3.5 Connector review (Glock)

[Edmond]

A Glock pistol with the 3.5# connector and otherwise stock, will have a trigger pull weight of about 6.0 pounds

Chris,

I'm curious as to how those numbers are calculated out. I've always read those numbers but I've never fully understood how it breaks down.

I have a Glock 3.5# in my G30 and it is smooth. Is it as smooth as my P229 or my P2K? No but compared to the Glocks that the other guys carry in the office, mine is one of the smoothest.

 

[MTMilitiaman]

Chris, and those who know

What does increasing the striker spring strength do to the trigger pull?

My Glock 20 is running pretty much stock, except for the KKM and a 25-cent trigger job. It was a very light polishing that made very little difference in the trigger pull, but all I really wanted was an excuse to detail my Glock. I am planning on putting a 22 pound recoil spring on a SS guide rod with the hopes of improving reliability with hotter loads, and maybe finding some of my brass.

I've been told that increasing the striker spring weight may also increase the trigger pull. So if you put in a stronger striker spring with a lighter trigger spring, does it even out or is this a potentially bad idea?

 

[RyanM]

Increasing striker spring strength will increase the trigger pull. I think it increases the takeup more than the break, but I've never actually used a scale to check. My G23 has an increased striker spring. I guess I could tear down the gun and swap springs, if you're interested.

Also, to decrease trigger pull, you want an increased power trigger spring, and also to drill a hole in your trigger bar. The normal trigger spring pulls back on the trigger, and up. An increased power one would decrease the takeup more than the break, since it would be pulling up harder as well as back. Drilling a hole above the normal trigger bar hole and attaching the spring there makes it pull up less hard, evening things out. It's supposed to be great for removing the transition between takeup (just moving striker) and break (moving striker and also lowering cruciform). It's extremely hard to do though, unless you've got a drill press.

Current mods:
TIG welded feed ramp, fully supported chamber (shouldn't affect trigger)
Striker hood machined off at 45 degree angle
Polished internals
3.5# connector
Machined trigger bar tab (part that hits the connector) to eliminate overtravel

Everything measured at the middle of the trigger. Also the trigger bar tab, side of the frame, and connector were bone dry since that's easier than trying to keep it consistently lubed while taking the thing apart over and over.

-------Wolff 6 pound increased power striker------------

NY-1 trigger spring housing only (no coil spring):
takeup 5 pounds, break 7 pounds (what I leave the gun at)

No trigger spring(trigger must be held to rear while racking slide to reset):
takeup 5 pounds, break 6 pounds (best feeling, but holding trigger while racking slide is a no-no; grinding down NY-1 housing until it pushes with the bare minimum resistance to reset the trigger may get similar results)

Standard trigger spring:
takeup 4 pounds, break 5.5 pounds

I'd like to be able to test the standard trigger spring in a raised hole, but the darn Glockmetal they use in these things is the hardest stuff in the universe. I've gone through 3 drill bits (2 cobalt, 1 titanium, low speed with lubricant) and they've barely made a dent in this thing.

NY-1 normal trigger spring with spring:
takeup 6 pounds, break 8.5 pounds (increased takeup is from friction from the spring housing shoving against the trigger bar)

------standard weight OEM striker-----------

Ouchie finger time. Man, I hate changing striker springs. If I lose those darn spring cups, I'm going to be mad.

Whew, that was gratifyingly uneventful. The gun now makes its old "clack" noise, instead of the "clonk" of the Wolff spring.

NY-1 housing only:
takeup 4.5 pounds, break 7 pounds

No spring:
takeup 4.5 pounds, break 6 pounds

Standard spring:
takeup 3 pounds, break 5.25 pounds

NY-1 entire thing:
takeup 5 pounds, break 8.5 pounds


So if you're going for a smooth trigger pull with minimal transition between takeup and the break, an increased power striker spring is good, and an increased power trigger spring plus a raised hole would be even better. If you're going for a "crisp" trigger, I suggest filling the gun with sauerkraut.

