The Definitive Military Service Calibre and Rifle For the 21st Century - Part 2

By Mike Staples

Over the last 100 years there have been many rifles, which in their day were considered by the countries using them and the men who carried them in war, as being the best rifle for the job. In the early years most were bolt action repeaters and. in the hands of well trained soldiers, were as good as any of today's rifles. What they may have lacked in rapid fire they made up in their simple action, reliability, accuracy and sturdy construction.

Today however, a soldieršs rifle is more than just a rifle, it is a "weapons platform." In the past a Section Strength force may have had one Light Machine Gun (LMG) and possibly a submachine gun or two. Todayšs Section would have an LMG and every soldier would be carrying a rifle that is capable of automatic fire and could even have a 40mm grenade launcher slung under the barrel.

For aiming they no longer rely on iron sights and most come standard with an optical sight of some sort. Most can exchange the basic sight with night vision optics, laser optics and other sundry sighting options.

Whilst optical sights are an advancement in terms of the accuracy achieved by the soldier, I wonder if it is a step in the right direction. They can be damaged, they must be kept clean, and any knock can move their zero point. (The same, of course, also applies to iron sights. -Ed.) The optical sight must also be securely fitted to the rifle.

How does a soldier, who may be fording rivers, trekking through impenetrable jungle, or sloshing through mud and the like keep the scope on his rifle from becoming caked in mud or waterlogged? How does a soldier aim his rifle at an enemy if he must first remove the mud that may be caked on the optics?

I realize that military optic sights are quite possibly stronger (in construction) than a civilian telescopic sight. However, they are still an optical sight. That being the case, like a good pair of glasses, they can be damaged. Unless the soldier has a backup, either iron sights or another optical sight, he is immediately at a disadvantage and would be a liability to his fellow soldiers.

Whilst the above may be an unfavorable opinion of optical sights, the gate is already open and the horse has bolted, so reverting to iron sights only would be a step backwards. Optical sights are here to stay and therefore must be made as strong as possible. They should incorporate some form of protection for the optics that will not detract from the soldier's ability to return fire, as quickly as possible, in a contact situation.

If the rumors that are circulating in Australiašs military forces, as well as those I hear from the States, are true, then there are moves afoot to change the Military or NATO calibre from the 5.56mm round to a larger calibre. To do this successfully a new rifle would be extremely desirable.

Research and development is a costly exercise regardless of what kind it is. I feel that a tried and proven rifle, which is capable of handling a bigger and more powerful calibre, albeit with some modifications, would be the best way to go, as dies and tooling should still be available for this rifle.

In my opinion, as a qualified Armaments Fitter, it was a mistake of huge proportions to abandon the 7.62 x 51mm round and the rifles that were chambered for it. And if a change had to be made, which I doubt, why was a glorified .22 calibre round, chosen? I believe that this move put the lives of many soldiers in danger, as it is imperative that the weapon they carry be able to immobilize or kill an enemy soldier with 1 round, at all ranges out to 500 yards.

The 5.56 round and the rifles that were designed for it should never have been used in warfare, as the round itself does not impart enough energy to the projectile to drop a living target much over 35 kilograms in weight (77 pounds). A man, who may weigh 75 kilograms (165 pounds) or more, is a far more difficult target to kill, especially at ranges beyond 200 yards (183 meters).

The 5.56mm round also has the propensity to deflect on hitting a hard object, i.e. a stone, so how can it be expected to punch a hole through sandbags or logs or other forms of cover, to disable or kill an enemy? True, the round has a very flat trajectory, however unless it is fired from an accurized rifle, this advantage is less important than it might otherwise appear.

As an indication, Australian Forces use the F88 Austeyr rifle/carbine, which the manufacturers suggest can achieve a 60mm group at 50 meters. I consider this to be very poor accuracy in a modern weapon. Ordinary hunting rifles in the same caliber regularly shoot groups of that size at 100 meters!

