Ejection Port Won’t Close - Is this upper out of spec?

[csobrien]

I bought a complete upper a while back. Built it out, did the legal, zero’d it and put holes in some paper. All seemed well.

Now I realize the dust cover won’t close. It seems like the space between the hinge pin and the top of the ejection port is too short. When closing the cover, the rounded part of the detent should hit the top of the ejection port, depressing the spring and allowing the detent to slide into its notch and hold closed. Because there’s not enough space, the edge of the port hits the vertical part of the detent instead of the rounded part so it doesn’t depress and click shut (I’ll add pictures, but it’s hard to show).

Today I replaced the dust cover to see if that was the issue. It’s not. Same problem.

Should I get in contact with the OEM or am I missing something?

 

[greencobra]

I bought a complete upper

if you had to "build it out" im thinking it wasn't complete. every complete upper i've built has the dust cover installed already.

 

[Frizzle Fry]

if you had to "build it out" im thinking it wasn't complete. every complete upper i've built has the dust cover installed already.

You're a smart man to buy them already installed. At the shop we had a brand which I forget now which had no e-clips... spring loaded pins on either end. Manna from heaven.

If I was you OP I'd just sand it down. Shit happens. Does the upper shoot ok?

 

[csobrien]

if you had to "build it out" im thinking it wasn't complete. every complete upper i've built has the dust cover installed already.

It would’ve been more accurate for me to say I built a lower and slapped the upper onto it.

The upper came assembled, dust cover and all.

 

[scatter]

Well your finger is in the way but it looks to me like the forward pivot point of your dust cover hinge pin is either bent, not seated, or your handguard has rotated, raising the pivot point.

Also it looks like your mag release button needs screwed in a bit more. The pin in the center should be flush with the threads on the button.

 

[92G]

Lolz what is the upper receiver?

 

[Frizzle Fry]

Well your finger is in the way but it looks to me like the forward pivot point of your dust cover hinge pin is either bent, not seated, or your handguard has rotated, raising the pivot point.

Also it looks like your mag release button needs screwed in a bit more. The pin in the center should be flush with the threads on the button.

Good catch, wasn't even looking there. Can we get a picture shot from the side and top? Curious to see if the e-clips are in the right place or there at all.

 

[Uzi2]

It will close if you push it closed.

 

[Uzi2]

Good catch, wasn't even looking there. Can we get a picture shot from the side and top? Curious to see if the e-clips are in the right place or there at all.

The clips wouldn't make any difference in the height of the cover.

Any broken in upper receiver will have a wear mark where the cover detent engages the upper receiver.

OP, push that thing closed a couple of dozen times so the parts mate.

Not from the ends either......from the center where the detent is.

 

[csobrien]

Good catch, wasn't even looking there. Can we get a picture shot from the side and top? Curious to see if the e-clips are in the right place or there at all.

 

[csobrien]

The clips wouldn't make any difference in the height of the cover.

Any broken in upper receiver will have a wear mark where the cover detent engages the upper receiver.

OP, push that thing closed a couple of dozen times so the parts mate.

Not from the ends either......from the center where the detent is.

Thank you. In this case (as always) the answer was “use more force.” I had to get on my feet and put about 200lbs on it through my thumb, but it went. Working it closed more and more and it’s getting easier.

I wish I asked here before trying the new cover.

 

[Deleted member 12999]

I smashed mine on something and now it's as useless as it was when it worked fine.

 

[Rob Boudrie]

Thank you. In this case (as always) the answer was “use more force.” I had to get on my feet and put about 200lbs on it through my thumb, but it went. Working it closed more and more and it’s getting easier.

I wish I asked here before trying the new cover.

Did you lube the ball? Be careful about force and check regularly to make sure you are not getting it to close by wearing a groove in the upper where the ball makes contact.

 

[scatter]

Has the cover ever closed or is this a new problem?

I don't see anything wrong with your hinge pin now that you posted the close-ups.