I may be willing to do the same tests with a 5.5# connector, if you pay me money or gun parts or something. Glocks may be easy to detail strip, but it was still kinda time-consuming.

I did try the 5.5# connector with standard springs (both) out of curiousity, and ended up with 3 pound takeup and 7 pound break. Yuck.

 

[MTMilitiaman]

Interesting. Thanks Ryan.

I may just get the increased power striker spring and see how I like the trigger before I decide to fiddle with it.

Thanks again.

 

[Serendipity]

I'm not Chris, but, after a couple of million more rounds, maybe I'll be able to shoot like Chris! However, I do know the answers to a couple of questions.

(1) There is no calculation required, regarding trigger pull weight. Just attach your trigger pull gage and let it do its job.

(2) Increasing trigger spring weight will decrease trigger pull weight.

(3) As previously mentioned, increasing the firing pin spring weight will increase the trigger pull weight. Won't have ANY effect on the takeup, as the only spring being compressed during the takeup is the firing pin safety spring. (aided by the strength of the trigger spring)

(4) Glock has relabled their 3.5# connectors as, I believe, 4# or 4.5# connectors, giving a somewhat more realistic trigger pull weight.

 

[RyanM]

(3) As previously mentioned, increasing the firing pin spring weight will increase the trigger pull weight. Won't have ANY effect on the takeup, as the only spring being compressed during the takeup is the firing pin safety spring. (aided by the strength of the trigger spring)

Actually, the firing pin spring does increase takeup, because the striker is moving. Try one of them orange backplates if you don't believe me.

 

[JohnKSa]

Won't have ANY effect on the takeup, as the only spring being compressed during the takeup is the firing pin safety spring.

The takeup is definitely compressing the striker spring. The slide movement does most of the work tensioning the striker spring(assuming the trigger is not held to the rear). The trigger does the rest of the work during takeup.

The firing pin safety spring is compressed fairly late in the takeup--just about the time you're getting to the "break" portion of the trigger pull.

 

[Serendipity]

If the takeup compresses the firing pin spring (get one of them orange slide cover plates if you don't believe me.), then how, on Earth do all us guys who shoot from the trigger "reset" position get away with not compressing the striker spring during takeup? The FACT is that the striker spring isn't compressed until you feel resistance during the trigger pull....not during the initial takeup. The ONLY function of the takeup is to inactivate the firing pin safety. (get one of them orange slide cover plates if you don't believe me.)

 

[RyanM]

*sigh*. How about actually getting an orange plate and looking in the gun while you pull the trigger?

The cruciform pushes the striker back for the entire trigger travel. For the last fraction of an inch, it also moves down. After the striker is released, it travels ahead of the point where the cruciform can move. That means the slide must be racked in order to get the striker hood onto the cruciform again. That also means that the striker hood is in constant engagement with the cruciform, unless the gun is uncocked. And the cruciform moves with the trigger, from start to finish.

Moving the slide makes a little hump on the right side bend the connector, which releases the trigger bar tab (if the trigger is held to the rear) and lets it pop up under tension from the trigger spring. Then the slide typically continues backward until the striker hood passes over the cruciform, pushing it down slightly. Then as the slide moves forward again, the striker is held at the 100% rearward portion of the trigger travel. The trigger bar tab is wedged between the connector and the frame. When you release the trigger, tension from the striker pushes it forward. At some point, there will be a distinct "click" as the trigger bar tab moves out of the way, allowing the connector to spring to its original position and engage the tab again. That is the reset point.

If you actually went out and got an orange plate instead of being ignorant and pulling stuff out of your butt, you'd know exactly how the Glock trigger works.

 

[Serendipity]

I actually do own an orange plate and actually do own a few Glocks, also. The firing pin is half-cocked by the movement of the slide; the rest of the cocking of the firing pin is accomplished after one feels resistance during the trigger pull. How about answering the simple question about how one shoots from the trigger reset position, with NOtakeup? Didn't pull any of this out of my anal orifice; did pull it from my highly gifted organ that rests behind my eyes and between my ears. Thank you for taking time to post those lovely pictures, which, of course, only show a picture of an orange cover plate. Your propensity for posting lovely pictures of orange cover plates is most impressive.

