I never mentioned Cordite. The V3 used solid rocket propellant (probably double base), which although more stable than Cordite, must still be handled with respect. I learned this firsthand while overseeing a rocket sled test at China Lake in the early 90's. The technicians there told me of an earlier accident where one of the old Zuni rocket motors ignited prematurely when they were installing it on the sled. The poor guy was cut in half by the exhaust plume.
We could debate the potential effectiveness of Germany's V weapons till the cows come home, but the one thing they all shared, other than usually landing "somewhere over there in the general vicinity of the target most of the time", is that they had zero impact on the outcome of the war. Anything more than that is just wild-eyed conjecture.