Built my 2nd ar15 and this time I went with a slick sided upper. Everything went together well but when I charge it the charging handle and bcg don't go forward. Is there a kind of bcg that only goes with slick sided uppers?

Nope they're the same. Take your thumb in the little cut out in the BCG and us it like a forward assist. If it still doesn't go into battery something is wrong.

Are you saying it won't move forward at all or just won't go into battery?

If you used an Anderson slick side "lightweight" sport upper these are pretty thin on the receiver walls.


When you torqued the barrel nut is it possible you warped the receiver cause the BcG to hang up???

None of it will move forward. Bcg or handle. If I can't figure it out I will go with a regular upper. Probably should have from the start.

None of the missing parts on the slick side upper would restrict forward movement of the charging handle or BCG .

So if you swap uppers and your BCG or charging handle are out of spec or incorrect then you'll be in the same situAtion.

You have any other ar15 that are operable that you can confirm with a separate BCG and CH that it is the slick side upper?

Don't take offense to this - I've seen it happen and may or may not have done it myself. Could the buffer and spring have been left out? That would definitely prevent the BCG and charging handle from moving forward on their own.

I do have other AR's and will try switching them out. And yes, the spring and buffer are in there.

Also check the alignment of the gas tube

Make a eraseable mark on the outside of the receiver where the gas tube ends and see if the BCG with the bolt removed stops at the mark.

If the barrel nut is pushing the gas tube to the side it will contact the carrier key and halt movement

Forget the spring in the bolt release? Just guessing. Does it do that with and without an empty mag in?