Solomon Birch is a logistics officer who is currently posted to CIOG and in the process of transferring to the reserves. The author would like to thank Chris Masters, Darren Christopher, Mark Richards, LTCOL Mathew Brookes, LTCOL Cameron Fraser, and Major Yong Yi, as well as the large number of unnamed individuals, for their assistance in gathering information for these articles. Finally, if anyone knows the location of a surviving F88-S, could they please raise it to the attention of the Australian Army History Unit, as no examples are currently thought to exist.


These articles originally started as an academic paper intended for the Australian Army Journal that documented, in some detail, the development of the F88, M4 and M4-like rifles from 1988 onwards. Its purpose was to compare the rifles and the detailed history, but while interesting if you’re the kind of person who likes to watch Ian McCollum from Forgotten Weapons, it was really pitched at the wrong audience.

The purpose of this series of five articles is to provide a succinct and accessible resource for members of the Australian Army engaging in conversation about the relative merits of the EF88 and M4 in order to improve the quality of discussion on small arms. The method of this article is to outline the context of both rifles’ design development, to dispel common misconceptions in the area and to try to understand the social phenomenon of some soldier’s preference for the M4 FOW over the F88 FOW. In doing this, several documents have been declassified or collated and made publicly available so as to help to improve the factual basis of discussion on the topic. In short, all of the weapons in discussion are very good and have a variety of subtle strengths and weaknesses that tend to be overstated in general discussion.

In researching and writing these articles the author came to the view that the EF88 is a substantially better rifle than the M4A1 in most common-use cases for a service rifle because it is generally more accurate, more reliable, more lethal and easier to maintain, but that the M4A1 is better in some niche-use cases because it’s lighter, more ergonomic, handles better in most ways, and is more commonly used world-wide, resulting in a better parts aftermarket for it.

This series of articles is being published in five parts:

  1. Today: Context and the Ancient History – The M16 and the Steyr AUG
  2. Tue, 16 Jul: The Middle History – The M4A1 and the F88SA1/2
  3. Wed, 17 Jul: The Late History: EF88 and M4 Spinoffs
  4. Thu, 18 Jul: The Human Factor Part 1: The reason these articles exist: Why there is a group of regular soldiers who like the M4 and hate the F88
  5. Fri, 19 Jul: The Human Factor Part 2: SF Cast A Long Shadow

Context and ancient history

Experimental M16 in Vietnam

The M16 and the Steyr AUG

The M16 was based on the Armalite Rifle Model 15 (AR15). The AR15 was based on the AR10 which was designed from 1953 to 1955. The AR15 was designed from 1957 to 1959 and was first adopted into US military service in 1963. It was 39.5 inches long, had a 20 inch barrel and weighed 3.1kg unloaded. It was noteworthy because of its use of 'space age'” materials (primarily aluminium, but some plastic), and for the introduction of an intermediate calibre cartridge, the 5.56x45mm M193, which achieved acceptable lethality because of its very high velocity[i]. It cycles its bolt by sending gas ported from the barrel through a tube all the way back to the bolt carrier which the gas directly pushes (sometimes this is called a 'direct impingement system'). There were serious problems with its reliability early in its service life in Vietnam, mostly because the type of propellant used for the ammunition differed from that for which it was designed. However, the reliability problems were largely resolved with design changes and improved parts[ii].

Operating mechanism comparison

The M16 and M16A1 were first introduced in to the US military in 1963. In 1983 the M16A2 was introduced with a new barrel that would let it use heavier, armour piercing ammunition and finally, in 1996, the M16A3 and M16A4 were introduced that had MIL-STD 1913 'Picatinny' rails so that standardised optics could be mounted to the system. Each iteration also had a number of other, less pronounced, changes that are not mentioned. Each subsequent version weighed more than its predecessors, but all kept the 20 inch barrel and were about the same overall length.

The Steyr AUG started being designed in about 1973 and was adopted by the Austrian military in 1977. It was 31.1 inches long, had a 20 inch barrel and weighed 3.6kg unloaded. It had a number of noteworthy features, but is mostly known for placing the operating parts of the weapon behind the trigger (making it a 'bullpup'), including a lot of plastic in the design and including an integral optic, which were all almost unheard of for a service rifle at the time. It cycles its action by sending gas ported from the barrel into a piston that travels a short distance and strikes a rod protruding from the bolt carrier, pushing it to cycle the action (called a 'short stroke gas piston system'). It underwent a number of minor modifications as other militaries adopted it, for example the inclusion of the single shot lockout for the Irish Army procurement.

From about 1982 the Australian Army wanted to replace its L1A1 Self-Loading Rifles with something newer and chambered for 5.56x45mm[iii]. It conducted a Small Arms Replacement Program (SARP) where the final trials in 1985 were between the Steyr AUG and the M16A2. The Steyr AUG conclusively trounced the M16A2 in almost every area[iv]. The M16 suffered more stoppages, its parts broke more frequently, its barrels did not meet the barrel life expectations, it was much less accurate, much more difficult to maintain and it failed the majority of adverse conditions tests. The SARP Evaluation Report (Volume One) (Volume Two) (Volume Three) contains the following General Comment Trial Staff: 'Without, exception, including the soldier firers, all preferred the Steyr in terms of shooting, performance, cleaning, maintenance and handling', and the following conclusion 'From the results of the Engineering Evaluation, EDE has no hesitation in stating the Steyr is the significantly better weapon of the [individual weapon] contenders, in terms of satisfying the engineering aspects of [the Army requirement], and is considered suitable for introduction into service without any modifications.' There are rumours still in circulation that the AUG was selected because Colt would not license production of the M16A2 in Australia – if this is true[v] it doesn’t seem to be the main reason the AUG was selected and Colt licensed manufacture in other countries in the period (for example, Diemaco Canada). In 1988 the Australian Defence Force adopted the Steyr AUG as the F88.

F88 and the weapons it replaced

Much like the M16 in early US service, the F88 encountered some initial problems that were ultimately corrected by improvements to quality control and production methods at Lithgow. When the design was introduced, certain elements of the design were amended, for example a change to the materials and design of the main operating spring, and while the individual changes each appeared to be within tolerance, some tolerance stacks occurred which reduced the reliability of the weapon to levels below that seen in the trial[vi]. In all cases, the problems were resolved with modifications to the parts and improved quality control. However, initial reputational damage had already been inflicted on the weapon in some parts of the Army (particularly special forces, who had received some of the first batches of F88). This reputational damage was exacerbated by use of the weapon in situations that fell outside the user requirements that Army had stipulated and for which the weapon was never intended and never tested, for example for submarine insertion and over the beach operations in which the firearm would experience hydrostatic lock (a limitation common to nearly all automatic firearms to some degree when fired with water in the working parts, and reportedly why the weapon preferred by many special operators for such cases is a double action revolver)[vii][viii]. Speaking to early users of the F88 in the Army, it seems to have been substantially preferred over the L1A1 SLR and M16 that it replaced due to its light weight, short length, better reliability and easier handling characteristics, but there were some initial misgivings due to the unconventional design and materials combined with the initial quality control problems.