is this normal for bcg to "release" freely upon takedown?

[bsumoba]

went to take down my M&P15 sport to clean it and everything seemed normal.

went to my other AR, and the bcg just slid right out from the back....strange.... i didn't have to do that with the m&p15 sport? i was thinking to myself, is it less "smooth" finish, while the other bcg is chrome'd out?

looking at the actual functionality, everything is working, locking lugs are locking up (rotating just after it passes the lugs on the barrel extension.

is this normal?

[bsumoba]

The BCG is held into place by the charging handle. It will slide partially out, but if your charging handle is properly locked into place, it should not come all the way out.

If your talking about the BCG sliding partially out, that is normal. The weight on the BCG will pop the dust cover open and (depending on how well its lubed) should cause the bolt to rotate out of battery.

sorry, i need to clarify. when i mean slides out, i mean when i tilt the upper back, the bcg will slide out from the locking lugs and then the charging handle will be the only thing holding it in.

the reason i am asking is my M&P15 sport seems to remain locked in the carrel extension until i give it a little tug and gravity alone will not disengage it. my other AR does not do this and just slides out.

[8mmFMJ]

Is the lock on your handle working?

[m16]

What's the round count on the loose upper?

Check your gas rings.

[ty_w_massey]

Check the hole in the upper receiver where the bolt retainer pin tucks in when the lugs lock. It's the rounded area on the channel for the gas key/charge handle. Mine is warn down so much that when I tilt the upper back the lugs spin and the bcg comes loose. My .50 Beowulf and my M&P upper stay snug. And that wear on the c/h channel was the only difference between the uppers.

[bsumoba]

What's the round count on the loose upper?

Check your gas rings.

Gas rings are worn! about 900 rounds and worn already?

thanks for the advice.

[JDay]

I doubt your gas rings are an issue. In fact your rifle will function without them.

Sent from my SGH-T999 using Tapatalk

[CWDraco]

What's the round count on the loose upper?

Check your gas rings.

yup.

take your BCG and extend the gas bolt. place it bolt facing up on the table. does it collapse? If so the gas rings may need replacing. A BCG should not fall out of the rifle. The charging handle should be needed to unseat and rotate the bolt out from behind the barrel extension lugs.

[m16]

Define "function".

I have done this with an A4, we removed the gas rings one at a time and fired it.

With two gas rings, the rifle functioned normally.

With one gas ring, the carrier came back far enough to eject the spent case but would not strip a fresh cartridge from the mag.

With no gas rings, it wouldn't even eject.

If you have a rifle that cycles normally with no gas rings, it is severely over gassed.

Worn gas rings will most certainly make it easier for the bolt to unlock, and slide out of the receiver.