The chaotic realities of trench warfare in World War I exposed a persistent gripe with the M1903’s sights: they were hard to acquire in harsh combat environments. While the standard peep sight was very good for static shooting in good light, it would prove difficult to acquire in low light or on the move. This prompted the decision to create a more “combat friendly” sight system for the M1903. The solution would take the form of a thicker front sight blade and larger rear peep, emulating the easy target acquisition of the US M1917 rifle’s sights. The M1917 was used primarily by US Army troops in the war, but also to some extent with the Marines, and was praised for sights US infantrymen found to be superior to those of the M1903. While not a perfect rifle, the M1917 did point out room for operational improvement in the M1903’s standard issue .06 width “#6” sights, and in response the Marine Corps’ .10″ width “#10” sight system was born.
#10 sight system during testing and development at the Philadelphia Depot of Supplies (photos: NARA & Tim Plowman collection)
The unique #10 sight system would serve on Marine M1903s during the interwar years (Ryan Niederman collection).
Developed in 1918, the #10 sight system would include a taller, wider front sight blade, a large, solitary peep on the slide, and a vastly improved, larger front sight cover which no longer restricted the shooter’s field of view. The battle sight zero (BZO) was also changed to what the Marine Corps believed was a more appropriate 200 yards. Although the #10 sight system was designed by the Marines at the Philadelphia Depot, it would be manufactured at Springfield Armory, with an order for 57,000 front sights, rear slide, and sight covers being filled in 1919. While suited very well for the front, it was almost immediately noticed to decrease the accuracy of Marine recruits qualifying for the first time during boot camp at Parris Island. The officers of the rifle range detachment conducted thorough studies on the loss of accuracy compared to the range friendly, production standard #6 sights, but ultimately it was decided that through careful instruction this could be mitigated. The #10 sight system was to stay for the immediate future.
The advent of Parkerizing would dramatically increase finish durability and longevity, with the Marine Corps adopting it following WWI (document: Tim Plowman/NARA).
Sights weren’t the only concern for the Marines following the war as many of their rifles were worn out, particularly the barrels. With corrosively primed ammunition being the standard of the era, the soggy French trenches and subsequent combat duties in Haiti, the Dominican Republic, and sea duty had led to barrels that were in need of replacement and receivers that would benefit from being refinished. In 1920 the Marines took action on both, requesting barrels from Springfield Armory as well as beginning to utilize the Parker process, i.e. “parkerizing” their receivers during rebuild. The increase in finish durability of the newly parkerized rifles was tremendously beneficial to the Marines, as their operation tempo was still much higher than that of the other US service branches.
Marines on patrol and in action in the Dominican Republic and Haiti (photos: NARA/USMC)
By 1926, it was becoming clear there was a problem with the hardness of some M1903 receivers. It was discovered that prior to 1918 armory personnel had forgone using instrumentation when newly forged receivers underwent a heat treatment process, choosing to “eyeball” them instead to judge when they believed the process was complete. Despite their expertise and skill, this impromptu shortcut led to some receivers being improperly exposed to the high temperatures used in the hardening process. Overexposure would cause receivers to become brittle and susceptible to breakage under pressure; conversely not being treated long enough would leave them too malleable, leading to premature headspace wear. The exact degree of the severity of this issue was debated ad nauseam for the rest of the M1903’s service history (and still continues today). More than a few officers and ordnance personnel believed the issue of M1903 receiver breakage was primarily due to faulty ammunition and Springfield Armory exaggerations, as they wanted to keep their armory busy with work during the tight years of the Great Depression. For their part the Marines would waver on this issue and the solutions to it, ultimately never completely pulling pre-1918 production receivers from the line.
Combat action for Marines in Haiti, not long after the cessation of WWI (photo:
In 1926 an exchange program between the Marines and Springfield Armory would commence. The Marine Corps desired loose barrels to procure for overhaul, but Springfield Armory and Rock Island Arsenal would have none available, as their practice at the time was to preassemble barreled receivers which would be swapped as needed during rifle overhauls. It was agreed upon that the Marines would instead send in worn out barreled receivers for a partial credit, and receive a fresh barreled receiver in exchange. As heat treatment issues on M1903 receivers were now being addressed, Springfield Armory would only send the Marines barreled receivers made subsequent to serial number 800,000 or those made by Rock Island Arsenal, as it was initially believed the heat treatment issues did not pertain to Rock Island Arsenal receivers. This plan would be amended before any exchanges took place however, as further examination would find Rock Island Arsenal receivers to be just as faulty, thus updating the exchange policy to deem Rock Island Arsenal receivers under serial number 285,507 as faulty. All Springfield Armory receivers under 800,000 and Rock Island Arsenal receivers under 285,507 (or “Under’s” as the Marines often called them) would be turned in for no credit whatsoever, and would be replaced at cost with an “Over” barreled receiver. Colloquially to modern collectors and enthusiasts, Over and Under receivers are most commonly referred to as high number and low number receivers, respectively. When encountering a Marine rebuilt M1903, the likelihood of finding one in the high number range is disproportionally greater, certainly due to this exchange. At minimum 10,000 barreled receivers were exchanged, with about two thirds of those sent in by the Marines being of low serial number. Unfortunately for collectors, many of the low numbers exchanged would have been veterans of WWI combat, thus reducing the likelihood of coming across a WWI used example today. On top of the exchanges, one auction of an unknown amount of low number receivers was held by the Marine Corps, as indicated by National Archives documentation.
