I bought my AR15 used, and it came minus the buffer retainer spring. Having just gotten a new spring, I am assuming that I'm somehow installing this incorrectly. The buffer retainer gets jammed into the bolt every time I assemble it. Is the buffer retainer supposed to sit against the front of the buffer? Is it supposed to be fixed into the buffer retainer hole somehow? It comes out freely.

Thank you.
GoodFellas.

You need to unscrew the buffer tube (the tube that the buffer rides in) a ways. Install the buffer retainer spring and the retainer over that...push it into the hole, screw buffer tube back on all the way...the tube will go over half of the retainer, holding it in place.

That makes perfect sense. Guess I just need to wait till my stock wrench comes in. Thanks.

It will be 1.5 weeks till my stock wrench comes in. Is the rifle operational without the buffer retainer? It appears the only function is to prevent the buffer from springing out during breakdown.

Thanks,
Goodfellas

Quoted: Is the rifle operational without the buffer retainer?

Yep. So long as you remember it's missing when breaking open the rifle, you're good to go.