Thanks for the help, guys.  I did take the barreled action out of the stock and removed the side plate.  Everything seems to be fine.  Tried it again with 5 cartridges--now the first cartridge will feed but not the other four.  Do you suppose I have them  (the bullets-Lyman 311284) loaded out too long?  The OAL of the cartridge is 3.185.  And for the life of me I cannot see that the magazine cutoff has any effect in either position.  If I insert the round into the chamber the extractor will not engage--as I said in my original post I have to make sure the bolt is all the way back--the pin on top of the extractor in the groove at the rear of the receiver--and then make sure that the cartridge rim is under the  extractor hook before chambering the round.