Pcc upper with cam pin recess??

[matt1840]

[enorbit3]

I know spikes makes a 9mm upper. Idk if it's got a cam pin recess tho

[sbo80]

For those kits - there's threads at ARF saying you actually need an upper with an enlarged ejection port, people are using 458 SOCOM uppers, or CMMG does make one specific for it. If that's accurate, I would think a smaller port would be bad. I built a PCC earlier this year and used a 9mm upper, I didn't see uppers that also had a cam cutout as they expect you'd use the typical straight blowback bolt. Plus they wouldn't want anyone building a 223 upper with a 9mm port.