Firing Pin Protusion problem on 8mm Mauser

[preventec47]

I have 3 Mausers and get 100 percent
success on one with my Czech Mil surp
and the other 2 result in 80 percent
failure to fire. I put 30 pound firing pin
springs on both and no improvement.
I learned the German specs for firing
pin protrusion is .055 to .065 and the
gun smith measured mine at .042
and .047.
Swapping firing pins among guns didnt
help any or any of the other parts.
I am going to try to have .012 removed
from the rear of the grooves on the
firing pin that hold the cocking piece
on and wondered if anyone knows
a machinist with the equipment to
do a real precision job ?

Alternately I would buy a new firing
pin if I could be assured they
stick out longer. There is no way
to tell when ordering new ones and
they are expensive if you can find
em. Any other suggestions?