 

[Frizzle Fry]

The clips wouldn't make any difference in the height of the cover.

It would if somebody manged the rod on there, and it's working like a cam to jam it up when it rotates. Seen it a few times.

 

[Frizzle Fry]

Chewed on and a little bent but nothing looks weird.

 

[mac1911]

I bought a complete upper a while back. Built it out, did the legal, zero’d it and put holes in some paper. All seemed well.

Now I realize the dust cover won’t close. It seems like the space between the hinge pin and the top of the ejection port is too short. When closing the cover, the rounded part of the detent should hit the top of the ejection port, depressing the spring and allowing the detent to slide into its notch and hold closed. Because there’s not enough space, the edge of the port hits the vertical part of the detent instead of the rounded part so it doesn’t depress and click shut (I’ll add pictures, but it’s hard to show).

Today I replaced the dust cover to see if that was the issue. It’s not. Same problem.

Should I get in contact with the OEM or am I missing something?

So the upper you bought was already assembled? If so was the cover closed ?
Personally I would put some oil on it and give it a palm slap closed.

 

[greencobra]

this is crazy, never seen a finicky dust cover unless it had been damaged somehow. gotta be something simple...you'd think.

 

[Broc]

Throw it out.

 

[Uzi2]

Did you lube the ball? Be careful about force and check regularly to make sure you are not getting it to close by wearing a groove in the upper where the ball makes contact.

There will always be a slight groove where the detent contacts on closing.

 

[Rob Boudrie]

There will always be a slight groove where the detent contacts on closing.

Just keep it slight

 

[Uzi2]

It would if somebody manged the rod on there, and it's working like a cam to jam it up when it rotates. Seen it a few times.

That would be a bent rod not turning concentrically. The cover would work with or without clips.

 

[csobrien]

Has the cover ever closed or is this a new problem?

I don't see anything wrong with your hinge pin now that you posted the close-ups.

It had never closed.

Update: It works now. It closes securely after I took Uzi2’s advice to force it shut and then break in the groove a bit. @RobBoudrie, the groove is intact and from what I can tell, doesn’t look overly worn or in danger of not holding. Spring and detent moved reasonably freely on both covers.

Thank you to everyone who helped or tried to help.

 

[chindogg]

I bought a complete upper a while back. Built it out, did the legal, zero’d it and put holes in some paper. All seemed well.

Now I realize the dust cover won’t close. It seems like the space between the hinge pin and the top of the ejection port is too short. When closing the cover, the rounded part of the detent should hit the top of the ejection port, depressing the spring and allowing the detent to slide into its notch and hold closed. Because there’s not enough space, the edge of the port hits the vertical part of the detent instead of the rounded part so it doesn’t depress and click shut (I’ll add pictures, but it’s hard to show).

Today I replaced the dust cover to see if that was the issue. It’s not. Same problem.

Should I get in contact with the OEM or am I missing something?

These are available all over. UTG sells the same thing. The detent is adjustable with an allen key so it should work.

- Strike Industries AR Ultimate Dust Cover with Flag Design - AR15Discounts

The patent pending SI UDC enables users to attach and detach the cover in 5 to 10 seconds with ease (stock dust cover will take more time to remove)! It is

ar15discounts.com

 

[KBCraig]

Throw it out.

Seriously. Unless you're low-crawling through the mud, you don't need a dust cover.

 

[bullseye]

Hammer!

 

[AHM]

Seriously. Unless you're low-crawling through the mud, you don't need a dust cover.

Operating operators have needs.

 

[Bonesinium]

I had one that had problems closing and needed more force than others. It was a disaster. Whenever I shot that rifle, it functioned exactly the same. When I put it away, never exploded or fell apart. On cleaning, it was never packed full of dust. Crazy!

 

[MAGA99]

My only out of spec shit is spikes tactical. PSA does a better job, for real. The detention groove looms a little undercut. Hammer and dremel will fix.

 

[KBCraig]

Operating operators have needs.

Wait... is that the model for Spike's?