According to the Federal chart (that and a dollar will get ya a coffee) if sighted at a 150 yard zero its dead on at 200 however the bottom does fall out of it shortly thereafter. Id say MM300 is pretty close here. Keep in mind that for this set up you are 5.8 inches high at 100, dead on at 200 and (get this) 23 inches low at 300..lol. The 45-70 wasnt ever intended for long range use even though it has been used very successfully at long range...ask a buffalo . Id say James and a couple of others could probably tell ya its effectiveness also. Remember this is one of those rounds that was obsolete a 75 years ago but it does a darn good job and manages to stick around even with all the new rounds out today.