Small arms innovation has been the determination of what an infantry-based army is capable of for centuries. In ancient times, soldiers with iron swords and spearpoints made cheese-graters out of Bronze-Age armor. Troops carrying muskets made heavy steel armor, the standard of warfare for generations, obsolete. Later, soldiers armed with repeaters and revolvers were far more effective in combat against enemies armed with single-shot muzzleloaders.
On and on the progression marches, through the trenches of WWI and the European and Pacific theaters of WWII, all the way to modern times. The rifle is the modern sword and shield, the tool of a soldier on the battlefield so intimate that many veterans still remember the serial number from the gun they were first issued.
Here we take a quick tour through the long-guns that have served U.S. armed forces since the nation began, from the first rifles that earned Americans the reputation of expert marksmen to the modern battlefield implements of today.
The original American small arm was the muzzleloading long rifle, also known as the Pennsylvania Rifle or the Kentucky Rifle, which helped the fledgling nation win its independence from Britain. The musket known as the Brown Bess was also quite common in the colonies at the time, which was the standard British long gun from 1722 until 1838—but unlike the American long guns, the Brown Bess was a smoothbore flintlock with no rifling.
The long guns were mostly modified small frame rifles that were originally designed in Europe and could be accurate out to about 270 yards, but fired a relatively small caliber projectile, usually somewhere between .32 and .45 caliber, from very long barrels.
A piece of flint was grasped in the vice-like jaws held in place by a screw wrapped in a felt pad to keep it from cracking. When the trigger is pulled, the flint strikes the frizzen which generates a spark that ignites powder in the flash pan, which in turn ignites the main charge in the barrel and fires the weapon.
Each time the weapon was loaded, powder had to be poured into the flash pan as well as the barrel before the rifle could be cocked and fired—not exactly easy to do under battle stress and/or in wet conditions. Even so, these weapons dominated the battlefield for about 100 years.
Flintlocks were eventually succeeded by muzzleloading caplock rifles. To ignite the main charge, a percussion cap, which is basically just a big primer, was struck by the hammer and, in turn, ignited the main charge in the barrel. It replaced the entire flint assembly, frizzen, and flash pan with a simple hammer and the step of placing a cap on the nipple cone, creating a significant advantage for battlefield troops.
The system was actually patented way back in 1807 by Rev. Alexander John Forsyth, because he got sick of birds getting spooked by the smoke from the flash pan before his shot was fired, though he never got beyond that point. It wasn’t until Forsyth’s patents expired that the system was actually developed. Many older flintlock weapons were converted to caplocks once their use became common.
An example from this era is the Enfield Pattern 1853 rifle-musket, which was a .577 caliber Minié-type muzzleloader and was used by the British Empire from 1853 to 1867. On the American side of the pond, the Springfield Rifle Musket or the Springfield Model 1861, a .58-caliber Minié ball rifled muzzleloader, became a common arm during the Civil War. It was capable of hitting a man-sized target at distances as great as 500 yards. Along with the revised 1863 model, it was the last muzzleloader adopted by the U.S. Army.
By the end of the Civil War, about 1.5 million Springfield rifle muskets had been produced.
Next up is 1873 Trapdoor Springfield, representative of the beginning of the age of the metallic cartridge and the breech-loading rifle, forever making muzzleloaders and other actions curiosities for hunters and collectors.
At the tail end of the Civil War, cartridge guns like the first lever rifles and the Spencer rifle began appearing on the battlefield. But that was a time of great transition for firearms, and the military was slow to catch up. In the 1870s the military officially adopted the Trapdoor Springfield in full length and carbine versions. It was a single-shot rifle that took a .45-70 rimfire cartridge that was originally made of copper—which expanded too much in the breech when the round was fired, and grew a green film of oxidation when carried in leather shell holders that often jammed the Springfield.
This was a serious problem for the carbine version, which had no ramrod to clear it. Brass eventually replaced copper and became the new standard for all cartridges.
The Model 1873 was replaced by the Springfield Model 1892 bolt-action rifle, which had an action based on the Norewegian Krag-Jorgensen action. It was the first rifle in .30 caliber, and the first using smokeless powder in a rimmed centerfire cartridge, bringing us closer to the modern age of firearms. It had an unusual feeding system and wasn’t around for long, but it represented two huge advancements for U.S. military arms.
