Dropped BCG, Will not Go Back In

[kmk1012]

Was at the range today and swapped in my 22lr conversion and dropped my BCG from my AR from less than two feet onto cement floor. I visually inspected it and could not see any impact points anywhere. The darn thing will not slide back in now and I'm not sure where to even start. Is it worth stripping it down to see if the bare carrier will go in or just not take a chance and get a new one?

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[DB is Here]

Personally I'd buy a new one, not worth the risk or potential cost of additional damage IMO.

 

[erslll]

I'm going to ask what might be a silly question but.... Is the bolt just pushed back in the carrier so the cam pin won't slide into the upper receiver/charging handle?

 

[titsonritz]

I'm going to ask what might be a silly question but.... Is the bolt just pushed back in the carrier so the cam pin won't slide into the upper receiver/charging handle?

Check this first.

Was at the range today and swapped in my 22lr conversion and dropped my BCG from my AR from less than two feet onto cement floor. I visually inspected it and could not see any impact points anywhere. The darn thing will not slide back in now and I'm not sure where to even start. Is it worth stripping it down to see if the bare carrier will go in or just not take a chance and get a new one?

Definitely, tear it apart and inspect it. Look close at the carrier key. Try to slide it in without the bolt.

 

[kmk1012]

The bolt moves freely and the cam pin (the square thing I think) moves freely. I'll take it to work tomorrow and see if I can strip the BCG down. I haven't had to take one apart before, my friend has done it for me as I was too nervous about messing something up. YouTube will be to the rescue as always for the visual aids.

 

[erslll]

The bolt moves freely and the cam pin (the square thing I think) moves freely. I'll take it to work tomorrow and see if I can strip the BCG down. I haven't had to take one apart before, my friend has done it for me as I was too nervous about messing something up. YouTube will be to the rescue as always for the visual aids.

Yes, but when you are trying to insert it into the upper, is the bolt pulled out of the carrier or pushed in? It needs to be pulled out.

 

[kmk1012]

I'm almost wondering if the upper is just too dang dirty after firing several hundred 22lr's through it. Tonight was the last night of my daughter's shooting team practice and was an open family shoot with all types of 22's. The kids definitely put it through the paces. I'm headed to bed now but will look it over more closely in the AM.

 

[kmk1012]

Yes, but when you are trying to insert it into the upper, is the bolt pulled out of the carrier or pushed in? It needs to be pulled out.

Tried both ways, even tried without the charging handle as well-no go

 

[oli700]

something else is up.....unless the key somehow got knocked off center .....other than that if there was a burr on a rail you would see it ......everything else has so much clearance that you would visually see a problem .......super curious. If it dosent slide in the the upper, I dont see how something on the inside of the BCG could cause this. Its an external dimension problem, or internal dimension of the upper, or the charging handle is bent ?

 

[nwslopoke]

This is why everyone needs at least two AR15s. Parts swap and check.

 

[Camelfilter]

Following.

 

[kmk1012]

This is why everyone needs at least two AR15s. Parts swap and check.

I have a couple more I'll try after work too. I looked it over this morning and still don't see any kind of burr on the points that would have contacted the floor. I may just order another one just to be safe. I don't want a slightly out of spec piece wearing the inside of my upper.

 

[ZigZagZeke]

This is why everyone needs at least two AR15s. Parts swap and check.

Thanks! Now I have a reply when my wife asks why I need more than one!

 

[osprey]

Most likely the cam pin is is interfering with the slot it rides in the upper. Before inserting are you sure the bolt is able to travel all the way to the out position thus centering the cam pin in relation to the slot in the upper? When the bcg hit the deck how did it land? Does it start to go in the upper at all or stop right at point of insertion?

 

[Dozer99]

any possibility that the Gas Key has been knocked out of alignment?

On the other hand if it's not fitting, get a new one and use this one as parts (also find out what's out of kilter).

 

[DirectDrive]

any possibility that the Gas Key has been knocked out of alignment?

On the other hand if it's not fitting, get a new one and use this one as parts (also find out what's out of kilter).

#1 suspect
It was mentioned further back, but maybe the OP missed it ?

 

[Member 5605]

unless the key somehow got knocked off center

My thoughts too..

 

[titsonritz]

The bolt moves freely and the cam pin (the square thing I think) moves freely. I'll take it to work tomorrow and see if I can strip the BCG down. I haven't had to take one apart before, my friend has done it for me as I was too nervous about messing something up. YouTube will be to the rescue as always for the visual aids.

It is a simple process and something every AR owner should know how to do. Go to the 1 minute mark of this video.
https://www.brownells.com/guntech/b...m4-disassembly-part-1-4-/detail.htm?lid=16291

 

[titsonritz]

Most likely the cam pin is is interfering with the slot it rides in the upper. Before inserting are you sure the bolt is able to travel all the way to the out position thus centering the cam pin in relation to the slot in the upper? When the bcg hit the deck how did it land? Does it start to go in the upper at all or stop right at point of insertion?

This will be revealed by following post #4.

 

[Martini_Up]

Remove the 22 conversion BCG then try again