The primary positive aspect of the rifles chambered for this (5.56mm) round is they are capable of automatic fire. But if it takes 3 or 4 rounds to drop a man at 150 meters, unless it hits a bone with the first round, what good is it?

The definitive GPMR for the 21st century must be chambered for a round that is flatter shooting than the 7.62x51mm NATO round, hits harder than the 5.56mm NATO round, and must be capable of automatic fire.

Modern GPMRs are compact and except for the necessary metal parts, are either made from high impact plastics, carbon fibre composites, or other similar materials. They are very reminiscent of the rifles that many police forces use today. These semi-automatic or automatic weapons may be satisfactory for shooting bad guys in the close confines of inhabited city streets, where the populace must be protected from stray bullets, but they are not good enough for an all-around military rifle.

The rifle a soldier carries into a war zone has to be his best friend. It must, at the very least, be capable of killing or stopping his enemy with 1 round at a variety of ranges. He should not have to rely on 3 or 4 rounds hitting the enemy to stop him from shooting back.

If one of the reasons for the change to 5.56mm was that the soldier could carry more ammo, then this reasoning is flawed. The lighter caliber simply means that a soldier needs to use more than one round to take the enemy out.

The following are the attributes that I consider to be minimum requirements of the perfect GPMR.

  1. *Cost should not be a mitigating factor, unless it is way, way out of the ballpark. The front-line soldier must have the best rifle money can buy, as their lives and the lives of their fellow soldiers, depend on it. Its life span should be, at the very least, 75,000 rounds and any mechanical action, which may create stoppages, must be kept to an absolute minimum.
  2. *It should be comfortable to use and easy to operate; it must have both, single aimed shot capabilities via a self loading action and a fully automatic setting, for times of close contact with an enemy. Semi-auto fire should be from the closed bolt and closed chamber position. Automatic fire should be from the open bolt and open chamber position, to prevent cook-offs.
  3. *Its mechanical operation must be simple and loose minimal MV and energy, when reloading.
  4. *It should be gas operated, preferably with a short-stroke piston-style system, not a direct gas to bolt system. Recoil or blow back operation are not options.
  5. It should be short enough, to facilitate ease of use in heavy jungle type operations or the close confines of buildings in an urban operation.
  6. It should have an optic sight which is easily zeroed, is graduated for all ranges from 50 yards out to 400 yards and which has, at the very minimum, a 40mm exit optic with 4 power magnification. The optimum would be a 3 to 6 variable magnification with a 57mm exit optic (for more light gathering properties).
  7. As an optic sight can be damaged, the weapon must have an adjustable iron sight, which can be used with the optic sight attached to the rifle.
  8. The optic sight mount must also be able to accept all other sighting equipment, including night vision or low light optics and a sighting system which makes it possible for the rifle to be used with other attachments, i.e. grenade launchers and the like.
  9. It must be chambered for a suitable calibre that is conducive to automatic fire, has a flat trajectory and has knockdown power (kinetic energy) similar to or better than, the 7.62x 51 NATO round (see Part 1). Any section or platoon strength LMG should be chambered for the same cartridge.
  10. It must not weigh more than 8.5 pounds (3.86 kilograms), fully equipped with its standard sight and a 30 round mag. Making magazines from high impact plastic can save some weight. Making all parts that were previously wooden from a similar material to the magazines or even better, carbon fibre, can reduce weight further.
  11. It should be fully ambidextrous or available in both right hand and left-hand versions, as there are enough left handed, left eye dominant people in the military to warrant a left handed weapon.
  12. As rust is a problem, the rifle's metal parts, including the barrel, should be made from high quality stainless steel. Whilst the use of stainless steel may increase the unit cost, this will come down if it is adopted as a NATO GPMR. And the extended service life of the weapon will ultimately render it less expensive than an identical weapon manufactured from ferrous metal. External stainless steel parts, if used, can be dull coloured or camouflaged.
  13. *It must be accurate out to ranges of at least 400 yards (366 meters), with minimum groups of 6 inches (152mm) attainable at that range. Groupings, at the following ranges, should be considered minimum requirements, 25 yard or 22.85 meters .75"/19mm; 50 yards or 45.7 meters - 1.25"/32mm; 100 yards or 91.4 meters - 2"/50mm.
  14. *It should be able to be field striped for cleaning without the use of complex tools. There must be no small parts that are either hard to remove or easily lost when cleaning in the field.