It held more than one round and fired a pointed (spitzer shaped) cartridge increasing it’s range, accuracy, and velocity over the round or flat-nosed bullets which were required for use with a lever-action rifle.
After the Spanish American War in 1898 the U.S. copied the design of the Mauser action to create the Springfield M1903 bolt-action rifle.
It had an internal magazine, with some variants holding up to 25 rounds, and could be quickly loaded with stripper clips.
The bolt-action rifle most commonly held five rounds and was originally chambered in .30-03, but was soon manufactured in the new .30-06 cartridge.
The M1903 was officially adopted as the U.S. military’s service rifle in 1903 and was our go-to rifle in World War I. It saw continued use in WWII, even as it was being phased out and was officially replaced by the semi-auto M1 Garand beginning in 1937.
It was also used as a sniper rifle in WWII, in the Korean War, and even in the early stages of the Vietnam War.
Now, it’s a classic bolt-gun that’s still very effective and is popular with civilians, collectors, and as a military drill rifle.
During World War II, the semi-automatic M1 Garand began to replace the Springfield ’03, representing a permanent shift for the U.S. military toward semi-auto gas-operated rifles. In fact, it was the first semi-auto rifle every issued by any military.
As the ’03 was the definitive American rifle during WWI, the Garand was such for the Second World War, seeing heavy action and gaining a reputation as a rugged, and reliable rifle, even if it was a little heavy.
The only wide criticism of the rifle was the fact that it had an internal magazine that was loaded by an en-bloc, a metal clip that holds 8 rounds, instead of a detachable box magazine. The clip ejected with the last round, making a distinctive ping sound, which some speculated the enemy could hear and use as an indicator of when to attack, though this is unlikely. Another down-side the Garand shared with almost every rifle of the time was that its wood stock tended swell and warp in humid and wet climates, affecting the rifle’s accuracy.
The Garand was fielded by U.S. troops through the Korean war, until the M14 came along.
While the M1 Garand was a fine, reliable, and powerful, it was large, heavy, and cumbersome for many combat roles, with a length of 43.5 inches and a weight of as much as 11.6 pounds. The M1 Carbine filled the roles that a Garand could not, especially for troops serving in specialized roles such as paratroopers and tank crewmembers.
The original design for the M1 Carbine, which won a military competition in 1941, was designed by Jonathan “Ed” Browning, brother of the more famous John Moses Browning for Winchester. After Browning’s death, Winchester hired David Marshall Williams to complete the design. After much testing and refinement, the M1 Carbine was approved on Oct. 22, 1941.
The M1 Carbine weighed 5.8 pounds fully loaded with a sling with a length of just 35.6 inches and an 18-inch barrel. The gun feeds from a detachable box magazine of varying capacities and is chambered for the .30 Carbine round, which is a rimless version of the old .32 Winchester Self-Loading cartridge, introduced with the Winchester Model 1905 rifle, though with modern propellant, the .30 Carbine was about 27 percent more powerful.
At 100 yards, the M1 Carbine could delivers groups between 3 and 5 inches with a maximum range of 300 yards, though bullet drop is significant beyond 200 yards. A paratrooper version of the carbine was later issued during the war with a folding wire stock that made the gun even more compact for jumps. It could be fired with the stock folded or extended and quickly deployed once troopers hit the ground.
The M2 Carbine was also introduced during the war in 1944 with a selective fire switch, allowing it to run in full-auto at 750 rounds per minute.
Though it was never intended to serve as a primary weapon for combat infantrymen, the M1 and M2 Carbines were superior to the .45 ACP 1911 pistol and soldiers could carry more .30 caliber ammo than they could .30-06. it was eventually widely issued and used, though there were regular reports of poor stopping power from the .30 Carbine round—however its use of non-corrosive primers was a godsend to troops serving in the humid Pacific jungles.
The M1 and M2 received small updates through Korea and Vietnam, and semi-auto versions became quite popular on the civilian market for many years.
