Remi,RIA
http://vishooter.home.att.net/m1903.html
"319921 (First SN of August, 1918 - Hatcher's Notebook pg 220) First Nickel Steel (NS) receiver made soon after"
http://www.snipercountry.com/article...fieldm1903.asp
http://74.125.95.132/search?q=cache:...&ct=clnk&gl=us
1918-257062-326935
1919-326936-348414
TOTAL: 346000
Introduction of improved heat treatment at SN285507.
Introduction of nickel steel at SN319921.
F. Guffey