Upper issue

[Delta Duck]

I just put my second AR together. After almost a 5 month wait from RGuns I got my kit in. I had thought I was getting a complete parts kit but the upper had been assembled. Great less work for me but also no chance for me to learn the process by building it on my own. I get the lower put together added the upper and notice the bolt doesnt want to open - I took it off and the same thing it wont open - out of the box there is an issue.
I read online and after seeing that new guns may be a little sticky I pulled a little harder and it opened - when it did a spring fell out and now there is something rattling around inside? I was thinking forward assist but I wanted to ask here in case someone has another idea.
Of course I called RGuns and left a VM. I also emailed and hopefully will hear back. I dont want to have to send it in - it took too damn long to get it.
Thanks in advance
B

[duggan]

How's the BCG look, everything where it should be? Quick way to tell what springs go where is to look at a parts diagram for the upper, that should nail down where the spring came from.

[m16]

Post a pic of the spring.

[Delta Duck]

Spring Pic

It is about 1 1/4 inch long

I looked at the upper parts diagram and see any spring this size?

[m16]

That looks like a forward assist spring, and explains why it was hard to cycle the action.

Someone probably put the spring in front of the roll pin, instead of behind it (if that's even possible).

[biglou]

Take the forward assist apart and then put it back together, then cycle it again and see what happens.

[lwbyo1]

Spring Pic

It is about 1 1/4 inch long

I looked at the upper parts diagram and see any spring this size?

That looks like a mag catch spring.

Check the forward assist . Is it under spring pressure? If not, then they probably put the wrong spring in it.

[Gutpile66]

Could that be the action buffer catch spring?

[DFence]

Could that be the action buffer catch spring?

Wtf is a action buffer catch spring??

[steelheadmike]

Wtf is a action buffer catch spring??

Buffer detent spring maybe.

[steelheadmike]

So the bcg won't come out of the upper when you have it detached from the lower? Where's the rattle?

My first thought was you may some how snapped off your buffer detent but if the bcg won't come out of the upper when you have it detached, it kinda throws my theory out the window.

[lwbyo1]

It's not a buffer retainer spring.

The buffer retainer spring is shorter, narrower, has more coils and the coils are compressed closer together.

It looks like a mag catch spring.

[DFence]

How about a pic if the whole gun??? Pretty vague with your problems.

Not knowing what you have and don't have assembled isn't helping.

[DFence]

Buffer detent spring maybe.

Possibly. But parts are known as their parts. Not make believe nomenclature