Oh, yeah, real men don't sigh!

 

[RyanM]

Okay, you're obviously lying. Anyone who actually owns a Glock, and actually owns an orange plate, can very clearly see the firing pin move during the takeup portion of the trigger pull, and can easily see the cruciform pop up when the connector moves. All it takes is a Glock, a brain, and working eyes. You're missing one of the three. Put the plate on and look again. It moves during takeup. Everything works exactly like I've said.

 

[JohnKSa]

Serendipity,

When you hold the trigger to the rear, you're keeping the cruciform bar in its rearmost position.

The slide cam disconnects the cruciform bar from the connector and the trigger spring pulls it to the up position. That means that the cruciform bar catches the striker as the slide returns to battery.

In this case (trigger held back), nearly all of the striker compression is performed by the slide action. But it can only happen because you're holding the trigger back.

Regardless of the trigger position, the striker spring is under compression (to one level or another) if the trigger is engagement with the cruciform bar.

Take your slide off and hold it upside down next to your frame positioned front to rear in the same position it would be if it were in battery. It's easy to see that the striker is too far forward for the cruciform bar to engage regardless of the trigger position.

If you try to move it backward with your finger to a position that will allow it to engage the cruciform bar, you will definitely feel that you are fighting the striker spring's resistance. That means that the striker spring is compressed any time the cruciform bar is in contact with the striker projection.

You don't need an orange back plate. I didn't even know they existed until this thread. You can just take your pistol apart and look at how it works.

With the trigger in the forward position and the striker in engagement with the cruciform bar, the striker spring is compressed by about 65% of the total amount it will be compressed with the trigger fully to the rear. In other words, you're not only compressing the striker spring during takeup, it's ALREADY compressed if the cruciform bar is in engagement with the striker protrusion.

Holding the trigger to the rear lets the slide do the work of compressing the striker spring, but the pull weight is still the same--only the amount of trigger travel is reduced.

One more way that you can prove to yourself that the striker spring is compressed when engagement with the cruciform bar is to ask yourself, What causes the trigger to go to the forward position and stay there?

The firing pin safety spring pushes down, not forward, and it only engages the trigger bar if the trigger is mostly to the rear.

The trigger reset spring pulls BACK and up, not forward. The recoil spring doesn't impinge on the trigger at all and neither does the extractor spring. That leaves only the striker spring. It is, in fact, the striker spring that pushes the trigger to the forward position and holds it there. For all practical purposes, the ONLY spring that is being compressed during takeup is the striker spring.

 

[Serendipity]

So much for "The High Road," huh? Nope, I'm not lying...also not lying when I expound that folks who shoot Glocks competitively sometimes disable the firing pin safety by removing all pre-travel with a setscrew. Now that we have this settled, what size targets can you gurus hit with your Glocks @ 100 yds.?

John: Thank you for your pleasant explanation, particularly the suggestion that I take my slide off so that I can see how the firing pin behaves after it's been half-cocked by the action of the slide during shooting.

 

[JohnKSa]

Serendipity,

With the slide off the gun, the striker is not cocked at all. The striker is either resting directly against the striker safety or is protruding slightly from the firing pin hole when the slide is removed from the frame.

You can verify that the striker is not cocked with the slide removed by feeling that there is a tiny bit of slack in the striker.

Pushing the striker safety button will increase the amount of slack and allow the striker to move all the way forward to protrude from the firing pin hole. The striker is not cocked--indeed there is no mechanism to keep it cocked when the slide is removed from the pistol.

You can remove the pre-travel in the Glock trigger with a set screw. In this case, as when the trigger is manually held to the rear during slide operation, the slide does nearly all the striker spring compression since the cruciform bar picks up and holds the striker fully to the rear while the slide moves forward to battery.

Ok, here's another way to see that what I've been saying is correct.

Field strip the gun and replace the slide onto the frame WITHOUT the barrel and recoil spring.

