FN FNC: Predecessor of SCAR Rifle

FN FNC: Predecessor of SCAR Rifle
By Todd Burgreen

The FN SCAR rifles – Mk 16 (5.56mm) and Mk 17 (7.62x51mm) – are recognized by many as being the current epitome of assault rifle design. Design principles centered on ergonomics, modularity, adaptability, and reliability are all present in the SCAR family of weapons. The FN SCAR did not erupt fresh off the FN engineer’s computers without having some homage to pay to predecessors. While the SCAR is no doubt a highly refined rifle bringing together many facets of design including its own unique contributions, it too has a traceable heritage in the FN Herstal family tree. The SCAR can be viewed as the continuation of FN efforts that span decades to bring to market a successful 5.56mm design that would rival the success of the big brother FAL chambered in 7.62x51. The FN FNC (Fabrique Nationale Carabine), the rifle reviewed herein, can be viewed as the precursor for the FN SCAR.

There are very few examples of successful “start from a clean slate” weapon designs. This is not to take away from designers who borrow or modify previous efforts. This is the natural progression involving most technology advances. A fair generalization is that weapon designs constantly evolve. This is for a variety of reasons stemming mainly from market and technological impulses/pressures magnified by ever changing mission requirements of end users. Most “gun people” realize this and do not succumb to manufacturer advertisements heralding their latest product as the “game” changing design of the century making all others obsolete. The FN SCAR is the poster child of this design modification process.

The FN FNC is itself directly connected to the not very well received FN CAL (Carabine Automatique Légère or Light Automatic Carbine). Research indicates that the FN CAL, introduced in the late 1960s, was an early FN attempt to produce an assault rifle chambered for the US 5.56mm cartridge. The FN CAL rifle was designed with mass production in mind, with extensive use of steel stampings and plastics. While bearing a certain resemblance to the FN FAL rifle, its operating principles were different. However, the production life of the FN CAL was relatively short; only about 12,000 of FN CAL rifles were manufactured before FN closed the CAL production line in 1977 switching to a more promising design—the FN FNC. Most of the FN CAL weapons were sold in Latin America and Africa. The main problems, associated with FN CAL rifles, were complexity of manufacture, insufficient reliability and somewhat complex maintenance procedures. The FN CAL death knell occurred when it did not perform well in the early 1970s NATO rifle trials held in France; this sped along the impetuous to find its replacement.

The FN FNC evolved out of the FN CAL failure. The FN FNC design was not only more cost effective for FN due to manufacturing techniques employed, but also more importantly for FN proved a much more viable weapon. The FN FNC was developed over a two year period after the FN CAL’s withdrawal from the NATO rifle trials mentioned above. The FN FNC was entered into the 1976 Swedish arms tests and performed well. In fact, the FNC was eventually adapted by the Belgian armed forces as well as Sweden (AK-5) and Indonesia (Pindad SS1) militaries.

I accessed a semiautomatic FN FNC Para for testing. Range evaluation of the FN FNC began with an orientation and introduction of the rifle from its owners Jeff and Gretchen Burch. Jeff and Gretchen are the proprietors of the training entity “Take Aim LLC” as well as contractors for FNH USA. Jeff succinctly discussed the basic features and controls of the FN FNC including maintenance procedures, field stripping and other points of interest related to the FN FNC.

One item that was constantly discovered during research on this article was the situation of more auto sears being available on the NFRTR than actual FN FNC rifles imported into the U.S. before the 1986 ban. This would lead one to believe legally converting a semi-auto FNC to select fire would be a worthy path to Class 3 weapon ownership. The most commonly accepted number of FN FNCs being in country is 6,000 with 5,000 of these being the Para model with folding stock. S&H Firearms was at the forefront of the FN FNC conversion process here in the U.S. as they were sole source of auto sears for the FNC from 1986 onward. A reading of different sources, including court documents involving a lawsuit related to FNC sears, would indicate that over abundance of auto sears for the FNC is not to the extent bandied about in forums and gunshow gossip.

