http://www.jouster.com/articles30m1/usmc_rebuilding_m1903.htm
The Hatcher Hole:
Once it was determined that the early numbered ‘03s tended to have brittle receivers (not all of them did, but the incidence was enough to call for a change in the heat treating process in 1918). The so-called double heat-treated (and thus safe) receivers are considered to be 800,001 for Springfield Armory and 285,507 for Rock Island Arsenal (who also interspersed their double heat treated receiver material with a nickel steel version with no clear division by serial number). Much discussion was generated about what to do with the so called “low numbered receivers”… Springfield tried several methods of re-heat treating the older receivers, but no satisfactory solution ever emerged. In short, they were stuck with what they had on hand. A board was convened to come up with a suitable solution. Eventually, they decided to withdraw all the low numbered rifles from service as they were turned in and replace them with the double heat treated variety.
Julian S. Hatcher also recommended the addition of another gas escape hole on the left hand side of the M1903 receiver a bit larger than the small hole on the right hand side. Such a hole would more efficiently allow the escape of gas in the event of some sort of catastrophic failure of the case, or blown primers. This suggestion/recommended modification to the ’03 was well known within the ordnance community, but lay fallow with the Army until October 1936 when all subsequent M1903 receivers would be manufactured with the additional hole. The M1903A3 and A4s were manufactured without the gas relief hole on the right side of the receiver using only the Hatcher Hole version on the left side of the receiver.
Cessation of the manufacture of Service Grade (issue) M1903s ended in 1927, thus the new gas relief (Hatcher) hole had little effect on the final production of the Service Springfield. All rifles produced from 1928 through the end of production were either rifles offered for sale through the DCM, or rifles manufactured for the National Matches. The Marines had taken note of Hatcher’s modification however. The shops in Philadelphia drilled the additional “Hatcher Hole” on virtually all of the rifles that came through (or back through) their shops. In fact, the Marine Corps never made an attempt to withdraw any of the “low numbered” ‘03s from service (unless they were unserviceable for other reasons). When a low numbered gun came through the shops, they totally inspected the rifle, installed a new barrel if necessary, replaced the stock if needed (no new cartouches of course), replaced the bolt with a double heat treated or nickel steel variety, and drilled the Hatcher Hole in the receiver. The rifle was then issued with the proviso that it not be utilized to fire rifle grenades.
While it may be that the Army made similar alterations to their ‘03s, I cannot pin such a conversion down. I have seen many Marine Corps guns sporting the “Hatcher Hole” and replacement barrels. In a Navy ROTC Unit at Tulane University that I used to inspect, virtually every rifle had the “Hatcher Hole” in the receiver, and the Marine Instructor(s) told me that they had received the rifles from the Marine Corps… Absolute proof? Of course not, but it lends credence to the theory for sure…
As a further aside, the Navy ROTC Rifles at Tulane also had their bolts numbered to the receiver with what appeared to be an electo-pencil (or similar). Were all bolts on Marine Corps Rifles serial numbered? Answer – some were, some weren’t. It just depended on the era and what production mode the ordnance folks at Philadelphia were in. Conversely, I have never seen any of the Army Rifle Bolts numbered to the gun, with the exception of the National Match Rifles from Springfield. Even some of the NM Rifles had their serial numbers polished off the bolt for aesthetics by their proud owners. Does that mean that none of the Army guns were serial numbered? Of course not, but a service grade rifle with a numbered bolt would smell suspiciously like a Marine Corps Rifle – absolute? Certainly not, but it’s something for the experienced collector to look for.
