Springfield Model 1888 Positive Cam Rifle
Serial Number 415509
Springfield Armory received field reports of instances when trapdoor Springfield breech blocks stuck shut or blew open when the rifle discharged while loading. The first examination of the problems was a result of Springfield Armory Post Order No. 17, dated April 19, 1883. Lieutenant Colonel A. R. Buffington set up a board of three officers and the Master Armorer to investigate. No recommendations were made at that time. On November 5, 1886, another board with Colonel Buffington was set up and the result was “Board did not feel justified in recommending such changes until the insecurity or other possible defects of the present mechanism become more evident”. The results of Colonel Buffington’s recommendation resulted in no locking cam systems being made at that time.
The issue of the breech block sticking in the closed position was attributed to the expansion of the breech parts when heated up during rapid fire. The locking cam breech was the result of the research into the problem. The theory was that by lifting the thumb piece the stuck cam would be moved left off of its seat freeing up the breech block so it could be opened. This feature also made the lock up of the breech stronger and capable of higher pressures. The system was used in the experimental trapdoors during the development of the smokeless .30 caliber round (.30/40) that would be used in the Krag Model 1892.
The issue of the rifle discharging while loading was attributed to either a firing pin stuck in the forward position or a broken firing pin with the tip stuck in the breach face. There was experimentation with different alloys to make the firing pins more durable and less prone to corrosion. An alloy of aluminum, copper and tin proved to be more durable and was approved for use in December of 1886. Springfield referred to the alloy as aluminum bronze.
These positive cam rifles were developed experimentally and about 100 were produced during the fiscal year of 1888. Most serial numbers are in the 415,000 range and are mostly sequential. Some knowledgeable sources think the serial numbers ranged from 415502 to 415615 consecutively with the exception of a few rejects during production. There are also a few known with close serial numbers that may be partially real, prototypes or proven fakes. This rifles receiver was produced between July and September of 1888. There are records stating that the rifles were sent to San Antonio Arsenal for testing. Some sources believe they were not tested while other sources believe they were and saw service in Texas, New Mexico and Arizona.
These rifles are virtually identical to the Model 1884 except for the receiver, breech screw, breech block, firing pin and screw, and cam latch components. The shaft of the cam latch has coarse thread which fit a like female thread cut into the breech block cap. The receivers are recessed on the right rear inside to accept the breech block caps shoulders that are larger than on standard caps. When viewing the breech block from the rear, lifting the thumb latch will move the cam to the left, freeing it from its positive locking position, and lowering the thumb latch will move the cam to the right to its locked position. The firing pin retaining screw hole is on the right side of the breech block instead of the bottom.
This rifles inspector’s cartouche of Samuel W. Porter, SWP over 1888, is in a box on the left wrist of the stock. The firing proof script P in a circle is rear of the trigger plate.
The stock has multiple nicks, dents and scratches. There is an insignificant drying crack rear of the lock plate. There are ten notches cut into the lower right rear of the butt forward of the butt plate. Above the notches is what may be a carved letter H. About 1 1/2” forward of the butt plate on the left side are the lightly scratched initials of W.T.R. or W.T.P. There is a chip missing at the bottom of the butt plate as well as forward of the cam latch at the receiver. The forend from the rear band forward has been replaced. The joint is under the rear band. The rod channel was obstructed from this repair and may explain why there was no cleaning rod with the rifle. I opened up the rod channel and installed a proper rod. During the cleaning process it was evident that this repair was made a long time ago. There is a steel reinforcement detected with a magnet. The stock was cleaned with lemon oil and coated with Renaissance wax.
The breech block of this rifle is marked U.S. over MODEL over 1888. The 100 rifles produced are the only ones that Springfield made having the 1888 date on the breech blocks. It does have a proper aluminum bronze firing pin. The pin is retained with a screw on the right side of the breech block behind the thumb piece of the cam latch. The firing pins retaining screw notch is cut on the bottom of the pin at an angle and is not perpendicular to the shaft because of the compound angle that the pin has as it passes through the breech block. The head of the pins retaining screw was broken off. I removed the screw remnant and made a new screw from an old trapdoor firing pin. The diameter of the pin is the same as the head of the screw and the steel can be re-hardened.
The barrel proof and inspection marks are on the left rear of the barrel. The V and P are 0.130” high. From the top of the V to the bottom of the eagle head is 0.560”. The head space is very generous at 0.082”. The bore has significant pitting mostly in the forward 10” to 12”. The barrel / receiver reference marks are in perfect alignment.
The lock plate is the fourth variation and was known to be used after about serial number 490,000. This places it outside the accepted serial number range but is believed to be original to the rifle. The eagles shield is 0.190” high. The eagle is 0.440” high with a wing span of 0.810”. The word SPRINGFIELD is 1.0” long and 0.11” high. The tumbler has three notches.
The sights on this rifle are of the last variant used on the trapdoors. The rear is a Buffington with 0.380” diameter knobs and the front is the pinned in replaceable with a rounded rear edge and thinned sides. The mounting screws of the Buffington have been replaced because the rear was missing and the front was badly damaged.
Published dimensions This rifle
O.A.L. 52” 52”
Stock length 48 3/4” 48 15/16”
Barrel length 32.6” 32 5/8”
Muzzle diameter 0.73” 0.730”
Front sight length 5/16” 11/32”
Sight from muzzle 1 1/4” 1 1/4”
Ramrod length 35 9/16” 35 9/16”
Head space Go = .070” No Go = .075” .082”
Various other markings
Rod stop PAT / AUG. 16 / 1870
Butt plate tang US
Butt plate back 8
Barrel bands U
Inside receiver belly of stock U
Trigger plate front R
Trigger bow inside 4, L
Trigger right side G
Sear spring O
Tumbler 6 or 9
Main spring hook end M
Top rear of barrel R
Bottom of barrel P, P, possible double struck tilde
Breech screw P, ///
Bottom of receiver H rear, A midpoint