80% AR Lowers

[Scar13]

Maybe someone can answer this question on building my own AR lower; While drilling and filing my own AR lower, do I need to leave metal where the so called California bump is near the selector area of the cavity,or can this area be filed flat. The bump is also know as the anti machine gun parts bump.

[Spoilerv2]

Are you talking about the rear shelf?

My Palmetto lower doesn't have it but my older Aero lower does.
I dont think it matters.

Btw, these are not my lowers. Got the pic from google.

[strongpoint]

You asked this question and got an answer in a different thread already.