Directive to auction off low number M1903 receivers, referred to the Marine Corps as “Under’s” in correspondence (documents: Tim Plowman/NARA).
Not all low numbered receivers would bear the same fate, as just a year after the barreled receiver exchange program began the Marines terminated it in 1927. Due to a combination of cost concerns and the belief that low numbered receivers would be fine for regular rifle firing duties, the Marines decided instead to recycle all receivers and instead obtain sizable barrel orders, which were now available from Springfield Armory. Between 5,000 to 10,000 barrels a year would be procured for the next five years, allowing the Marines to significantly overhaul rifles that were wearing out. The combination of the late 20s barreled receiver exchanges and subsequent barrel orders are quite evident today, as many USMC M1903s are observed with 1927-1932 dated Springfield Armory barrels.
Rock Island Arsenal M1903 #324219, very likely documented to the Marine Corps Quartermaster in San Diego, where the ongoing process of surveying the rifles of the 2nd Marine Brigade (amongst others from Camp Pendleton) was taking place. A M1903 with serial number 324219 was in fact surveyed by the Quartermaster in San Diego in 1926, however the Marines did not record if a serial number was for Springfield Armory or Rock Island Arsenal rifle, which overlapped each other in serial number ranges. We do know that the Marines received very large amounts of Rock Island Arsenal rifles in the 300k range, and that the Marines did not receive M1903 service rifles until 1910, making this document’s serial number far more likely to be the RIA than the SA rifle (Tim Plowman collection, documentation by Andrew Stolinski & Archival Research Group).
The Marines’ fresh supply of overhauled M1903s would not stay new for long, as ongoing “banana war” conflicts saw many Marines being rotated in and out of the Caribbean and Central America for duty. The 2nd Marine Regiment kept a presence in Haiti, which the US had occupied since 1915. The 11th Marine Regiment and 5th Marine Regiment would conduct operations in Nicaragua. These conflicts coupled with the new directives from Springfield Armory saw Under receivers being replaced by Overs in large numbers and of high priority, the reason being the Under’s were considered unsafe for firing rifle grenades (though Rock Island made Under’s were considered still safe enough for rifle grenade use, though it does appear they were replaced in the case of infantrymen regardless). The practice of issuing active infantry Marines Over’s anytime possible would continue through the end of the M1903s service on the line.
Marines with their rifles in Nicaragua; Marine posing with his M1903 during duty in Haiti (photos: USMC)
The tropical environment was notoriously tough on barrels and stocks, and the archives are rife with Marines being docked pay to replace their unserviceable barrels with new ones. This was standard practice as rifles were issued to the individual Marine rather than to a unit, a practice which continued until very late in WWII. To combat the humid conditions in the tropics, some Marines decide to take matters into their own hands and apply a shellac to their rifle stocks. While this was assuredly successful at ebbing the swelling of the stocks in between periods of rain and heat, higher Marine command objected to the lack of uniformity in weapons that was being noticed when the Marines serving in the tropics were rotated to other units. These stocks were either stripped of their shellac by the individual Marines or sanded down at the Philadelphia QM Depot. However, the remnants of shellac can be observed on some stocks from time to time.
One of many order forms sent from the Quartermaster of the USMC Depot of Supplies in Philadelphia to Springfield Armory. After long campaigns in Nicaragua and Haiti, the Marines were sorely in need of barrels, stocks, and small parts (documents: NARA).
A Marine marksman with his M1903 (photo: NARA).
As the Banana Wars wound to a close, the years of 1931 and 1932 witnessed another major refitting similar in scale to the efforts of 1926-28. While this would conclude major item overhaul for the M1903 until later in the decade, other significant changes were in the works. The following decade would see the USMC M1903 transform into the most recognized version itself, as a multitude of major modifications lay ahead.
6th Marine in China during the interwar years (http://www.chinamarine.org).