Sometimes we tend to put too much emphasis on the rifle. For long range combat the mortar and the machine gun are more effective. At close range the grenade is often more effective and tactically more prudent. The grenade produces no muzzle flash and can be thrown from concealed positions. Its noise can be mistaken for booby trap, artillery or mortar fire. On the other hand, modern combat involves many situations where the enemy must be eliminated with the minimum risk of collateral damage and for this the rifle is perfect.
We live in a world of ironies. The British army desperately needs a new assault rifle but intends to continue fielding the disastrous SA-80 until 2020. The US military has large numbers of the perfectly acceptable M16 family of weapons yet there are factions that are campaigning for the adoption of the XM8, an Americanized Heckler and Koch G36. The G36 seems to be a quite capable weapon but the bottom line is that it doesn't represent a significant advance over the M16 to be worth the expense. Some wild and sometimes stupid claims have been made about the XM8. It's been claimed that it is modular and the M16 FOW is not, which is blatantly false, as can be seen here. It is claimed that it will be lighter than the M16. This seems to be arrived at by comparing a 20 barreled M16 with a 12.5 barreled XM8 prototype. The 16 M4 is a shade lighter than the published XM8. It has been claimed that a XM8 with a 12.5 barrel has a muzzle velocity equal or greater than a AR-15 type weapon with a 16-20 barrel, despite using the same ammunition. The very idea of issuing 5.56mm standard weapons with 12.5 barrels is in itself nonsense, since this would severely compromise terminal and exterior ballistics.
Below is a rewriting of one of the older Scrapboard articles. Unlike the US at the moment many nations do need a new model of rifle. Some references are made to the 6.8mm SPC round. See this page for the reasons I no longer think this is the most prudent choice of new round.
Any new model of rifle should have the following features:-
Overall length of the rifle should not exceed 36. This is to make the rifle more manageable in confined spaces such a building or vehicle interiors. The requirement for a barrel of sufficient length to ensure good penetration and ballistics (16-18) may result in a weapon that is a shade longer but this can be offset somewhat by provision of an effective and compact folding stock.
The weapon should be of conventional configuration unless it can be fired from either shoulder without modification. As is described on the SA-80 page a combat bullpup rifle is a tactical liability unless it can be fired from either shoulder without the need for modification.
A good set of good iron sights should be fitted in addition to any optics. If the rifle can be disassembled into two parts, both sights should be on the same half. A good model of rear sight would be the disc aperture sight used on the Canadian C1 rifle. Settings would be Close, Battle, 400m, 500m, and 600m. Combat shooting with a rifle at targets further than 600m away using iron sights is probably overly optimistic. Battle setting would be for the optimum point blank range for an 11 diameter target area. For the M855 5.56mm round this is a 33/326 yd zero to fire out to 381 yds. For the proposed 6.5mm MPC this would be around 26/263 yds for a 309yd mean point blank range (MPBR). Close setting would be for shorter-range precision fire and would give a mid-range trajectory of no greater than +1.5. For the M855 that would be a 54/215 yd zero, which gives a MPBR for a 3 target of 246 yds. For the 6.5mm MPC a 43/171 yd zero gives 197 yds. The front sight blade would be proportioned to assist the shooter in range estimation. Apparent width would match that of a man's shoulders at 300m (a feature of the current M16). Blade would also be marked to correspond to a man's apparent height at 300m.
Any Optic scope used should include a low-power or x1 setting for close range combat.
If of a conventional configuration a folding stock should be provided. Possibly the best choice would be a stock similar to that of the original AR-18 rifles but with lightening holes and a telescopic section that can be adjusted to suit the firer's proportions or allow for extra clothing being worn. A side-folding stock should not obscure the weapon's controls. Some models such as the Galil prevent access to the cocking handle and/or selector. The stock should be robust enough to be used as a weapon in close combat or used for such common tasks as breaking down doors.
The gas system would most likely be of conventional configuration ie, having a gas piston rather than direct gas action. An adjustable gas regulator such as the 13 position model fitted to the FN FAL would be a prudent addition. However, an Exhaust to Atmosphere regulator does have some drawbacks if Rifle-launched grenades are used. It may be simpler to give the rifle an adjustable closed gas system like the Dragunov SVD or Browning BAR M1918. The SVD has a two position regulator (for normal and adverse conditions) that is altered with a cartridge case while the BAR needed a combination tool but had three positions (Normal, Dirty and Very Dirty?).
Controls should be ambidextrous and their operation and location resemble those of current weapons such as the M16 where possible.
