I suspect the bead centered on the vertical line in the bottom of the 7 ring.

That would put the bullets 6 to 6 1/2" above the centre of the bead at 50yards - about right, I would think. IIRC, the Martini I had back in the mid 70's printed about 8" high at 50 yards using a 480gr. PP with 85gr. C&H 3F. The C&H was quite weak, hence the use of 3F.