The M14 was intended to replace the M1 Garand and was issued from 1959 until 1964. It was, for the most part, an M1 Garand with a detachable box magazine and a tweaked gas system. It was a big advantage over the M1 in some respects, but it was still a very heavy rifle, though it fired the .308 Win, or 7.62 x 51mm NATO, a smaller round than the .30-06. It fired in full-auto, but it was not very accurate in that mode. It’s still regarded as a very accurate in semi-auto fire.
While it was quickly replaced during the Vietnam War by the M16 and was never really viable as a widely-issued infantry arm, the M14 didn’t die and became useful as a special-purpose long-range rifle. In the 1970s, the Army converted several thousand M14s to M21 sniper rifles, which remained the standard issue semi-auto long-range rifle until the adoption of the M24 SWS in 1988.
In the mid-1990s, the U.S. Marine Corps chose a new gun to serve as a Designated Marksman Rifle and gave the old M14 a new life. They chose M14s modified by the Precision Weapons Shop in Marine Corps Base Quantico designated the DMR. It was intended to be used by security teams and Marine Scout Snipers in the cases where a semi-auto rifle would be more appropriate than a bolt gun.
The USMC still uses the M14 in shooting competitions, and various configurations are still used in specialty roles by various branches.
The M14 was replaced early in the Vietnam War by the much lighter and smaller M16 rifle, which also boasted a synthetic stock and forend that would not swell and warp in the jungle humidity.
The first M16 issued to troops was based on Eugene Stoner’s AR-15 designed by Armalite, and included modern materials for the time like aluminum and polymers. Instead of the M14’s .308 Win. or the .30-06 before it, the M16 opted for smaller, faster projectiles and a greater ammo capacity instead of longer-range, harder hitting battle rifle calibers. Consequently, the new rifle was chambered for the small and speedy 5.56×45 round.
The original M16 had a lot of problems, mostly due to the ammo issued for it being loaded with the wrong powder, and the barrel not being chrome-lined as the prototypes were, leading to a lot of jams and hatred for the new “plastic” rifle, not to mention resulting U.S. casualties.
It didn’t help that the M16 was billed as a self-cleaning rifle and wasn’t even issued with a cleaning kit at first. It was quickly realized that a direct impingement rifle, which channels gas from the bore directly into the action to move the bolt, is far from self-cleaning. The M16A1 fixed a lot of these problems along with changes to the rifle’s magazine construction. It added a forward assist, which was designed to help seat a round in the chamber when reloading, a bras deflector, chrome lined chambered and barrel, and a new flash hider that wouldn’t catch on straps and foliage. Most remaining design flaws were solved with the introduction of the M16A2.
The most current version of the rifle, the M16A4, ditched the integrated carry handle for a full-top rail and removable carry handle with additional Picatinny rail sections, so a variety of modern optics and accessories could be more easily integrated, though it retains the M16’s integrated front sight, which is part of the gas block.
Variants of the M16 are still in service today, though it has been replaced by the shorter M4 Carbine for many applications.
The M4 is the carbine version of the M16, with a collapsible stock and shorter length (usually a 14-inch barrel), but still chambered for the 5.56.
It’s an evolution of the Colt Automatic Rifle-15 Military Weapons System, better known as the CAR-15, which was made by Colt in the late 1960s and early 1970s and was used by some units in Vietnam. Afterward, it was issued as the Colt Commando for applications that required more mobility and compactness, but better range and a harder-hitting round than the pistol-caliber MP5 submachine gun or the aging M3 “Grease Gun”.
The M4 carbine was developed from a variety of shortened M16A1-style carbines. The XM4 (Colt Model 727) started its military trials in the mid-1980s with a 14.5-inch barrel. It was officially adopted in 1994 as a replacement for the M3 submachine gun as well as for the Beretta M9 pistol and the M16A2 for some troops.
It has since seen extensive use in the Afghanistan and Iraq theaters, where it’s compact size and versatility has proven advantageous in the often confined, building-to-building fighting U.S. troops most often engage in. The smaller M4 is also easier for vehicle-mounted troops to handle.
Currently, the Marine Corps and U.S. Army are both in the process of phasing out the M16 and bringing in the M4 as their standard service weapon.
The M4 has three-round-burst and semi-auto firing modes, while the M4A1 carbine has a fully automatic firing mode instead of the burst. Both have a full Picatinny top rail for mounting optics and accessories.