[Worn]

Rather than mill the slide of my gen 2 G19 for a RMR sight, I bought a slide (gen 3) already milled. Using the barrel from my gen 2 G19, I find that the top of the barrel, right at the front of the rectangular part that fits into the front of the slide cutout, it is a tight fit. It rubs a bit going in.

With the original slide, there was a gap of a thousandth or two. With the new slide, none at all and it is an interference fit.

Because of this, when firing, the slide does not always go completely forward after a shot and lock up with the barrel as it should. Sometimes it requires a "forward assist" to get the slide to complete its travel before it can be fired. Other times, although it is not completely locked, the slide is forward enough to fire, but it is a light strike just barely dimpling the primer.

I could try a heavier recoil spring but it seems to me that it should not be that tight.

What do you more knowledgeable folks recommend?

 

[Butch]

During the days they made Gen2's, Glock altered the G19 due to a malfunctioning problem that the NYPD had with their G19's. The alteration was largely in the timing of the lock up/unlocking of the barrel and slide.

If you look at the front of the lock up area of the barrel hoods you'll see that newer one's have a slight bevel where earlier Gen2 G19's do not. See the wear line just to the right of the '9x19' on the top of the front barrel in this pic? That's the bevel.

Is this where you feel the problem is? If so, use of a newer style barrel in the Gen3 slide may be the fix you need.

 

[Worn]

During the days they made Gen2's, Glock altered the G19 due to a malfunctioning problem that the NYPD had with their G19's. The alteration was largely in the timing of the lock up/unlocking of the barrel and slide.

If you look at the front of the lock up area of the barrel hoods you'll see that newer one's have a slight bevel where earlier Gen2 G19's do not. See the wear line just to the right of the '9x19' on the top of the front barrel in this pic? That's the bevel.

No bevel on mine.

Is this where you feel the problem is? If so, use of a newer style barrel in the Gen3 slide may be the fix you need.

Thanks for the info. I have a new, threaded barrel on order. Perhaps that will solve the problem.

 

[Blackhawk556]

this is good info to know. I have a Gen 2 as well so I'm going to have a look at my barrel in the morning and see if it has the bevel.

 

[Worn]

..., use of a newer style barrel in the Gen3 slide may be the fix you need.

I wish. I just installed a new Lone Wolf threaded barrel and it does the same thing. It just does not lock up properly every time.

Like my original gen 2 barrel, it worked fine for just a few shots in the gen 3 slide then began random failures to lock up properly.

Something of note: I'm slow and deliberate when resetting the trigger. Unless in a timed situation, it may be one or two seconds after the shot before I reset the trigger. With this gen 3 slide on my gen 2 G19, sometimes the lockup doesn't occur until I allow the trigger to reset. By that time, of course, all the forward momentum of the slide is lost. There's very little recoil spring pressure remaining at that point to effect lockup.

So, what is preventing lockup until the trigger is reset? This seems like the crux of the matter.

I bought the slide (genuine Glock) fully populated except for a barrel with what I assume are Glock innards; the extractor, firing pun, drop safety, etc. were all there and I didn't have to transfer them from my gen 2. Don't even know if they're compatible.

While I was assured that a gen 3 slide "fits" a gen 2 G19, no one actually said it would work, but it was implied.

Note 2: The only changes I ever made to the original G19 frame are an extended Mag release (Glock) and an extended slide stop (non Glock). I've done nothing with the trigger at all. Those changes were done many thousands of rounds ago and everything worked flawlessly. Always has.

And that's what makes this very disturbing. My G19 has always just worked. My last malfunction was caused by a S&W 40 round that found its way into a magazine and it, not surprisingly, would not chamber the round. (My wife and I (used to) share magazines. I'll say nothing more about that.)

I am unaccustomed to malfunctions of any kind, much less a 50% FTL rate.

Well, I'm going to strip the new slide, removing everything just to see if I find anything obvious.

But a newer barrel (The LWD has the bevel) is not the answer. I need to figure out why the trigger not being reset sometimes prevents full slide travel and lockup.

Perhaps someone who knows a great deal more than I about generational differences can shed some light. Maybe there's something else that needs to be done to make a gen 3 slide work on a gen 2 G19.

 

[Mike-M]

...There's very little recoil spring pressure remaining at that point to effect lockup...

Have you checked that the slide lock is properly installed in the frame, with its groove at the top facing rearward? If it is installed backwards (groove facing forward), the slide/barrel assembly will be prevented from going forward fully into battery.

 

[Worn]

Have you checked that the slide lock is properly installed in the frame, with its groove at the top facing rearward?

Just checked. Yes, it's properly installed, grove at the top and facing rearward. I have not removed it since installation many thousands of rounds ago. Seems like it should have failed with the gen 2 slide as well, it it were the problem.

Any other ideas? I just disassembled both the gen 2 and gen 3 slides. Hard to see many differences. Maybe you have to know what to look for. In any case, I found nothing that appeared out of order.

Maybe I should try the original slide stop. Perhaps there's some subtle difference that deviates just enough from the original to cause this problem on the gen 3 slide only. I'll try switching that out the next time I go to the range.

 

[Butch]

What recoil spring is in the gun? How old is it?

What ammo are you shooting?

