Charging Handle Only Locks Half The Time

JohnFireingLine · October 13, 2018, 08:01 PM

I broke down my Ar-15 and gave it a good cleaning after taking it to the range (not my first time). Upon reassembling it it would appear that that charging handle is not locking in place as easily as I remember. If I don't rack it smartly it just springs back but doen't lock. I do not remember this happening before.

Should I get it replace? The charging handle latch looks a tad worn. But does that mean Id have to replace the entire upper to fix that?

And I guess I better ask... I presume that the charging handle will hit me in the face if I fire the gun and it's not locked. Am I mistaken?

Mobuck · October 13, 2018, 09:20 PM

"The charging handle latch looks a tad worn. But does that mean Id have to replace the entire upper to fix that?"
The charging handle is a separate interchangeable part but if it was working, cleaning shouldn't have changed that.
Is the bolt going fully into battery? If not, the CH won't latch. If the problem showed up AFTER re-assembly, most likely you forced debris into the locking lug recesses preventing the bolt from rotating into battery or your cam pin is binding in it's track with similar results.

raimius · October 14, 2018, 03:22 AM

Can you describe where the worn section is?

This is the piece you are describing, correct?

JohnFireingLine · October 15, 2018, 11:46 AM

I think Mobuck had it right I broke the rifle down again an as it turns out there was a very tiny (barely noticeable) spot of grim under the charging handle. Just enough to make the smooth metal ever so slightly rough. I literally mean "slightly". I scrapped it off with a plastic pick and made everything smooth. I added some more lubricant and now everything is working fine.

Go figure. I kinda thought my Ar was a bit more resilient then that. I will take better note of the smoothness of these surfaces in the future.

Mobuck · October 16, 2018, 06:43 AM

I'm not at all sure we addressed the entire question. Finding a "bit of grim" on the CH would not seem to be the cause of the malfunction originally described. It seems you've got things working but my concern is the "fix" doesn't match the problem.
Back to the start, was the "CH not latching" because the BCG wasn't fully forward or because debris was preventing the CH from latching?
Next time you handle your AR, try cleaning the bolt lug recesses and see what comes out. My AR's are carried daily and sometimes w/o a muzzle cap so I find dead flies, bits of vegetation, and such that have ended up down the bore and into the barrel extension. When this builds up to a certain level, the bolt doesn't fully engage unless it's hammered home from a fully retracted position.

JohnFireingLine · October 16, 2018, 08:34 PM

What was specifically happening: was that the act of racking the charging handle and locking it required me to be sure that I pulled it all the way back and release it smartly in order for it to do so (lock). Prior to cleaning the gun, it just locked very easily without me having to think about it even from the 3/4 or 1/2 position. I could even be careless with it and it would still snap into place. It just worked.

After breaking down the gun and racking the charging handle the first time I noticed that the latch did not lock. I performed my usual racking of the charging handle repeatedly only to find that it was now only locking about half the time... and I now had to be 100% sure to pull it all the way back and release it smartly as if I would a bow and arrow.

The black "soot" was located directly under what (I think) is the gas tube. Charcoal -like buildup that somehow got missed by my brush and CLP. I took a plastic pick and scraped it off and this created a smooth surface for the charging handle to slide on. Now things are back to normal. I also added more lubricant and will probably keep the gun a bit more lubricated from now on if it is going to behave in this way. All in all id say this is a somewhat strange occurrence as I always keep my gun very clean.

Anyway, thank you for taking the time to help diagnose this issue. I do appreciate it

stagpanther · October 17, 2018, 12:49 AM

Just behind the charging handle on the lower receiver are there any signs of wear? Occasionally in builds the lower of one manufacturer might have a higher rear buffer tube collar than another manufacturer's upper will allow for a "straight back" path of the charging handle--so that when you charge the handle it is forced to ride at a slight angle (a stock on the buffer tube can also cause this if it is close to the receiver). I've seen this happen occasionally--when you charge manually or drop the bolt carrier from the bolt catch the handle will close but the latch tooth may not engage the upper's notch--so when you fire the handle might actually recoil back.

Nanuk · October 17, 2018, 05:55 AM

You should be able to lock the bolt to the rear and then slide the charging handle in to lock. Sometimes with new guns these parts need to wear in a little so they work smoothly.

Mobuck · October 17, 2018, 05:57 AM

OK, now I can better understand where you found the carbon and how that could have been the hang-up. Keeping things wet is good if you're doing range work.

fl_rich · October 17, 2018, 05:13 PM

My experience has been the tighter the tolerances are when the component(s) are manufactured the more time is required to "break in" the rifle. Tight tolerances mean things can not completely seat when a little grime is thrown into the equation

October 13, 2018, 08:01 PM	#1
JohnFireingLine Junior Member Join Date: October 6, 2018 Posts: 7	Charging Handle Only Locks Half The Time I broke down my Ar-15 and gave it a good cleaning after taking it to the range (not my first time). Upon reassembling it it would appear that that charging handle is not locking in place as easily as I remember. If I don't rack it smartly it just springs back but doen't lock. I do not remember this happening before. Should I get it replace? The charging handle latch looks a tad worn. But does that mean Id have to replace the entire upper to fix that? And I guess I better ask... I presume that the charging handle will hit me in the face if I fire the gun and it's not locked. Am I mistaken?

