5.56×45mm NATO Conversion Kit for MG 42/59 (?)

[Christopher Wang]

According to McNab (2012), the Stabilimento Militare Armi Leggere Terni or SMALT had produced a conversion kit to adapt the MG 42/59 GPMG (Italy's license-produced version of the MG 42 / MG 3) to 5.56×45mm NATO ammunition (p. 25). Uncited entries on Wikipedia claimed that the conversion kit consists of a new barrel, bolt head, feed opening and cover, recoil-enhancing element, and a lighter bolt. It is also claimed that the weight of the modified 5.56×45mm MG 42/59 GPMG remains unchanged from the original version.


SOURCE: McNab, C. (2012). MG 34 and MG 42 Machine Guns. Osprey Publishing.

An online search on Google has yielded little to no information on such a conversion kit for the MG 42/59. Does anyone have any information and pictures about this conversion kit? Did such a conversion kit actually existed?

 

[riggerrob]

In Spain CETME (?) built a belt-fed 5.56mm machinegun that resembled an MG42 from a distance. Up close, it was significantly smaller than the original Nazi Germany MG42.

 

[TomS]

In Spain CETME (?) built a belt-fed 5.56mm machinegun that resembled an MG42 from a distance. Up close, it was significantly smaller than the original Nazi Germany MG42.

The Ameli. It's also quite different internally, being a roller-delayed blowback gun rather than a fully locked short-recoil design. Which means, especially, that the Ameli's barrel doesn't move. It's essentially an HK machine gun with MG 42 style furniture.

 

[Scott Kenny]

The Ameli. It's also quite different internally, being a roller-delayed blowback gun rather than a fully locked short-recoil design. Which means, especially, that the Ameli's barrel doesn't move. It's essentially an HK machine gun with MG 42 style furniture.

The Ameli is really a 5.56 MG45(v). The roller delayed mechanism was intended to replace the MG42 because it's simpler.

 

[Apophenia]

... Did such a conversion kit actually existed?

That SMALT 5.56 MG 42/59 conversion kit did exist. But the Esercito saw no advantage in it. The switch to 5.56 increased the ROF - which was already seen as a problem with the MG 42/59. After faffing about with the troublesome 5.56 mm Beretta AS70 LMG as a potential squad weapon and replacement for the MG 42/59, the Esercito finally alit upon a Beretta-licensed FN Minimi instead.

5.56 AMELI

Although CETME began development of the AMELI, the alphabet soup gets a little convoluted. By the time the AMELI emerged in 1981, CETME had been privatized as CETMESA (Compañía Tecnológica Materiales Especiales SA). When the Ejército adopted AMELI as its MG 82 section support weapon in 1982, production fell under the senior state-owned enterprise - ENSAB (Empresa Nacional Santa Bárbara de Industrias Militares SA or the Santa Bárbara National Company of Military Industries). By 1984, ENSAB had absorbed CETMESA altogether.

ENSAB became ENSB (by which AMELI is now know) but, in another privatization drive, ENSB was gobbled up by US interests in 2001 to become the Santa Bárbara Sistemas SA division of General Dynamics - now GDELS SBS. IIRC, GD was primarily interested in the former Santa Bárbara Blindados (SBB). The La Coruña factory where was closed down shortly after the GD take-over, ending MG 82 production.

-- https://armourersbench.com/2018/11/30/the-cetme-ameli-light-machine-gun/
-- https://cetme.foroactivo.com/t394-h...entro-estudios-tecnicos-materiales-especiales
-- https://www.elradar.es/empresa-nacional-santa-barbara-historia-de-una-privatizacion/

 

[Scott Kenny]

That SMALT 5.56 MG 42/59 conversion kit did exist. But the Esercito saw no advantage in it. The switch to 5.56 increased the ROF - which was already seen as a problem with the MG 42/59. After faffing about with the troublesome 5.56 mm Beretta AS70 LMG as a potential squad weapon and replacement for the MG 42/59, the Esercito finally alit upon a Beretta-licensed FN Minimi instead.

Even higher ROF and not any lighter for the weapon proper.