It will slide all the way back with no resistance.

Now, with your finger off the trigger, move the slide forward until it is in the normal battery position. You will note that the trigger resets during the last half inch of slide travel or so.

Now, leaving the trigger in the forward position, move the slide all the way back and then move it forward slowly. When it gets about 1cm or so out of battery, it will meet resistance. That is the striker protrusion engaging the cruciform bar.

Note the position that the resistance begins. Note that pushing the pistol into battery requires fighting the striker spring, and that as soon as you let go, the pistol pops back out of battery under the force of the striker spring. This happens even with the trigger in the far forward position.

Now, move the slide forward to the battery position and HOLD it there while you pull the trigger. It will feel funny, but it won't hurt anything.

HOLD your finger on the trigger to keep it to the rear. Now repeat the test with the slide (move it back and then slowly forward). Note that this time it meets resistance farther back. That's because with the trigger held to the rear, the striker engages the cruciform bar sooner.

You'll also note that holding the pistol in battery now requires more force since the striker spring is compressed farther when the trigger is held to the rear.

At any time during this procedure, you can pull the slide back, turn the pistol over and note that there is still play in the striker--proving that it is not cocked. The only way the striker can stay cocked is if it stays in engagement with the cruciform bar. When it's too far to the rear (or off the pistol) it's not cocked and the striker spring is not under any tension.

Hold the slide in battery position and pull the trigger. This will allow you to remove the slide from the pistol and you can reassemble it normally. If you don't do this, you'll have a very difficult time removing the slide.

Normally, the recoil spring is holding the slide in battery so you can't feel the striker engagement and striker spring compression nearly as easily. Now that you have done it without the recoil spring in place to get the feel for it, you should be able to feel it while cycling the slide even with the pistol normally assembled.

 

[JohnKSa]

BTW, using a set screw to remove all the pretravel has some side effects.

Because all of the safeties and safety features are built into the trigger in such a way that they are fully engaged with the trigger forward and fully disengaged with the trigger moved back to the end of the pre-travel, locking the trigger to remove pre-travel using a setscrew effectively disables all the passive safeties.

As you point out, it disables the firing pin safety. However, it also disables the function of the safety ramp as well as the the trigger safety. In addition, it means the that slide action now fully compresses the striker spring (maybe not fully as in 100%, but I think it's safe to say at least 95%). In other words, it disables just about every safety feature designed into the Glock pistol.

 

[Serendipity]

John,

Thanks for the detailed explanation. Your patience and thoroughness are appreciated. As a practical matter related to the way that I shoot my Glocks, the takeup isn't an issue, as I don't consider the takeup as part of the trigger pull; ergo, the weight of the takeup is irrelevant to my shooting style.

So, when I release the trigger past the "reset" position, after I've held the trigger back during firing, part of the tension is released on the firing pin spring, only to be recompressed when I squeeze the trigger again?

 

[JohnKSa]

Serendipity,

Yes. When you hold the trigger back during firing and then release it to the reset point, you've let off a tiny bit of striker spring compression. Not very much at all, but some.

If you continue to let off the trigger, you're decompressing the striker spring even more.

Basically, if the trigger is allowed to reset to the fully forward position, then pulling the trigger all the way back to the break point compresses the striker spring about 4 to 5 millimeters.

If you hold the trigger to the rear, now you make the slide do ALL the compression (11 to 12 mm) since the trigger bar is being held all the way back as far as it will go (no takeup). When you release to the trigger reset point, some of that compression is lost, but only a very little bit--however, if you were to let it off all the way, you're back to only about 6 to 7 mm of striker spring compression (11 to 12mm of total compression minus the 4 to 5 mm of compression due to trigger takeup).

There is a good bit of confusion regarding the Glock trigger/striker operation since it's mostly concealed when the gun is assembled. It's not a complicated system, but it's not as easy to SEE as the operation of an external hammer system is. It took me a good bit of fiddling around with Glocks to figure all this stuff out--I've never really found a complete and rigorous description of the internal operation anywhere.