The MK556 was finalised in September 2020, and it is a fully automatic version of an earlier Haenel design, the CR 223, which was already in limited use by law enforcement agencies since 2017.

[7][8][9] On 14 October 2020, media reports emerged, doubting patent infringements regarding the Bundeswehr MK 556 versions being offered by C.G.

[10] Furthermore, reports regarding patent infringements by Haenel's German box magazine sub-supplier Oberland Arms to the detriment of Magpul Industries emerged.

[23][24] On 21 April 2017, the German Ministry of Defence began its program by putting out a tender to look for a service rifle to replace the Heckler & Koch G36, which has been standard issue in the Bundeswehr since the 1990s.

[26] The System Sturmgewehr Bundeswehr tender was calling for up to 120,000 new rifles including accessories with an estimated total worth of €245 million without VAT (the annual German defence budget for 2020 is €45.646 billion.

The first set of rifles were scheduled to be sent in the final week of October 2020, and the weapon's laser sights, optics, and other attachments in mid-December.

[28] Some of the requirements in the tender were a rifle chambered in 5.56×45mm NATO or 7.62×51mm NATO, with ambidextrous controls, a maximum weight of 3.6 kg (7.94 lb) without a magazine and aiming optics, box magazines with an empty maximum weight of 160 grams (5.6 oz) and a receiver service life of at least 30,000 rounds (barrel 15,000 ball or 7,500 hard-core rounds) as well as interchangeable long- and short-barrel variants.

[29] The rifle was required to be able to function in areas with climate categories A1-3, B1-3, C0-3 and M1-3 according to STANAG 4370 Environmental Testing Procedures without restriction (with the exception of electrical components).

Heckler & Koch criticized the Ministry of Defence in 2019 for the strict requirements, claiming that no 5.56×45mm NATO chambered rifle would have been able to meet the given demands, and also complained about a lack of expertise and neutrality in the proceedings.

[47] The same day the decision was announced, the Ministry of Defence released an official statement:[48] "Assault Rifle System Bundeswehr": Winner of the tender when awarded Berlin, 15 September 2020 The “assault rifle” (System Sturmgewehr Bundeswehr) award procedure has made another major step forward.

On May 14, 2020, the bidders remaining in the System Assault Rifle Basic Weapon award procedure were asked to submit a Best And Final Offer (BAFO).

[55][56] On 9 October 2020, the German Federal Ministry of Defence withdrew their intended award decision, seemingly leaving the potential remaining G36 replacements as either the HK416, HK433 or MK 556 after concluding a re-entered evaluation phase.

According to a letter to Bild from Haenel managing director Olaf Sauer, "the MK 556 is a different rifle with different design features compared with the CR 223 and not addressed in the patent lawsuit.

Haenel was given time until mid-January 2021 to comment on the results of the patent assessment, according to a Bundestag Defence Committee chairpersons briefing.

Haenel managing director Olaf Sauer announced in the Frankfurter Allgemeine Zeitung that he would sue if his company should not be considered.

[71][72][73] On 20 February 2021, Business Insider reported the Bundeswehr in the near future wants to officially announce the revocation of the controversial contract and internally expects that C.G.

Rather, the procurement guidelines of the Bundeswehr expressly oblige the contracting parties to guarantee that their products are free from third-party rights.

[57] According to public procurement lawyers, shortly after the official order revocation announcement on 2 March 2021 by the German Federal Ministry of Defence, the final decision on the new assault rifle could be delayed until all legal actions are exhausted.

[77][78] On 24 April 2021, media reports regarding possible patent infringements by a Heckler & Koch box magazine to the detriment of Magpul Industries emerged.

[80][81][82] On 3 July 2021 German media reported the Federal Armed Forces Procurement Office made serious mistakes when awarding the contract.

Haenel infringed a Heckler & Koch patent and on 20 November 2021 German media reported the complaint procedure at the Düsseldorf Regional Court after a for C.G.

The Regional Court was the final instance in the complaints procedure making it clear that the award decision remains in place.

[90] In June 2022 the Düsseldorf Regional Court rejected Haenel's lawsuit against being excluded from the bidding process, implying that the award decision remains in place.

[92][93] Bundestag (German federal parliament) representatives of the Grüne and FDP political parties protested against awarding the Suhl, Thuringia-based bidder C.G.

Haenel as absurd, claiming that "if you follow the arguments of the Grüne and FDP Bundestag representatives, you shouldn't import oil from Saudi Arabia or buy Mercedes-Benz cars because Kuwait has a stake in Daimler.

"[94] Bundestag representatives of the CDU and CSU political parties, that together with the SPD support the German government, do not share the views of the Grüne and FDP regarding awarding C.G.

According to Deputy Chairman of the Defence Committee of the German federal parliament Karl A. Lamers (CDU) it was "more often the case that investors from all over the world are involved in such companies."

On the same day after the meeting, Der Spiegel and the Frankfurter Allgemeine Zeitung asserted the Bundeswehr has to wait years for a new assault rifle and that almost all Bundestag Defence Committee members fear that one of the two bidders will be expelled of the proceedings by a court because of the various allegations.

[3] With the help of the regulator, the gas system can be adjusted to function reliably with various propellant, projectile, fouling, operating environment and configuration specific pressure behavior.

The integrated rail on the upper receiver and its continuation on the handguard at the 12 o'clock position allows for the adaptation of various aiming optics.