Finally, once issued, the service rifle must remain with that person throughout his/her service life, or until it must be replaced or upgraded. The personal weapon of any soldier must be his or hers to keep from the time they start their training. Only in this manner can they become familiar with it, confident of it, and an expert in its use. Once these things have been achieved, it will become their friend and they will treat it with the respect it deserves.

A rifle which has many of the above attributes (*) already exists and is a tried and proven GPMR and is in fact, considered to be the best battlefield rifle ever made.

The rifle in question, is the Australian, Canadian and British L1A1 7.62x51mm Self-Loading Rifle (SLR), which was made under license from Fabrique Nationale. This rifle was made under license by a multitude of countries and has been used by as many as 90 since its inception in the 1950s. Some countries still use it to this day, and a great many have been produced over the years.

Research and development is a costly expense when designing and manufacturing any mechanical product and a rifle, in most cases, even more so. That being the case and as tooling and dies would still exist for the L1A1, any adaptations or alterations to take in those criteria not marked with an asterisk (*) would be easily achieved.

The most important alterations would be the engineering to make it fully automatic (safely), the reduction in length and weight, availability of a left hand version, and chambering the rifle for the round as suggested in Part 1 (.270 or 6.85mm).

As an Armament Fitter I have worked on a lot of these rifles over my years in the Army and have rebuilt quite a few. One in particular, whilst I was in Vietnam, was very badly mangled and whilst my boss suggested the "gas axe" solution, I felt that it could be rebuilt, albeit with some radical alterations.

The first problem was the barrel, as it was bent about 25 degrees out of true. By the time I achieved a straight barrel, it had been reduced by around 7 inches and finished approximately .75 of an inch in front of the gas plug. The rest of the repairs involved the body, the gas cylinder, the return spring and tube, the fore end and butt and the front sight.

By the time it was finished, the rifle was some 8.5 inches shorter than standard, with the shortened barrel accounting for much of that reduction. I converted it to fire fully automatic, and it was when I was test firing it that I discovered why it had never been made as an automatic rifle, although we did have an automatic heavy barrel version.

I had put two 30 round mags through it and clipped in a third, only to have it run away on me as soon as I cocked the weapon. The heat generated in the breach was enough to cook-off the rounds before the bolt was fully locked. Since both sears were irrelevant in these circumstances, the rifle continued to fire until the magazine was empty. Luckily this only took about 3 seconds, but it highlighted a very serious problem and one that nagged me for many years.

I also test fired this rifle at 200 meters and found that it was a little more accurate than a standard SLR. However, as I did not have access to a range out to 500 meters, I cannot suggest that it would be so at those ranges. That said and with the advancements in ballistic technology over the last 30 years or so, I feel the original 4 grove barrel with a 1 in 12" twist could be upgraded to a 5 or 7 grove barrel with a 1 in 10" twist by using micro grove technology. These changes would stabilize the smaller length and diameter projectile of the .270 much better.

About a month after this occurred we were modifying our Browning .30 caliber machine guns to fire from the open bolt, open chamber position. I considered doing the same to this particular SLR. However, whilst the idea would solve the problem of cook-offs and make it possible for every Australian SLR to be used fully automatic, the actual mechanical modification was a little harder to envisage.

