Glock burst-fire malf?

[Complication]

I'm on a week-long shooting vacation so I took my Glock and popped in maritime cups to test them out (as it's my carry piece and I didn't want to fool with something that works and that I rely on when I'm out walking about). They worked just fine for approximately 800 rounds. About halfway through the week, when we decided to clean all our guns, my friend wanted to see how the internals of my Glock worked so I went ahead and mostly detail-stripped it--even to the point of popping out the firing pin cups and spring, etc.

The next day we took the guns out and started doing some shooting. I pulled out the Glock, got it on target, and pulled the trigger. Bang-bang. It popped 2 rounds off. We stopped what we were doing and I pulled the trigger again. Bang-bang. Again it fired a 2-round burst. I loaded one round in the pipe and an empty mag and fired a shot then disassembled the gun. The firing pin was poking its head out.

I popped the firing pin assembly out and the cups had separated somewhat and jumped up forward on the firing pin. I shrugged my shoulders, figured I had just been stupid when putting it back together, re-seated the cups, put the gun back together, and headed out on the line. Again it began firing 2-round bursts. Once or twice more I re-seated the cups and it kept burst-firing. After doing that (and firing a few rounds) the cups won't even seat properly anymore (and begin separating and jumping forward a little).

The maritime cups are thinner and a little weaker (it looks) and unfortunately the original cups are home and I can't replace them for a few days to see if that fixes the problem.

So what happened?

I figure the cups were faulty or broke (or I put it together poorly and firing weakened them) and now won't stay seated in the proper location on the firing pin, causing the firing pin to wedge in the firing pin channel and remain exposed in the chamber causing a 2-round burst (the second round somehow forcing the pin back out of the chamber).

I'm hoping replacing the stock cups will fix my issue but I decided to canvass you all and see if anyone has run into this (or a similar) issue with standard or maritime cups and/or what you found the cause to be.

[M4Guru]

I have seen the striker become lodged as you described and fire (only it burned through the whole mag), and I have seen the rear frame rails break off and cause Glocks to go FA as well. I bet yours is a striker issue going off of the above info.

[one]

One went full auto here at our last qualifications. It dumped the entire magazine. I do believe the rear frame rails were broken on that one.

[ilsrwy27]

Might not have anything to do with your problem but did you make sure the end of the spring contacting the cups was mounted at 90 degrees from the point where the cup (halves) contact each other? If the end of the spring is close or coincides with the cup contact point they can actually separate during firing. Maybe they got damaged after being unseated the first time? The reason I'm asking is because your gun started malfunctioning after being disassembled, cleaned and reassembled which seems too much of a coincidence to ignore.

[Complication]

Well, the stock cups are back in and the gun seems to function normally dry. I'll be shooting tomorrow so we'll see if I didn't fix the problem.

I'm betting money I cocked up the seating of the maritime cups and shooting damaged them further. Hopefully I'm gtg now (though I'll be carrying my CZ until I can confirm :().

[HisDisciple]

How worn is the trigger bar/connector? Have you touched the connector at all?

[2238945]

Check your striker safety block spring, I had one that kinked once and was having burst fires, until I replaced that spring.

[Complication]

Except for the cups, everything looks and feels good. Nothing is visibly worn down and the springs look and feel just as solid as on day 1 (at least as far as I can tell). The gun's only about 3-4 months old and can't have much more than 2,000-2,500 rounds through it. It gets a thorough cleaning every time I take it out and except for when I first brought it home and this past week, I've kept to field-stripping it so it's not like I **** around with any of the assemblies..

[GermanSynergy]

OP,
I would strongly suggest having your Glock pistol inspected by a certified armorer prior to using it again. In it's current state, and given that this is your carry piece, it is a huge liability/safety issue.

[Alpha Sierra]

Being new to Glocks, I just researched what maritime spring cups are and why they exist.

For the life of me I cannot understand why would anyone not intending to fire that pistol underwater would even bother with them.....

Is this just another part to have on your gun because the cool guys have them?

[Complication]

You should go ahead and read this thread:
https://www.m4carbine.net/showthread.php?t=56592

I bought them because (assuming there's no downside) there's absolutely no reason to limit the capabilities of your gun just because the parts didn't come stock--night sights didn't come stock on my Glock either. It's kind of silly to think tiny 0.1 oz pieces of plastic that even the owner will ever see once a year are a "cool guy" piece of gear.

They worked until I f'd them up--but I tried out a piece of gear (in a test environment) and made the personal choice that it wasn't worth the hassle. If that's "cool guy," so be it. I think it's smart gear selection.

[Alpha Sierra]

You should go ahead and read this thread:
https://www.m4carbine.net/showthread.php?t=56592

I bought them because (assuming there's no downside) there's absolutely no reason to limit the capabilities of your gun just because the parts didn't come stock--.
Whatever. Being able to shoot underwater is pretty low on my mission profile.
I

[Complication]

Whatever. Being able to shoot underwater is pretty low on my mission profile.
I


You should go ahead and read this thread:
https://www.m4carbine.net/showthread.php?t=56592

Here's a hint: I didn't buy them to be able to shoot under water.

[Robb Jensen]

I'd recommend inspecting the striker, FP safety and trigger bar and their related springs.

On the old pre-upgrade (black parts) the FP safety would sometimes get a huge burr on it and would stay in the up position and would not allow the striker to fully reset.

Glock on the upgraded parts redesigned the interface of the striker and FP block so that this doesn't happen, they also beefed up the spring rate of the FP safety.

[Complication]

I'd recommend inspecting the striker, FP safety and trigger bar and their related springs.

On the old pre-upgrade (black parts) the FP safety would sometimes get a huge burr on it and would stay in the up position and would not allow the striker to fully reset.

Glock on the upgraded parts redesigned the interface of the striker and FP block so that this doesn't happen, they also beefed up the spring rate of the FP safety.

Good to know.

Also should have added this was a Gen3 G19.

[Robb Jensen]

Good to know.

Also should have added this was a Gen3 G19.

I'd do a through cleaning and inspection of those parts I mentioned. FWIW Titanium strikers is Glock are pretty famous for this too.
Do a compete inspection and replace any parts that seem burred heavily (usually the striker and/or FP safety). Be sure that the FP safety spring is actually attached to the FP safety I've repaired many where non-armorers home-smithed their guns and mashed the spring and it didn't allow the FP safety to work correctly.