Rheinmetall Mk20 20mm S20 Naval Gun in slow motion

This video shows an Hellenic Navy Rheinmetall Mk20 with S20 Naval Gun Mount firing in slow motion. Note how the barrel appears to recoil. At first glance it appears that the gun utilizes a short recoil action like the Rheinmetall MG3 and the MG42. It is actually gas operated but the whole barreled action is mounted on a recoiling platform in order to soften the recoil.

[ Many thanks to Aegeanhawk for the video. ]

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Máté

    Are there any kind of man portable 20mm machine guns?

  • No – the least powerful 20mm ammo in service in an automatic cannon today is the 20×82 round originally developed for the Mauser MG 151/20 aircraft gun in WW2. The gun and ammo are both still made in South Africa as the Vektor GA-1, but the gun weight is around 40 kg (88 lb) – that’s just for the gun, without any sort of mounting.

  • Y-man

    @ Mate: “Man-portable”? As in “AUTOMATIC” fire?

    I don’t think the “man” to carry that has been manufactured yet! Maybe in 200 years? As per Cyborg?

  • sniggol

    I think he made a “funny.” Or in other words, JOKE.

  • cheif emmanuel

    Dear Sir,
    We are an Ammunition and Defence Equipment supplying Company. Covering the coast of West Africa and Nigeria in particular.
    The Nigerian Navy has instructed us to procure for them 20MM and 40MM Naval Guns shipboard, so we want to know if you manufacture these items. If you do manufacture them, kindly send to us your e-copy of the items through PDF Files and their technical details so that we can print it out for analysis or you can send the soft copy through our bellow mentioned Address.
    We want to establish a good business relationship with you.
    While waiting for your quick response
    Yours Faithfully
    Emmanuel Ekwealor
    Managing Director
    Mobil Tel: 234-8033201914 and 234-80-89898919