Over the years many ideas were dismissed and it was not until 16 years after my discharge, and at about the time the SLR was phased out of the Australian Forces, that the penny finally dropped. I had considered this idea whilst still in Vietnam, but had abandoned it as being too simple a solution to the problem. If I had gone with my intuition then, Australian troops might have had access to an automatic rifle in Vietnam and the SLR might still be the Australian GPMR of choice.

As is often the case, the simplest solution to a mechanical problem is usually the best. As the rumors have suggest a change of calibre may be imminent, I have decided to push this conversion of the "old girl" and make it possible for her to be resurrected.

I will not divulge how to achieve these critical modifications, which also includes the barrel, in this article, as they are my intellectual property. However, I would invite those people who are in a position to have some influence on the decision to make the NATO calibre bigger and the companies who would be competing for the contracts to build a new rifle to suit that calibre, to make contact with me via these pages.

Suffice to say, they will save the companies involved millions of dollars in R&D, but more importantly will see what was, arguably, the best battlefield rifle ever made back in the hands of competent soldiers.

No longer will their lives be placed in jeopardy by an ineffectual rifle and cartridge. Instead they will have a rifle which will, with a few rounds, destroy most of the cover their enemy uses in an ambush situation, and which can, with one well aimed shot, take out an enemy at 400 to 500 yards.

The other upside of this is that those countries which still use the SLR, would be walk up customers to have their rifles modified to fire safely on automatic. At the very least they could have them modified to suit the new calibre and round.

We have a saying here in Australia, "If it ain't broke, don't try and fix it." This was the case with the L1A1 SLR, as it was certainly not broken. So why get rid of it for something which was, in my opinion, not a worthy substitute or successor. True, the old girl may have needed some upgrading and modernization, but the basic mechanical foundation of the rifle itself would have gone unchanged.

Whilst the opinions voiced in this article are mine alone, I have found that they are shared by many current and ex-serving members of Australiašs Defence Forces, who have used both weapons. Also many U.S. veteran soldiers, especially those who have used both the M16 and the M-14 or M1 Garand.

Our experiences in war are invaluable. Maybe the people who instigated the changes to make the NATO standard calibre the 5.56mm round should have talked to us first.

History between our two countries clearly establishes rifle calibres of around .300 inches are best in a war zone, as does many rifles and calibres from opposing forces. The exception to this, even though it is a .303 calibre round, is the 7.62 x 39mm, as used in the various copies and variants of the AK 47. Whilst the AK 47 and Chinese SKS are capable of automatic fire, their useful range is even less than that of rifles chambered for the 5.56mm.

On August 18th 1966, at the Battle of Long Tan, the outcome may have been decidedly different had our forces been armed with the M16 Armalite. The long range and hard-hitting power of the SLR and its 7.62x51mm round made all the difference in that rubber plantation. We were able to engage the enemy at longer ranges, and rubber trees do not offer much protection against a swarm of 168 grain 7.62 projectiles travelling at a MV of 2650 FPS.

108 men from D Company 6 Battalion RAR, assisted by artillery fire from Nui Dat and a troop of APCs from A Sqdn 3 Cav Regiment, held an overwhelming force of VC and NVA forces, estimated at a strength of close to 2,500 men, at bay for 24 hours. We lost 18 good men, with 21 wounded, but the estimated enemy KIA, was in excess of 245, with wounded unknown. Three enemy soldiers were captured.

Much later VC records captured by US forces indicate that the VC & NVA force at Long Tan lost 500 KIA and 750 WIA. This was an overwhelming victory. Documents captured during the war and only released a short while ago suggest that the VC & NVA did everything possible to avoid contact with Australian Soldiers after Long Tan. (MAIN SOURCE:

Many Australian soldiers owe their lives to this unique and reliable rifle, and those who serve today deserve a personal weapon that is at least as good as the L1A1 SLR. The Austeyr and other weapons, which are chambered for the 5.56mm round, do not even come close.

Back to Naval & Military History

Copyright 2005, 2016 by Mike Staples and/or All rights reserved.