Descriptions uncovered detail how the original conversion method of a semi-auto FNC to accommodate the auto sear required machining. The FN FNC has to have a section of the lower receiver milled away near the “magwell” and a sear pin hole drilled all the way through the lower receiver. The bolt then has to have a sear trip welded onto it and the fire-control group modified to properly interact with the sear. Written description of process shows it very similar to what is considered illegal when done with an AR-15 to M16 conversion. What makes the difference between a legal FNC conversion and an illegal AR-15 conversion is that the location where the conversion FNC sear is installed in the lower receiver is not where the "factory" FN installed sear would go. Over the years BATF Technical Branch influenced the FNC sear conversion process to eliminate the milling and drilling aspect. This was due to implications of the FNC process impacting other weapon decisions related to sear modifications. Eventually, S&H started doing conversions without drilling a hole through the lower receiver by making an encasement for the sear to sit in and utilizing a set screw to install it into the milled area of the lower receiver. Further confusion into the process was introduced in a May 2008 ATF letter ruling that the upper of the FNC would be considered the registered part of the rifle. This allowed for a return back to original sear conversion process of drilling the lower receiver. Today, thanks to the intervention of the NFATCA, the upper is considered the firearm receiver, and the lowers are treated as trigger packs. This saved millions of dollars for legitimate owners of FNC Sear guns who might otherwise have found their sears to be considered improperly installed, and would be contraband.

The FN FNC utilizes the same trigger mechanism as found on the FN CAL that preceded it. Of which an excellent description was found and incorporated here, “There are two spring-loaded sears – the rear sear is secondary. An auto safety sear in front holds the hammer at all times until locking has been completed. Pulling the trigger releases the hammer to fire a round. In semiautomatic fire the recoiling bolt carrier is held back by the secondary sear. When the trigger is released, both sears move with the hammer caught by the auto safety sear. Placing the selector lever on automatic locks the secondary sear so that it becomes inoperative. Each time the bolt carrier goes into battery the auto safety sear releases the hammer. The cycle continues until the trigger is released and the hammer is once more captured by the primary sear. Cyclic rate in full-automatic fire is 625-700 rpm with the FNC.”

Returning to our introductory paragraph of how weapon designs are often derived from predecessors, the FN FNC can be viewed as an amalgamation of some of the better features of the AK47 and M16 rifles. There can be little doubt that the long-stroke piston driven FN FNC with its rotating bolt riding in a carrier was stimulated by Kalashnikov’s AK47. There is nothing wrong with this. The Swiss were traveling the same path with their SIG 550/551 series. Patterned after the Kalashnikov system, the rotary bolt has two locking lugs, which run in guide rails welded onto the upper receiver walls and the feed lug on the bottom of the bolt head drives the magazine's top round into the chamber. Rotary movement is begun and primary extraction is provided by a small lug on top of the bolt head. The FNC bolt carrier can be separated from the operating rod when the rifle is disassembled. This is a variation from the original AK design. The FNC’s upper and lower receivers hinge open similarly to the AR-15/M16

FN sought to make use of stampings and plastics in the FNC for cost saving purposes. However, FN also decided to take advantage of emerging CNC machine and industrial robot technology to maximize quality in certain parts of its construction. The FNC’s upper receiver is made from robot welded, sheet-metal construction and the lower from aluminum alloy. Most of the exterior metal parts of the rifle are coated with what appears to be black baked on enamel finish. The enamel finish has proven durable and resistant to rust corrosion even in tropical climates. The gas system is adjustable with two settings—normal and adverse. The FNC’s breech is locked by the rotating bolt, with the two lugs interfacing into the barrel extension. The bolt and carrier are examples of only a few items on the FNC needing precision machining in the manufacturing process. The piston head is welded to a hollow extension, which contains the front portion of the recoil spring and guide rod assembly. The piston extension is pinched in the center and pierced by a hole which retains a roll-pin on the end of the guide rod. The piston head and extension, as well as the gas port block, barrel bore and chamber, are hard-chrome plated by an automated process developed by FN. A sheet-metal backplate is attached to the rear of the guide rod. Multiple robot welds have been used to mount the bolt carrier to the piston extension. Another roll-pin holds the firing pin in place on the bolt carrier and a 3-inch firing-pin spring fits tightly over the pin itself.

