TooTaxed
Member
I have an early Colt SP-1 CAR-15, 1:14" twist, and would like to get an upper that would allow me to use bullets heavier than 55-gr.
Are there any pitfalls in getting a Rock River A4 kit for this early collapsable stock lower? I assume I would need an adapter pin...
Any appreciable difference between 18" and 20" bbl lengths? Chrome-moly HBAR and air-guaged stainless steel?
Are there any pitfalls in getting a Rock River A4 kit for this early collapsable stock lower? I assume I would need an adapter pin...
Any appreciable difference between 18" and 20" bbl lengths? Chrome-moly HBAR and air-guaged stainless steel?