Gap between stock and receiver

[moopey]

Hey everyone. I unpacked my new 9" Ace stock and lined it up with my receiver to take a picture and noticed there is a gap between the stock and the receiver. What is the part called that needs to be installed in this location?

 

I'm still waiting on a buffer tube, buffer, and spring from Heavy Buffers. Would the part be included with the buffer? Thanks everyone!

 

 

[blue109]

There will be a small lip on the extension/buffer tube that will fill that gap. No worries!

[moopey]

Awesome. Thanks Blue109. This is my first build so I'm sure I'll have some easy/stupid questions. haha