so, that tiny trigger pull distance has a price.

[Singlestack Wonder]

It is pretty easy to determine if the drop safety is functional. One quick check is to look into the mag well. You can see the striker safety plunger. If the little "nub" on the trigger bar is just touching the plunger then the drop safety is functional. When you see the nub resting on the plunger then both safeties are deactivated.

Do you check the thumb and grip safeties on 1911s? I hope you are not just picking on Glocks.

The safety you are referring to is the striker safety. This safety is utilized when the pistol is dropped to keep the potential striker inertia from hitting the primer on a live round. The drop safety is a ledge on the trigger housing that supports the trigger bar cruciform. The trigger must be pulled back a specific amount before it is allowed to drop away from the striker when the connector is contacted. And yes, we check 1911 grip and thumb safeties as well as all other pistol safeties. The rules state that all safeties are required to be functional.

[Joe D]

What I was saying was if you look at the engagement of the striker safety plunger and see that the trigger bar is just touching it then the drop safety will be functional. If the trigger bar is sitting on top of the plunger then the drop safety is not functional.

[Flexmoney]

I had to remove some of the "gamer bickering" that was in this thread.

Folks...leave that crap at the door, or just stay outside.

Kyle F.

Forum Administrator

[rooster]

Sure am glad I found this topic. After reading I went home and checked my pistol, where supposedly all the safeties are supposed to work. I had the trigger assy. With the 2 adjustment screws. Did the test and the cruciform dropped, not much but I began to wonder so I installed another trigger assy, and did the test. We'll now it doesn't move, so now at this point I don,t even think I was on the shelf at all. I was running around with an unsafe gun. But here is the funny part, with the new assy in I dropped about a 1/4 pound pull, I have more pre travel but I got a little better trigger. I bet there are a lot of blocks out there with the same condition.