In his book "Hatcher's Notebook" General Hatcher in Chapter IX (pages 212 to 231) covers all the details of the manufacture of the 1903 Springfield rifle, including "low numbered", "double heat treated" and nickel steel receivers. Inasmuch as he was the officer assigned, in the spring of 1917, to investigate the damage to two rifles which had been furnished to the National Bras and Copper Tube Company to be used in testing ammunition, he was in a unique position to know the procedures then in effect for manufacturing the Springfield rifle.
It is clear from his account that the pyrometers were installed for the first time as a result of his investigation, and that prior to that time no pyrometers were in use.
He says (page 215), "Too much reliance was being placed on the knowledge and experience of the men who heated the receiver and bolt steel in the forge shop.
These men thought that they could tell when a piece had the right heat just by looking into the furnace. They were proud of their experience, skill and ability, and believed that it took years of practice to become expert in judging the forging temperature. They were highly skilled craftsmen, who were jealous of their exclusive skill, and who both hated and feared the new fangled pyrometers which threatened to make useless their special knowledge.
The first step taken by the metallurgists was to install pyrometrs, when it was quickly found that the "right heat" as judged by the skillful eye of the old timers was up to 300 degrees hotter on a bright sunny day than it was on a dark cloudy one. The variation was of course made much worse by the fact that production had been stepped up to such a degree that many less skillful men had to be employed on this and all other critical jobs."
He later states (page 217), "In 1926 a Board investigating this subject took from stock 24 rifles made in 1918 having double heat treated receivers and tested them with results as given below: (The chart indicated that all 24 rifles were tested with 10 70,000 pound per square inch proof cartridges, and one 80,000 pound per square inch proof shot, after which headspace was increased from one to four thousands of an inch (.001"-.004"). Then all 24 rifles were subjected to one 125,000 pounds per square inch proof shot and none of them failed.)
