I tried switching the nosecones between my 4" Estes V2 and my LOC IV, and they both fit fine. However, my V2 has flown many times and the body tube may have widened up over time. Also, the upper portion of the LOC nosecone is wider than the Estes nosecone to match the thicker body tube. There is a slight overhang compared to the Estes body tube.
Dave