 

[Worn]

What recoil spring is in the gun? How old is it?

Original gen 2 spring. As old as gen 2 springs are. Works splendidly with the gen 2 slide.

What ammo are you shooting?

115 gr FMJ.

 

[Butch]

Original gen 2 spring. As old as gen 2 springs are. Works splendidly with the gen 2 slide. 115 gr FMJ.

I'd replace the spring assembly just due to its age...and it may solve the problem too. The recoil spring has to overpower the firing pin spring to close the slide, and having the slide lock up when you let the trigger forward is an indicator of a weak RSA.

Ammo....brand? Factory? Reloads?

 

[mtstream]

I'd replace the spring assembly just due to its age...and it may solve the problem too. The recoil spring has to overpower the firing pin spring to close the slide, and having the slide lock up when you let the trigger forward is an indicator of a weak RSA.

Ammo....brand? Factory? Reloads?

+1 on replacing the spring. Your part # SP 02457.

You should replace due to age but there's also a "Return to Battery" test that may confirm the spring as the issue. This youtube video isn't the best demonstration of how to do it but it's the first that came up in my search
https://www.youtube.com/watch?v=8OBMXbNGfbA

Butch - thanks for the pic of the barrels! That's great information.

 

[Worn]

I'd replace the spring assembly just due to its age...and it may solve the problem too. The recoil spring has to overpower the firing pin spring to close the slide, and having the slide lock up when you let the trigger forward is an indicator of a weak RSA.

Wouldn't a weak spring have the same effect on any slide?

Ammo....brand? Factory? Reloads?

PMC Bronze. new, not reloads. Thousands of rounds of this ammo downrange with no problems using the gen 2 slide.

 

[sasqwatch2]

Wouldn't a weak spring have the same effect on any slide? PMC Bronze. new, not reloads. Thousands of rounds of this ammo downrange with no problems using the gen 2 slide.

Maybe it was because your older slide was well worn and not as tight.

On some of my LWD barrels, I have had to do a little bit a filing to get them to fit. Tolerance stacking will happen.

 

[Worn]

Maybe it was because your older slide was well worn and not as tight.

Wear is always certainly a factor. But the original G19 slide always worked flawlessly, even when new.

On some of my LWD barrels, I have had to do a little bit a filing to get them to fit. Tolerance stacking will happen.

It's not just the LWD barrel that does this. The old barrel has the same problem in this slide.

It seems to me like something in the trigger group is interfering with the slide's return to battery. Maybe that contact is normal and the recoil spring really is weak. I dunno. That's why I'm asking here.

From my perspective, I went from a functioning weapon to a 50% FTL by putting on the gen 3 slide. The first thing I'm going to suspect is the slide. The first fix I tried was a new barrel, as suggested. That didn't fix it. I still, at this point, suspect the slide. But I'll try a new recoil spring anyway.

I'd still like someone to explain what on the frame, besides the rails, contacts the slide. Something in the trigger group seems to be a factor because holding the trigger back, not letting it reset, is what prevents returning to battery -- full lockup. Allowing the trigger to reset frees the slide to return to battery, though it does not always make it.

Where on the slide does this contact take place? I'd like to inspect, possibly polish it.

 

[Worn]

I'd replace the spring assembly just due to its age...

i had a 20 lb spring already so I installed that. It reduced the FTLs but did not eliminate them. So, while replacing the spring is a solution, it is not necessarily the right solution.

Failure to reliably go into battery is the symptom of a problem. What is the problem?

 

[JDG]

I'd replace the spring assembly just due to its age...and it may solve the problem too. The recoil spring has to overpower the firing pin spring to close the slide, and having the slide lock up when you let the trigger forward is an indicator of a weak RSA.

Ammo....brand? Factory? Reloads?

My brand spanking new G26 does this... While dry firing, if I hold the trigger back and slowly rack the slide to reset, the slide wont go fully into battery until I release the trigger. My RSA bad too? It goes into battery easily if I don't hold the trigger back though...

 

[JBP55]

JDG,
If you want to check the trigger reset rack the slide properly.
If you want to check the RSA release the trigger then rack the slide.

 

[JDG]

JDG,
If you want to check the trigger reset rack the slide properly.
If you want to check the RSA release the trigger then rack the slide.

Works fine!

 

[mtstream]

My brand spanking new G26 does this... While dry firing, if I hold the trigger back and slowly rack the slide to reset, the slide wont go fully into battery until I release the trigger. My RSA bad too? It goes into battery easily if I don't hold the trigger back though...

FYI - technically the barrel needs to be pointed up when doing this test so the weight is providing final resistance.

The firing pin spring still engages, even with the trigger pulled, right at the very end when the RSA is as close to full extension as it gets. I've found that gunk (like oil) in the firing pin spring can be just enough resistance to occasionally stop the slide from going into full battery even though the RSA is OK.

Wiping the firing pin/spring with a dry towel and cleaning the channel with dry q-tips is usually enough to correct this. For those who don't know - there is a plastic sleeve inside the channel so you want to be careful to not use any corrosive cleaners in there.

 

[TxGlock9]

If you're having the same problems with a LWD barrel, then I'd suspect the slide is a dud. Where did you get this slide from again?