I spend this afternoon putting together my latest AR15. It's an Alexander Arms 6.5Grendel receiver set, Alexander Arms 6.5Grendel mid length barrel, Alexander Arms 6.5Grendel bolt, an Adams Arms mid length piston system, a lower parts kit and a carbine stock kit. Everything seems to go together pretty well.

I got near the end and realized that I don't have a cam pin, firing pin nor a firing pin retaining pin to go with the Adams Arms carrier. Would I be correct to assume that all of these parts are the same for 6.5Grendel and 5.56x45?

The video that came with the Adams Arms piston kit showed the first step as removing the bolt gas rings. Interestingly, the written instructions omitted this step. I understand that the gas rings are not needed, but would there be a negative side effect if I didn't remove them? It doesn't seem like they'd interfere with anything, but sometimes I don't know as much as I think I do. If there's no negative side effect, I'd prefer to leave them so as not to make a permanent commitment.