WHY BULLPUPS?

© Anthony G Williams

This article is based on material in Assault Rifle: the Development of the Modern Military Rifle and its Ammunition with the addition of some further thoughts since this was published.

During the Second World War it became obvious that the bolt-action rifles used as standard by all armies except the USA were obsolescent. In fact, the German StG 44, which was in widespread service by the end of the war, emphasised the advantages of automatic as well as semi-automatic fire. The logic of this led several armies into the development of less powerful cartridges generating less recoil, to permit more controllable automatic fire.

In parallel with these developments, the British were attracted to the idea of a rifle which was made much shorter than standard (while retaining the same barrel length) by mounting the barrel and action far back in the stock, which would enable it to replace the sub-machine gun as well as the rifle: this is known as the "bullpup" layout. Bolt-action rifles of this type had been made as early as the 19^th century, and it seems that the name "bullpup" was applied to such guns in the USA in the 1920s, although the exact origin is obscure.

The British 7mm EM-2 rifle

The first serious attempt to apply the bullpup layout to a selective-fire military rifle was the British 7mm EM-2 of the late 1940s, which got as far as being formally adopted for the British Army in 1951 before this decision was reversed following a change of government. NATO's adoption of the too-powerful American 7.62x51 cartridge put this idea into abeyance for some time. During the 1970s it became clear that NATO was going to select a new, lower-powered cartridge to supplement the 7.62x51 rifle/MG round. It was accepted by most that the American 5.56x45 round would be chosen, as this had been in US service for over a decade already, so a number of new rifles were designed around this cartridge. Some of them were bullpups: the British produced what became the SA80 family (principally the L85 rifle and L86 light support weapon), Steyr of Austria produced the futuristic AUG and France the FAMAS. All of these were adopted for service, the Steyr achieving many export sales, but other designers stayed with the traditional layout.

Another generation of rifle designs began to emerge in the 1990s. Again, these showed a mixture of bullpup and traditional styles. Russia stayed with the traditional layout with the limited-production AN-94, as did Heckler & Koch with the successful G36 range. FN backed both horses, continuing the development of traditional guns, culminating in the USSOCOM SCAR rifles in 5.56mm and 7.62mm, but also developed the F2000 bullpup. Other bullpups also emerged, of which three significant models made it into production: Singapore's SAR-21, Israel's Tavor TAR-21 and the Chinese 5.8mm QBZ-95 (also available in 5.56mm as the QBZ-97).

Clearly, there is a divergence of views over the relative merits of the traditional and bullpup layouts. This article is an attempt to assess their pros and cons, and consider whether all options have yet been explored.

Pros and cons

The traditional layout has the magazine and action ahead of the trigger and pistol grip. This is really a hang-over from the days of bolt action rifles, in which the bolt handle needed to be close to the trigger for rapid operation; this inevitably meant that the magazine and action were in front. In bullpup rifles the action and magazine are located behind the trigger, within the buttstock, thereby producing a much shorter weapon for the same barrel length as the traditional type.

The photo below shows the M16 (top) and the L85: despite its shorter overall length, the L85 has a slightly longer barrel

The advantages in reducing the length vary according to the design, as shown below. Lengths are shown in centimetres first, with inches in brackets. The "carry length" is with the stock folded or telescoped (where possible). With either layout, the longer the barrel, the higher will be its percentage of the overall length (final column).

The significant reduction in overall length that the bullpup provides is obvious, but various objections are often raised against this type of layout.

The case against the bullpup

1. In most bullpups, fired cartridge cases can only be ejected to the right-hand side of the gun, which means that they cannot be fired left-handed as the cases would hit the firer's face (most can be adapted for left-handers, but that takes time). This means that users can't switch shoulders to fire round the corner of a building, for instance.

2. Magazine changes are also argued by some to be more awkward.

3. The necessarily straight-line stock means that the firer cannot sight along the top of the barrel, so if iron sights are used they have to stick up high above the barrel and the firer therefore has to expose more of his head 'above the parapet'.

4. Proponents of bayonet fighting will also point to the shorter length of the weapon, which means that you have to get closer to the enemy.

5. Those used to traditional rifles often claim that they feel better balanced with the weight forwards.

6. It is also frequently stated that bullpups have worse triggers than traditional guns, militating against accurate shooting.

7. Bullpups have the action by the firer's head, which some find uncomfortable, and short-barrelled versions have the muzzle quite close to the firer, which means that muzzle blast can be more of a problem.

8. Keeping the action well clear of the stock allows the stock to telescope in stages, in order to vary the length of pull to suit different users or different circumstances (e.g. wearing bulky body armour).

The case for the bullpup

There are of course counter-arguments:

1. The lack of ability to switch shoulders may in practice be very little used by ordinary soldiers as opposed to special forces. Most soldiers in combat have enough trouble hitting the target when firing from their usual shoulder, let alone from their 'wrong' side, so many armies train only in shooting from one shoulder. In any case, the FN F2000 overcomes this objection by being genuinely ambidextrous without any modifications or adjustments being required. This is achieved by adopting a forward ejection tube, which carries the spent cases to the front of the gun before they are expelled. Some have identified this as a potential source of problems, but user tests reported so far indicate that it is a robust and reliable system.

