Without seeing just how "Casual" your first method of measuring was I will not comment on that.
I will say though having used measuring tools, including micrometers, calipers, scales etc on a daily basis for 35+ years an error of .042" (1.170"-1.128") was not a direct result of choosing dial calipers for the measurement.
While we are Bragging, Closest parts I ever had to build had a tolerance of +.00005 -.00000. They were measured on a Browne & Sharpe Super Mic which one looked into a window & watched for a light beam to bend to get consistent pressure on the anvil. Thimble was at least 6" in diameter so even the .0001" (1 ten thousandths inch) marks were around .075" apart.
I have also lapped parts where we had a tolerance of "1" light band. Is that a match??
.042" is near 3/64", I could measure a firing pin hole's spacing closer than that with a Harbour Freight Tape measure.
PS; I'm through patting myself on the back for now, pass the linement Please.
Last edited by 2-piper; 06/05/18 09:59 PM.
