Is this the one you posted about a while back?
If so, maybe the rim is hanging up in the slot that was left when the cutoff was removed for the installation of the peep sight. You might check that - sometimes the slot was filled in by cutting off the "stem" of the cutoff. This problem is less likely in the 1898 due to the shorter cutoff slot.
Then again, maybe the spring is weak and that's why it's having trouble feeding the last round.