Your individual calculations using ChairGun are fine.... but you keep arguing that from those two you can get data that is correct at any distance or velocity.... That is not correct, and I have tried to explain that several times, without success.... I suggest you do some more research, as I simply don't have the time to continue trying to assist you.... Good Luck....Bob
Apparently answering the question as completely and politely as I can, many times, doesn't either.... rws45user has his own ideas, that conflicts with reality, so who am I to continue to try and change that.... "FULL BABY" and "no answer at all"?.... You obviously didn't read my FIRST reply, where I answered the OP's question as completely as possible.... back in 2015 when the thread started.... as to being a "douche bag".... …. I guess you never got tired of trying to help someone who just wanted to argue?.... I have no responsibility to keep trying to do that, thank you.... I gave him many answers, he just didn't want to hear them....Bob, I do apologize for not being clear who I was answering, you may have thought my last answer was directed at you, I assure you it was not.... The BC at 870 is probably in between 0.032 and 0.040, depending on what gun.... Bob