I have a standard, M4 profile 16" midlength, BCM upper with about 300 rounds through it. I have two 5.56 uppers, and want to get rid of one.

I want to trade it for a 300 blackout or a 6.8 spc upper. Would prefer 300 Blackout.

Will +/- cash as needed. If you have a 6.8spc with BCG, add in a 5.56 BCG.