5.56 AMELI

Although CETME began development of the AMELI, the alphabet soup gets a little convoluted. By the time the AMELI emerged in 1981, CETME had been privatized as CETMESA (Compañía Tecnológica Materiales Especiales SA). When the Ejército adopted AMELI as its MG 82 section support weapon in 1982, production fell under the senior state-owned enterprise - ENSAB (Empresa Nacional Santa Bárbara de Industrias Militares SA or the Santa Bárbara National Company of Military Industries). By 1984, ENSAB had absorbed CETMESA altogether.

ENSAB became ENSB (by which AMELI is now know) but, in another privatization drive, ENSB was gobbled up by US interests in 2001 to become the Santa Bárbara Sistemas SA division of General Dynamics - now GDELS SBS. IIRC, GD was primarily interested in the former Santa Bárbara Blindados (SBB). The La Coruña factory where was closed down shortly after the GD take-over, ending MG 82 production.

-- https://armourersbench.com/2018/11/30/the-cetme-ameli-light-machine-gun/
-- https://cetme.foroactivo.com/t394-h...entro-estudios-tecnicos-materiales-especiales
-- https://www.elradar.es/empresa-nacional-santa-barbara-historia-de-una-privatizacion/

CETME AMELI: 11.7lb belt fed 5.56. The Minimi is 17lbs, 50% heavier.

 

[Christopher Wang]

That SMALT 5.56 MG 42/59 conversion kit did exist. But the Esercito saw no advantage in it. The switch to 5.56 increased the ROF - which was already seen as a problem with the MG 42/59. After faffing about with the troublesome 5.56 mm Beretta AS70 LMG as a potential squad weapon and replacement for the MG 42/59, the Esercito finally alit upon a Beretta-licensed FN Minimi instead.

I don't suppose you know any information sources about the SMALT MG 42/59 conversion kit?

 

[Ingraman]

Most of the information come from old italian military magazines. I just found an old copy of Rivista Italiana Difesa - 02/1996.
Sadly no photos at all.
The conversion kit was shown during a demonstration at SCUOLA MILITARE COLLAUDO ESPERIENZE ARMAMENTI DI NETTUNO (a test center for the Italian Army), togheter with other weapons systems like an underbarrel LP 40mm grenade launcher also from SMAI Terni (never adopted as far as I know).
Minimi was already chosen as the new LMG, but since there were not enough money to replace all the MGs in the infantry units... the conversion kit was still considered.
In the end it was abandoned and infantry units kept standard MG-42/59 in service for many more years until a decent amount of Minimis was finally purchased thanks to Beretta's license production.

 

[Scott Kenny]

Most of the information come from old italian military magazines. I just found an old copy of Rivista Italiana Difesa - 02/1996.
Sadly no photos at all.
The conversion kit was shown during a demonstration at SCUOLA MILITARE COLLAUDO ESPERIENZE ARMAMENTI DI NETTUNO (a test center for the Italian Army), togheter with other weapons systems like an underbarrel LP 40mm grenade launcher also from SMAI Terni (never adopted as far as I know).
Minimi was already chosen as the new LMG, but since there were not enough money to replace all the MGs in the infantry units... the conversion kit was still considered.
In the end it was abandoned and infantry units kept standard MG-42/59 in service for many more years until a decent amount of Minimis was finally purchased thanks to Beretta's license production.

There's honestly nothing wrong with keeping a mix of 5.56 basic rifles and 7.62mm machine guns in the squad. It's what ended up happening a lot in Afghanistan.

I'd want the lowest ROF the armorers could work out of an MG42, though.

 

[HoHun]

Hi,

I'd want the lowest ROF the armorers could work out of an MG42, though.

According to a 1960 Bundeswehr pocket manual, the MG 42 (which in the context actually refers to 7.62 x 51 mm variant of the MG 42 ... the MG 3 was only introduced later), the practical maximum rate of fire a MG gunner was expected to deliver was 60 - 80 rounds in 30 seconds in bursts of 3 to 5 rounds, or about one burst every 1.7 seconds.

That's not so different from the WW2 Bren gun's 120 rounds per minute in 4 to 5 round bursts, considering that the Bren gun required a magazine change after each 30 rounds. (Relying on https://en.wikipedia.org/wiki/Bren_light_machine_gun#cite_ref-21 here, which quotes Pamphlet No. 4, Light Machine Gun, Small Arms Training, Vol 1, War Office, June 1939.)