October 17, 2018, 12:49 AM	#7
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,772	Just behind the charging handle on the lower receiver are there any signs of wear? Occasionally in builds the lower of one manufacturer might have a higher rear buffer tube collar than another manufacturer's upper will allow for a "straight back" path of the charging handle--so that when you charge the handle it is forced to ride at a slight angle (a stock on the buffer tube can also cause this if it is close to the receiver). I've seen this happen occasionally--when you charge manually or drop the bolt carrier from the bolt catch the handle will close but the latch tooth may not engage the upper's notch--so when you fire the handle might actually recoil back. __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*

October 17, 2018, 05:55 AM	#8
Nanuk Senior Member Join Date: January 2, 2005 Location: Where the deer and the antelope roam. Posts: 3,082	You should be able to lock the bolt to the rear and then slide the charging handle in to lock. Sometimes with new guns these parts need to wear in a little so they work smoothly. __________________ Retired Law Enforcement U. S. Army Veteran Armorer My rifle and pistol are tools, I am the weapon.

October 17, 2018, 05:13 PM	#10
fl_rich Senior Member Join Date: October 27, 2015 Posts: 103	My experience has been the tighter the tolerances are when the component(s) are manufactured the more time is required to "break in" the rifle. Tight tolerances mean things can not completely seat when a little grime is thrown into the equation __________________ Many things others should worry about....

October 13, 2018, 09:20 PM	#2
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	"The charging handle latch looks a tad worn. But does that mean Id have to replace the entire upper to fix that?" The charging handle is a separate interchangeable part but if it was working, cleaning shouldn't have changed that. Is the bolt going fully into battery? If not, the CH won't latch. If the problem showed up AFTER re-assembly, most likely you forced debris into the locking lug recesses preventing the bolt from rotating into battery or your cam pin is binding in it's track with similar results.

October 14, 2018, 03:22 AM	#3
raimius Senior Member Join Date: January 27, 2008 Posts: 2,199	Can you describe where the worn section is? This is the piece you are describing, correct?

October 15, 2018, 11:46 AM	#4
JohnFireingLine Junior Member Join Date: October 6, 2018 Posts: 7	I think Mobuck had it right I broke the rifle down again an as it turns out there was a very tiny (barely noticeable) spot of grim under the charging handle. Just enough to make the smooth metal ever so slightly rough. I literally mean "slightly". I scrapped it off with a plastic pick and made everything smooth. I added some more lubricant and now everything is working fine. Go figure. I kinda thought my Ar was a bit more resilient then that. I will take better note of the smoothness of these surfaces in the future.

October 16, 2018, 06:43 AM	#5
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	I'm not at all sure we addressed the entire question. Finding a "bit of grim" on the CH would not seem to be the cause of the malfunction originally described. It seems you've got things working but my concern is the "fix" doesn't match the problem. Back to the start, was the "CH not latching" because the BCG wasn't fully forward or because debris was preventing the CH from latching? Next time you handle your AR, try cleaning the bolt lug recesses and see what comes out. My AR's are carried daily and sometimes w/o a muzzle cap so I find dead flies, bits of vegetation, and such that have ended up down the bore and into the barrel extension. When this builds up to a certain level, the bolt doesn't fully engage unless it's hammered home from a fully retracted position.

October 16, 2018, 08:34 PM	#6
JohnFireingLine Junior Member Join Date: October 6, 2018 Posts: 7	What was specifically happening: was that the act of racking the charging handle and locking it required me to be sure that I pulled it all the way back and release it smartly in order for it to do so (lock). Prior to cleaning the gun, it just locked very easily without me having to think about it even from the 3/4 or 1/2 position. I could even be careless with it and it would still snap into place. It just worked. After breaking down the gun and racking the charging handle the first time I noticed that the latch did not lock. I performed my usual racking of the charging handle repeatedly only to find that it was now only locking about half the time... and I now had to be 100% sure to pull it all the way back and release it smartly as if I would a bow and arrow. The black "soot" was located directly under what (I think) is the gas tube. Charcoal -like buildup that somehow got missed by my brush and CLP. I took a plastic pick and scraped it off and this created a smooth surface for the charging handle to slide on. Now things are back to normal. I also added more lubricant and will probably keep the gun a bit more lubricated from now on if it is going to behave in this way. All in all id say this is a somewhat strange occurrence as I always keep my gun very clean. Anyway, thank you for taking the time to help diagnose this issue. I do appreciate it

October 17, 2018, 05:57 AM	#9
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	OK, now I can better understand where you found the carbon and how that could have been the hang-up. Keeping things wet is good if you're doing range work.