LF 59 is a side character in the manga, she's very much aesthetically similar to L1A1 despite being a tad shorter than her, sporting a pony tail and bangs as her hairstyle.
Due to a her lack of existence further in the manga, we do not know much of her other than first impressions when she was introduced in a brief conversation with L1A1 (Protip: She is somewhat similar) and meeting up with other Spaghetti firearms. Her having a fixed stock give us the fact that she wears standard panties.
In Real Life
The LF 59 was an Italian made indigenous battle rifle, produced by the Fabbrica d'armi Luigi Franchi. Contrary to many misconceptions about her in the firearms community, the LF59 is not an Italian made/licensed FAL. While aesthetically similar, the bolt design, gas operation and receiver construction is very different, along with her specs. The LF59 uses a long stroke gas piston and a tilting bolt that was based off its older sister, the LF58 (Chambered in .30 carbine) which is turn, shows mechanical influences and design influences from the MP43/44 series of German rifles. The rifle is pretty obscure, and there isn't quite alot of media I have found in regards to cover its full development other than 2 magazine articles published in the early 70s that gives a detailed rundown on its mechanical operation and year it was introduced into Italy's battle rifle trials. Franchi has marketed her as an "Assault Rifle" despite accommodating a full powered cartridge, whether they were trying to make heads turn in interest or play a marketing gimmick, we will never know.
She was Franchi's answer for Italy's new military rifle modernization program due to the M1 Garand becoming obsolete in the new generation of warfare introduced by the Cold War. Made completely out of metal stampings,a comfortable pistol grip, selective fire capability and sporting a rate reducer to make her easily controllable in automatic fire, the LF59 was quite on the cutting edge design of firearms for the late 1950s. She competed against Beretta's BM59 rifle which is technically an M1 Garand converted to fire 7.62 NATO,given shorten barrel and being fed a 20 round box magazine with selective fire capability. Despite being well designed, the LF59 was one expensive girl to make, especially when it comes to starting up tooling and equipment to build her. Thanks to the BM59 being a somewhat simple conversion in comparison, she was completely compatible to use the current tooling to make M1 Garands, albeit re-calibrating it was needed for that to happen. Thus the Italians would save much more on their budget using Beretta's design while also continuing to make use of their tooling given from Winchester after WWII. What also had them save alot was the fact that Beretta also offered conversion kits for the existing M1 Garand rifles, further eliminating the cost of retooling (This also benefited foreign militaries with a limited budget).
In the end, Beretta was proclaimed victor again and was given the contract over Franchi, who began to continue production. With its main target lost, Franchi now had to rely on exports and foreign countries to adopt its rifle. This ended up being a marketing failure and as a result, only a few models were constructed for introduction and sampling.
Construction and Design Details
Unlike the FAL, the LF59 is made on a stamp sheet metal receiver, with its stamping pattern and design reminiscent to the LF 58 which in return, leads us back to the MP/Stg 44 series of rifle. It is a two piece stamped receiver that consists of an upper and lower, and hinges open with the removal of one pin. Remove another one and both receiver pieces will be completely separated.
As stated earlier, the rifle uses a bolt assembly which is more or less an LF58 bolt that's been upsized to accommodate the pressure and size of the 7.62 NATO cartridge. Its gas piston and bolt is again, similar to the MP/Stg 44 series of German rifles, and much different in design than the FAL's bolt assembly. However, its mechanical function is basically the same as any other two piece tilting bolt. Unlike the FAL's short stroke piston/tappet system, the LF 59 uses a long stroke piston that is integral to the operating rod. Gas expands into the piston and pushes down towards the rear of the recevier, moving the bolt carrier into the rear with it. The carrier engages a machined ramp in which engages a cam in the bolt. Once pressure has dropped from firing, the bolt is cammed out of engagement from the receiver, unlocking the action and free to move rewards along with the carrier thanks to physics, before reciprocating forward to strip a round from the magazine and chamber it.
Fire Rate Reducer
It also features the same fire rate reducer like its older sister, the LF58 and is considered as quite an effective system despite being unusual according to the authors from the issue of Guns Review, Vol. 11, No. 4, April 1971 and The American Rifleman, Vol. 114, No. 7, July 1971. The LF 59 rate reducer uses a two hammer system, in which a left hammer pivots forward at a 90° angle. At the end of its movement, it releases the right hammer which strikes the firing pin and thus fires the cartridge. This system delays the firing of the weapon which effectively reduces the fire rate to a low 580 rounds per minute versus Beretta's BM59 750 rounds per minute in comparison. This allows the rifle to be controllable in full automatic fire, and let's the shooter maintain on target while even doing long bursts. Along with this system is a recoil spring buffer incorporated in a housing that telescopes inside the bolt carrier and aids in the reducing the travel speed. Both authors of the magazines mentioned above have claimed that the rifle was easily controllable thanks to the reduced rate of fire despite being in a full powered cartridge.
As stated earlier due to being a marketing flop for the international market, Franchi only made very few models. We do not know if they are kept preserved or they have been destroyed, nor has there been any media regarding private ownership of the few models made. If anything, the LF59 can be categorized as a unicorn, if not, unobtainium due to Franchi not continuing its sale worldwide for the military (Not even its design were sold). There is no known documented media of shifting the rifle for civilian sales as well.