A two-round burst mechanism with the selector incorporated into the trigger mechanism would be very useful. The weapon should be capable of both burst fire and fully automatic fire. Ideally the burst fire should be at a high cyclic rate and fully automatic fire at a lower one. This feature will depend on how simply this can be achieved. The need for this will be dependent on how much muzzle movement there is between the firing of the first and second round. It should be possible to give the weapon an optimum rate of fire, as has been done for the Parker Hale IDW. Rate of fire of the IDW is specially selected so that the weapon fires every shot at exactly the same moment of its oscillation so does not climb during automatic fire. The weapon would use both a selector level and a selector trigger. When the lever is set for burst or automatic fire the first pressure on the trigger fires a single round, full pressure fires the rest of the burst. When set for semi-automatic fire the trigger acts as a two stage trigger, with the second pressure firing the round.
The rifle should be capable of launching standard rifle grenades from the muzzle without modification. There should also be provision for fitting a silencer/suppressor.
Barrel should be Chrome lined. A chrome lined barrel may be marginally less accurate than an unlined one but chrome lining makes for easier cleaning and provides resistance to the erosive effects of full automatic fire, so is more suitable for military use. Barrels can be easily removed should there be a need to change configuration or calibre.
The foregrip should have attachment points (Picantinny rail interface system) for accessories such as Disposable grenade launchers, flame-projectors and shotguns. Systems such as flashlights, laser pointers and electronic sights are common features on modern weapons so provision to incorporate these should be designed into the weapon. This may mean the weapon incorporates a common dual-redundant battery pack that powers any devices fitted to the weapon.
It should be possible to top up the installed magazine with chargers (Canadian FALs had this feature). This will lighten the soldier's load and allow specialist rounds to be quickly loaded. The chargers would be reloadable but cheap enough to be disposable when on active service. Such chargers should also be capable of loading detached magazines. A magazine filler that assists in the use of chargers to fill detached magazines should be mounted on the rifle at some convenient position such as horizontally on the forward edge of the magazine well. To simplify production this may be cast or moulded as part of the receiver lower.
Magazines should be semi-transparent and capable of being clipped together. Large capacity drums or C-mags should be available for assault and support missions.
The weapons would be modular to have as many parts in common with any SMG and LMG variants. Capability to convert the weapon to use 7.62x39mm ammo and AK magazines would be useful. Also useful would be provision to change the weapon to subsonic .300 Whisperâ rounds. The case of the 6.8x43mm SPC round appears to be large enough to accomodate a heavy 9mm bullet for subsonic/CQB shooting.
One variant would be an H-Bar version with a barrel of 20-24 and an overall length and weight about the same as a FAL rifle. That could serve as either a squad marksman's weapon or a light machine gun. This will replace the OICW or GPMG in lightly armed squads and supplement it in heavily armed ones. Provision of an alternate receiver upper could create a belt-feed LMG version that can still use magazines, along the lines of the Negev or Ares Shrike.
A very useful feature for a H-Bar variant would be the Balanced Automatic Recoil System developed for the AK-107/108 rifles(right). The longer barrel of the H-Bar would still permit the use of rifle grenades.
The basic rifle should be constructed to be very lightweight. Using modern materials a rifle of around 5lbs weight is not unlikely. In fact some versions of the AR-15 using carbon fibre are already lighter than this. Modern combat rifles have a considerable quantity of add-ons that are usually fitted as standard. These include underbarrel grenade launchers, flashlights and more sophisticated sights. By using a very light weapon as the foundation these capabilities can be included without the final package becoming too heavy. The weight of the add-ons tempers any excessive recoil that would be experienced with a light weapon. Without the add-on components the weapon would be useful for troops that have to carry a lot of other equipment, but mainly use their rifles for self-defence. Examples of such troops might be Long Range Reconnaissance or Surveillance specialists or dismounted mortar crewmen. In size and weight such a weapon would be similar to the M1A1 carbine. Recoil with the more powerful round would be higher than that of a .30 Carbine, but not excessively so, and this would not be a major drawback to personnel who's weapons are often carried and seldom shot. These very light versions are unlikely to be used for grenade launching, so a larger diameter more efficient muzzle brake can be fitted. Recon troops are likely to be issued with Suppressors which will have a similar recoil moderating effect. At Infantry Rifle Platoon level rifles will be put to more aggressive use and if fittings such as underbarrel grenade launchers are not fitted the gun can be ballasted with heavier furniture. This will give it better control for automatic fire and reduce the felt recoil when muzzle-launching Rifle-grenades. A very light version for use as a defensive weapon for non-combat troops would also be available.