The regimental headquarters that has overseen infantry operations in northern Helmand province, Afghanistan, for the last year is headed home. Regimental Combat Team 8, out of Camp Lejeune, N.C., has been replaced in Afghanistan by Lejeune’s RCT-6, said Marine officials in Afghanistan. Like RCT-8, RCT-6 will be based out of Camp Delaram II in northeastern Nimroz province, overseeing operations in Sangin, Kajaki, Musa Qala and other nearby districts. For RCT-8, commanded by Col. Eric Smith, it has been a long deployment in which several units have seen continued combat. Most recently, they included 1st Battalion, 6th Marines; 3rd Battalion, 7th…