butlersrangers wrote on Dec 24^th, 2015 at 5:00pm:

FredC - Your commentary on Springfield Armory threads and Dies is interesting. I assume our U.S. Armories and tooling were influenced by the 'French Arms' we first copied and manufactured.

I just pulled the original screws out of my dad's 1917 Enfield and they have 30 threads per inch with the same rounded crests and roots. The flanks have the now standard 60 included angles and not the earlier 55 Witworth angles.
So you may very well be correct that the 25 TPI is French. I got mixed up because the Brownells catalog makes reference to one other rifle having the same pitch as the Krag, must have been the 03 Springfield.
It is funny that the French and English gun makers would have used such odd ball thread pitches. Most small and medium size lathes have an 8 pitch lead screw. If the thread TPI that you are cutting will divide into 8 evenly you do not need to look at a thread leadscrew dial as you can start the feed at any place. The 24 AND 32 pitch screws of the American unified system would have faster to make before screw machines became readily available.