The FN FNC Para weighs in at 8.5 pounds and measures 39.25 inches with the folding Para stock deployed and 30 inches folded. The FNC’s 17.6 inch barrel features 1:7 rifling twist with 1:12 twist barrels also available from FN. The FNC features the same flash hider as the FAL – literally as it accepts the hollow handled type FAL bayonet. The FNC has a true 5.56mm chamber enabling it to fire both 5.56mm and .223Rem loads. FN designed a steel magazine very similar to the AR-15 magazine – in fact the FNC can utilize AR magazines. Original FNC magazines are costly and somewhat difficult to find; however numerous reports attribute the FNC as having better reliability when teamed with the FNC magazines. The FNC does not hold the bolt open after the last round is fired. The FNC fixed buttstock and folding Para are derived from its FN FAL big brother and are recognized as excellent examples of both types of stock. The FNC handguard is a two piece affair with heat shields riveted into place. The handguard is well configured with a rib molded in front to prevent the shooter’s hand from sliding forward and contacting the heat shield around the gas regulator and/or barrel. During range evaluation, the handguard proved comfortable and effective at isolating the shooter’s hand from heat even after multiple magazine dumps.

The FNC’s bolt handle fits in a hole on the right side of the bolt carrier and is canted slightly upward. This cant allows for it to be retracted with the left hand reaching over the top of the receiver. An ejection port and retracting handle slot are cut into the right side and a complicated six-component dust cover is mounted over the rear portion of the cocking handle's slot. Spring-loaded, it remains closed at all times moving out of the way during firing only to spring back over the slot as soon as bolt moves forward. The FN FNC iron sights consist of a hooded front over the gas block and a rear diopter sight with flip-up 250M and 400M apertures also protected by metal “ears.” The front sight is adjustable for elevation and rear sight for windage with the caveat that a proprietary tool or pliers are needed. As a sign of emerging tactics and techniques in the late 1970s, the FN FNC was designed to accommodate a proprietary scope mount making use of a notch on top of the barrel extension block and a fork in front of the rear sight. NATO specified optics could be used with the scope mount. An adapter is available as well to allow use of more typical scope tubes.

Testing of the Burch’s FN FNC Para utilized Black Hills new and remanufactured 55gr FMJ, Federal 55gr FMJ, and Winchester 55gr FMJ. The bulk of firing was with Black Hills Ammunition 55gr FMJ. Accuracy with the FN FNC was more than acceptable with the open sights producing 1-2.5 inch groups at 50 yards with the ammunition tested. A taut trigger with nearly 10 pound pull was not the most helpful in achieving full accuracy potential. A couple of familiar range drills were used while evaluating the FN FNC. One drill began by engaging multiple steel TacStrike targets arranged between 35 yards and 115 yards. Targets were engaged five times each starting from the standing, moving to another locating, five more rounds from kneeling, and finally moving yet again and transitioning to the prone with five more rounds reloading as necessary. The layout and availability of various steel targets and simulated barricades at Echo Valley Training Center proved convenient in allowing for firearm evaluation.

There was something about the lower receiver’s aesthetics that stood out in terms of its appearance that evaluators could not quite put a finger on – until it was time to do magazine changes that is. The FN FNC’s magazine well is neither flared nor beveled to provide user with a tactile aid during reloads; a small detail yet valid observation of an omission related to the FN FNC design. The magazine catch release button is located on the right side in similar fashion as the AR-15/M16 and can be reached by the trigger finger. The FNC selector lever is located on the left side just above the pistol grip as is found on the FAL. As with the FAL, a user will find it nearly impossible to manipulate it with the right thumb finding it more prudent to use the support hand for selector lever placement between fire, safety, and if select-fire model, three-shot burst or automatic.

Unsurprisingly, considering the 10 pound weight of the FN FNC with a loaded magazine, recoil impulse of the FNC was negligible even during rapid strings of fire. With that said, the FN FNC handled well during evaluation drills even when maneuvering around barricades or moving between firing points at Echo Valley Training Center. This indicates a well balanced rifle. Just to keep things in perspective, an old FN advertisement was found touting how the FN FNC with 200 rounds of ammunition was still lighter than a “typical” 7.62x51mm battle rifle with only 50 rounds of ammunition.

The FN FNC offers its user a chance to own and use a rifle different than the prototypical AR or AK pattern rifles so common today. A certain satisfaction will be gained by knowing the FN FNC heritage and how it incorporates features from both ARs and AKs combined with its own nuances. This satisfaction is heightened considering the FNC’s place in the FN family tree hierarchy; not to mention the FN FNC’s viability as a candidate for conversion into a Class 3 weapon.

Sites of Interest:

Take Aim LLC
(540) 931-5396
www.takeaimllc.com