2. The magazine change is not necessarily more difficult (I have seen British soldiers changing magazines very quickly; there can only be a fraction of a second difference), and some users prefer the 'inboard' location as it can make it easier to change magazines when travelling in and shooting from a vehicle, or from behind cover.

3. Military rifles are increasingly being issued with optical sights, so the iron-sights objection is less important. In any case, military rifles of traditional layout also have high-mounted sights nowadays, because they generally have straight-line stocks, in which the top of the buttstock continues in a straight line from the barrel, instead of being angled downwards as in most older rifles.

4. Bayonets are now too irrelevant to modern combat situations for their length to matter.

5. Gun balance is, to a great extent, a matter of what you are used to. Bullpup users usually prefer the rearwards weight balance, arguing that it is easier to hold one-handed, or for extended periods, and makes the rifle quicker to change aim. What is undoubtedly true is that a bullpup is far more evenly balanced once an under-barrel grenade launcher, optical sights and other tactical kit (e.g. torches) start being added: a traditional rifle then becomes massively front-heavy.

6. While the triggers of some bullpups may not be good, most are entirely acceptable for their military (as opposed to target-shooting) purpose. The author has spent time on a range firing several modern military rifles – both bullpup and traditional – in quick succession, and never noticed any difference in the trigger actions.

7. Most significantly, bullpup proponents will point out that the increasing deployment of troops in cramped helicopters or armoured vehicles, together with the needs of urban combat, put a premium on compactness, as demonstrated by the fact that the US Army is gradually switching over from the M16 rifle to the M4 carbine.

Traditional rifles can only match a bullpup's short length by using stocks which can be folded alongside the barrel, or sometimes over the top of it. Folded-stock rifles are as short as bullpups for carrying purposes, but take a couple of seconds for the stock to be unfolded before use (essential to obtain any kind of accuracy), and of course in urban combat the stock needs to be in place, so the rifle is at full length. Furthermore, these folding stocks are commonly of the 'skeleton' type (i.e. they consist of an open framework) which may be less rigid and comfortable to shoot with than fixed stocks. Not all rifles are able to use folding stocks anyway because the action may extend into the stock (e.g. the M16 and M4). In such cases telescoping stocks may be used instead, but these do not deliver such a reduction in length as a folding stock, and cannot match the compactness of a bullpup.

The only other option to achieve a short length with a traditional layout is to reduce significantly the length of the barrel, to the detriment of ballistics and effectiveness, especially at longer ranges. This route has been followed by the US Army with the M4 carbine. Even so, with stock extended the M4 is 5.5cm (2 inches) longer than an L85 while having a barrel which is 15cm (6 inches) shorter.

Alternative bullpups?

Are there other types of bullpup layout which would help to get over the principal substantial objection to them: the problems of switching to firing left-handed (with the exception of the FN F2000 as noted above)? Two possible alternatives have occurred to the author (there may well be more).

One is to have the fired cases ejected straight upwards, in such a way that they strike the angled underside of a cheekpiece and are thereby deflected to one side, away from the firer. Switching sides would then be a matter of pivoting the cheekpiece over, which would take a couple of seconds. Putting a rubber pad on the underside of the cheekpiece would cushion the shock and encourage the cases to bounce well away from the gun.

Another solution could be to turn the action upside down so that ejection is downwards. The top-mounted magazine would be a drum rather than a box type, and could do double duty as a cheekpiece so that the firer could switch shoulders without needing to make any adjustments. This would incidentally provide a larger-capacity magazine without the usual disadvantage of excessive length under the gun, and the gravity-aided feed and ejection processes should be more reliable than a conventional gun's.

Whether the FN F2000 solution is adopted, or something different like those suggested above, it is clear that fully ambidextrous bullpups can be provided.

This leaves one practical disadvantage of the bullpup: the fact that the stock cannot be adjusted for length. While it could be argued that it isn't necessary because the vast majority of conventional rifles in service don't provide this anyway, it is clear that the US Army has decided that this is a worthwhile feature, so a bullpup should ideally offer this. It would of course be possible to design a bullpup with the action mounted slightly forward to provide room for a telescoping element in the butt, but this would increase the overall length of the gun, which should be avoided if at all possible.

An alternative approach would be to provide a pistol grip and trigger unit which can slide to some degree along the length of the gun, effectively altering the length of pull. The main problem that this would cause would be to ensure a reliable, good-quality connection with the sear. This would be straightforward if an electrical trigger system were adopted; while the thought of this would give many experienced soldiers palpitations, electrical systems are becoming increasingly essential to modern soldiers and will become even more so in the future. In any case, a sliding grip could be managed even with a conventional trigger. In a bullpup, a transfer bar is required to transmit the trigger movement to the sear in the stock. To design a bar with a series of holes, to provide alternative connecting points for the trigger mechanism, should not cause undue difficulties.

Conclusions

To sum up, there need no longer be any practical objections to the bullpup layout: those raised by supporters of traditional rifles can either be overcome, or on examination are not significant and often boil down to personal preference. Conversely, the major advantage of a saving of around 20cm (8 inches) in overall length for the same length barrel is very significant in modern conditions, as is the much superior weight balance when increasingly common accessories are added to the gun.

Further details plus illustrations of the guns mentioned in this article can be found on Maxim Popenker's site HERE

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