1. The troopers, by and large, carried the Colt Single Action Army in .45 caliber.
2. The issued pistol ammunition at that time was what we'd call the .45 Schoefield today: a case slightly shorter than the regular .45 Long Colt case. The Smith & Wesson Schofield revolver had a cylinder shorter than the Colt SAA.
To ensure that ammunition would work in either revolver, the U.S. military adopted the slightly shorter case. This was loaded with a 230 gr. lead bullet over 28 grs. of black powder: the standard military load of the day.
The civilian factory load of the day for the longer-cased .45 Long Colt had a 250 to 260 gr. bullet over 40 grs. of black powder. This civilian load would work in the Colt revolvers, but was too long to fully enter the S&W Schofield revolvers.
Undoubtedly, troopers bought the more powerful civilian load (250/40) from the fort’s sutler, or in town, for their Colts -- but this more powerful load was never issued.
3. Custer is known to have carried a variety of non-issue revolvers and rifles. Officers, especially those who were higher ranking, typically carried what they wanted -- especially if they were in the field, away from regulation hawks.
This practice was common again nearly 100 years later in Vietnam, where soldiers, sailors, marines and airmen carried the Browning Hi-Power 9mm, .357 Magnums, .38 Specials, .44 Magnum, .41 Magnum, .380 ACP and even the .22 rimfire for defense or special purposes.
4. The 1873 Springfield "trap door" rifle was actually a good rifle in its day. It had the advantage of a powerful camming system to extract fired or loaded cartridges, important when using a propellant that leaves 56 percent of itself behind as solids.
Then, the Springfield flung the empty case clear of the breech, leaving it empty for the next cartridge.
The Sharps, Remington and other single-shot rifles of the day had weaker extraction systems, and did not fling the empty or loaded cartridge clear. Their systems left the case 1/4 inch or so out of the chamber, to be picked out with your fingers and flung clear -- no small feat in a Dakota winter while wearing heavy gloves.
5. The Springfield 1873 rifle was quite accurate at very long range, out to 1,200 yards, in the hands of a good shooter -- when fed good ammo.
Alas, frontier forts typically received very little spare ammo for practice. If lucky, soldiers practiced twice a year. A major problem was ammunition quality.
Most military issue ammo was made on the East coast in government arsenals, thousands of miles from some of the remote Army posts out West. Most people today forget that, while the first transcontinental railroad was completed in 1869, it took decades to complete the track spurs that supplied the remote towns and forts.
Many places never received tracks, and freight was still shipped by wagons into the 1920s, (the last stagecoach robbery was in Jarbidge, Nevada in 1916!). Trucks still supply these small towns and cities.
During the long trip, ammunition was exposed to typically extreme changes in temperature and humidity. Bullet lubricant dried out. Priming compounds degraded. Though black powder is resistant to temperature extremes, it is badly degraded by even mild humidity.
The combination of very little practice, and ammunition of questionable quality, led to the i ncorrect belief that the Springfield 1873 was an inaccurate rifle. Blame the ammo and the shooter, but not the rifle itself. Even today, old Springfield 1873s with good bores, fed black powder ammunition made to fit, have exhibited good accuracy out to hundreds of yards.
6. The 1873 Springfield had a reputation for jamming, but this was actually attributable to its cartridge case and propellant. Troopers received ammunition assembled with cases made of nearly pure copper, a very soft metal. Black powder leaves behind 56% of itself as solids, converting 44 percent to gases to propel the bullet. Solid fouling clogs bores and chambers, combining with gun oil to create a black sludge on moving parts, retarding their movement.
Anyone who’s fired black powder can attest to its propensity to gum up the works, but the use of a moist bullet lubricant helps keep the fouling soft, for easier expelling by the bullet’s passage. Hard, dry lubricants won’t soften the fouling, and it tends to cake up in the chamber and bore.
7. The soft copper case expanded upon firing to the limits of the rifle’s chamber dimensions, and stayed almost that dimension. Under pressure, the soft copper case swelled over and around the fouling in the chamber, creating greater friction to remove it. The narrow, pivoting, hardened steel case extractor of the 1873 Springfield, bearing against the narrow copper rim of the case, tended to cut through the case rim rather than force the case out.
It was all due to metallurgy.
Copper cases swell to chamber dimensions when fired, and don’t retract much from that dimension.
Brass, composed of copper and tin, is much harder than pure copper. It also has a different and very important property: it will swell to the chamber dimension upon firing, then spring back nearer to its pre-fired dimension. This makes it looser in the chamber than the copper case. The 1873 Springfield’s narrow extractor can push against the brass case’s rim and push it out much easier, despite black powder fouling.
Brass is also more resistant to heat, and flowing under pressure, than copper.
A common remedy for removing a copper case stuck in the chamber of the 1873 Springfield was to pry it out by the rim, with the point of a knife. Cases with this tell-tale pry mark have been found at the Little Bighorn battlefield where Custer and his troopers died, but only a few.
According to Wikipedia, only 3.4% of the copper .45-70 cases recovered in a 1983 archaeological dig at the battlefield indicated they had been pried from chambers. The battle’s aftermath, and other complaints from the field, resulted in the Army changing the cases from copper to brass. However, I can find no reference as to when this change occurred. Some sources say immediately after the 1876 battle, others are imprecise.
When it comes to ammo, the military is reluctant to throw it away unless it’s explode-in-your-face dangerous. I suspect that the obsolete stocks of copper-cased ammo continued to be issued for target practice.
