Perception Meets Reality: The 2009 Enhanced Carbine Program

AAI 5.6x53mm SPIW with 3-shot sliding breech grenade launcher. (Author’s collection)

Last August, the Office of the Secretary of the Army announced a 2009 project to assess the current state of the art in small arms.  They are interested in providing a better service weapon to the soldier.  In addition to the improved reliability, durability, modularity and compatibility with accessories, the Army is seeking better accuracy and dispersion out to 600 meters, as compared with the current service weapon, the M4 Carbine.  Companies interested in competing were invited to a meeting in November to present their candidates to Army representatives.

This is not the first time the Army has sought weapons to meet these same or very similar requirements.  The perception of the SALVO program in 1951 was that a weapon firing multiple projectiles would increase hit probability.  Inaccuracies of the rifles in that era were understood to combine with further inaccuracy when a shooter entered the loop.  Combat stress made the system even more inaccurate.  SALVO investigators had numbers to back up their assertions.  In World War II, they determined that Infantrymen were inherently inaccurate with aiming errors accounting for the expenditure of 10,000 rounds for each hit on the battlefield.

Battlefield engagement ranges in those years were defined to be less than 300 yards three fourths of the time – much the same as it is today.  The weight of the ammunition and rifle was a concern so testing with lighter weight ammunition was conducted.  Their studies showed that tactically, a rifle/grenade launcher combination would offer significant advantages on the battlefield so obtaining such a system became a principal objective of the military.

They found that multiple fléchette rounds, used by some of the contenders, were quite inaccurate – only being useful at very close ranges.  Sabots used for the sub caliber fléchettes were unpopular with the evaluators, when fragments of the fiberglass were expelled into the air with each round fired.

During SALVO it was determined that high velocity projectiles smaller than 7.62mm, the size of the then current service round, could have equal or better lethality at a substantial savings in weight.  The use of fléchettes was not successful but got the concept rolling for a single conventional small bullet to be used in their place.  Another determination proved that a fully automatic rifle offered no advantage in increased hit probability.

Project SALVO was more about studying weapon, ammunition, and soldier performance than in developing a new service rifle.  Eugene Stoner’s 5.56mm M16 rifle offered some of the size, weight, and performance improvements determined in SALVO and was adopted just a few years after the SALVO project ended.

Research and development in small arms continued with the new Special Purpose Individual Weapon (SPIW) program in 1963.  The SPIW project objective was the development of a fieldable rifle using the other concepts developed on the SALVO program.  Candidate weapons came forth from H&R, AAI, Springfield Arsenal and Winchester; the latter three downselected and invited to Ft. Benning for trials.

The lightweight Winchester candidate was particularly innovative in that it was able to reduce recoil by allowing the action to reciprocate within the fiberglass stock as multiple rounds were fired.  The design turned out to be too complicated and couldn’t complete testing.

Dick Colby, the Chief Designer of Springfield Arsenal’s candidate, had the perception that his rifle would feed ammunition smoothly from a 60 round ammunition container.  Unfortunately, at 1,700 shots per minute, real-world vibration, dynamics, and other variables took over.  The Springfield SPIW could not be made to feed reliably, and was eliminated from the test.

The AAI entry gained the inside track, in spite of the fact that it was 10 pounds overweight.  The fin stabilized fléchettes launched in 3-round bursts with each trigger pull were impressive and accuracy was surprisingly good.  Bringing the weight down and solving the other technical problems proved too big a task for both the AAI and Springfield design teams.  Subsequently, program funding was lost and by 1974 the SPIW project was over.  Five years before SPIW ended, the AAI-developed M203 grenade launcher was adopted for use on the M16 rifle.  At last, a major objective of the SALVO/SPIW programs had been successfully achieved and fielded.

In 1986, the Army announced a new initiative to find a rifle to replace the M16A2.  The objective of the Advanced Combat Rifle (ACR) Program was to double the hit probability with two assumptions made: 1. The soldier would be stressed to further increase aiming errors.  2. These errors would be compensated with multiple projectiles launched with each squeeze of the trigger.

The conclusion from the study was that the aiming error introduced by the stressed soldier generated accuracy errors too large to be compensated by improved rifle technologies.  Not even multiple projectiles were found to be an acceptable solution.  The significance of this determination cannot be overstated.

With the ACR conclusion in mind, the use of airbursting munitions became an alternative to the single or multi-projectile firing rifle that was well worth consideration.  It would not only offer a better solution to the aiming error, but also have the potential to defeat targets in defilade.

On the Objective Individual Combat Weapon (OICW) Program that followed, the grenade launcher now became the primary weapon with a backup rifle underneath.  It was the perception of many, and in particular the competitors, that the backup rifle could be a small, pistol size caliber without detriment to the overall system effectiveness.  Reality set in when the U.S. Marine Corps insisted the caliber of the backup be 5.56mm NATO.  This introduced a substantial size and weight penalty to the detriment of the program.

On the new Enhanced Carbine program, potential competitors may today be envisioning their weapon systems functioning smoothly with rounds feeding properly and component parts rotating and sliding just as they should.  The real rifle world is a much uglier place where the Laws of Physics are greatly amplified by the whims of Mother Nature.  Military small arms live in a hostile environment that is full of mud, snow, rain, cold, sand, dust and extreme heat.  This is a world where it is often realized that nothing should ever be powered by gunpowder.

The reality is that small arms designers are engine designers where the engine is driven by a wretched substance called gunpowder.  Gunpowder is a substance that burns at high temperature and extreme pressure, emits toxic fumes and leaves behind a dirty, corrosive residue that defies removal.  Many say it burns with a grudge.  Small arms designers are, at the same time, rocket scientists who figure out how to propel missiles accurately from low-cost launch tubes without the benefit of onboard computers.

To all of the design challenges of the small arm, the soldier adds another variable that must be taken into consideration.  The small arm and the ammunition must be as light as possible, yet durable enough to stand the rigors of harsh environments and rough handling.  And yes, we have the technology and we have people who sent men to the moon, but Mission Control was not under mortar attack at the time.

Talented engineers, scientists, and technicians the world over have been trying to develop better and better small arms for centuries, but for all their efforts they are only ever able to nudge the technology forward.  Time to time great innovators as Browning, Stoner, and Kalashnikov come along, but in spite of their huge talents, are only able to give the technology a slightly bigger nudge.

On the Enhanced Carbine Program, it will be incumbent upon the Army to conduct testing that will prove beyond a doubt that the winner of the competition offers significant improvements in combat performance.  The new enhanced carbine has to run the real world gauntlet better than the carbine we already have.  Otherwise, it will sit in the gun rack while users beg for their old carbines to return.