We are moving forward on the 7.62x39 and .300 blackout uppers as we speak. Our plan was to create a hybrid of the wk180c upper and our own, that would allow these uppers to run on both platforms. We are planning to use our own bolts because we have them in stock already. Unfortunately our bolt does no fit the wk180c carrier. We have no plans as of yet to make 5.56 or .223 uppers for the wk180c because Kodiac and Wolverine have it covered.
I am curios as to the reason you would like a 5.56 aftermarket bolt for the wk180c? you can pm me if you like.
Kevin, RWA