So I guess the high theoretical rate of fire of the MG 42 is a bit overrated when it comes to its impact on practical ammunition consumption, but I am definitely not an expert on infantry weapons and could easily be wrong here!

Regards

Henning (HoHun)

 

[Scott Kenny]

According to a 1960 Bundeswehr pocket manual, the MG 42 (which in the context actually refers to 7.62 x 51 mm variant of the MG 42 ... the MG 3 was only introduced later), the practical maximum rate of fire a MG gunner was expected to deliver was 60 - 80 rounds in 30 seconds in bursts of 3 to 5 rounds, or about one burst every 1.7 seconds.

That's not so different from the WW2 Bren gun's 120 rounds per minute in 4 to 5 round bursts, considering that the Bren gun required a magazine change after each 30 rounds. (Relying on https://en.wikipedia.org/wiki/Bren_light_machine_gun#cite_ref-21 here, which quotes Pamphlet No. 4, Light Machine Gun, Small Arms Training, Vol 1, War Office, June 1939.)

So I guess the high theoretical rate of fire of the MG 42 is a bit overrated when it comes to its impact on practical ammunition consumption, but I am definitely not an expert on infantry weapons and could easily be wrong here!

A slower rate of fire makes it easier to shoot those 3-5rd bursts.

 

[HoHun]

Hi,

A slower rate of fire makes it easier to shoot those 3-5rd bursts.

Ah, I see. You might well be right, though it's worth noting that with the MG 3, the Bundeswehr did not acquire on of the rate-of-fire reduced variants that were available under the MG 42/59 name. (Rate of fire on the MG 3 was slightly reduced compared to the original MG 42, but I am not sure that was a deliberate design choice as the bolt carrier group had some improvements that apparently increased mass a little.

As the Bundeswehr certainly had institutional knowledge of the German WW2 experience, I believe that would indicate they didn't consider the high rate of fire an issue, but I am not sure of what the explanation for this would be.

One interesting bit Ian McCollum mentioned in several of his Forgotten Weapons videos, I believe in the context of the FAMAS assault rifle, is that the controllability of a gun when firing bursts is tied to the resonant frequency of the human geometry, and at least for one case (using 5.56 mm ammunition), it was found to be in the 800 rpm realm. That was the worst rate of fire for accuracy, going either above or below it would improve it. I presume the frequency also depends on the mass of the weapon, and of course humans are individually different and can use a wide variety of stances, so that 800 rpm number probably doesn't transfer directly to a GPMG like the MG 42.

It's worth noting that in the Bundeswehr, the MG 42 was usually given to the big, beefy guys! That might have been owed to the fact that they had an easier time carrying the heavier weapon, but if body mass determines resonant frequency of the man-machine pairing, it might also have helped accuracy. Few explanations were provided in the Bundeswehr, and of those that were, at least 50% were obvious nonsense!

So, I'd be highly curious about the rate of fire and the accuracy of the MG 42/59 conversion to 5.56 mm ...

Regards,

Henning (HoHun)

 

[Shoes31]

A slower rate of fire makes it easier to shoot those 3-5rd bursts.

I remember reading about very high ROF making short bursts extremely accurate downrange. The idea is that your body cannot react fast enough to the impulse generated at those high ROF so the operator can't jerk or try and correct aiming while firing. Thats why the original MG42 was around 1,500 to 1,800 RPM - by the time you can react to the impulse of the shot and screw up your aim you've already shot 6-8 rounds.

IIRC ROF for machine guns tends to come down to two areas - the 500 to 600 RPM range as around that RPM your body reaction time is able to stay in tune with the recoil impulse and then the uber high RPM to get burst fire downrange accurately. Going above or below lowers accuracy because of the operator trying to compensate for the muzzle rise poorly.

 

[Ingraman]

A scan from another italian military magazine. No additional information about the 5.56 conversion, except the low price and the heavy weight.
The first photo is a Commando 60mm mortar made by the Piacenza Arsenal.
The 40mm LP GL made by the Terni Arsenal is said to cost half of the other commercially available products.