Enhanced 12.7x99 - .50 BMG ammunition

Rheinmetall is stating in it’s description of their new “RMG.50” (chain gun?) that the gun can fire regular cartridges and also modified/enhanced versions.

Does anybody know what the modified/enhanced ammunition will be? Sounds much like a cartridge with different ballistics.

I wonder if they are referring to something like an Exacto “guided” cartridge, meaning perhaps that the gun will have upgrades to allow the peripherals needed to control such rds integrated into it?

In Jane’s publications mentioning the gun, there was talk of considerably higher pressure. But I have not seen any hints at how much higher the pressure is planned. And there is the problem of preventing firing such a round in an ordinary cal. .50 gun.

Making the gun electrically powered is of course a big mistake. All tankers know that electrical power “never” fails. So you can aim and fire the Leopard 2 main gun during a power outage, but not Rheinmetall’s newest super machine gun. For infantry use, you have to take a battery with you. Every infantryman knows that batteries “never” fail, especially in cold conditions. Recoil and/or gas pressure available in abundance to operate the gun. But an electrical gimmick is chosen.

On the other hand, I think Rheinmetall is realistic enough to see no guided cal. .50 in the foreseeable future. A video of an unguided fin stabilized tracer projectile, going in a spiral (due to unavoidable asymmetry in aerodynamics) towards the target may be a publicity stunt. But its a very long way towards actually guiding a .50 projectile. Apart from that, cost of a projectile should be lower than cost of the damage it can inflict.

Matt, I think it makes little sense to use a guided projectile in a machine gun. In particular as a certain dispersion is wanted. I remember cases where automatic guns were too precise and got rubber buffers between the gun and the mount in order to enhance the dispersion up to the wanted level.

JPeelen, yes, all those knowing the good old days of analog guns and mounts do know about the problems with electricity.
I think the only justification for an externally driven gun is here in the fact that the sights are also all depending on electricity. Means when electricity is gone the sights and guidance systems are off too. So having then an operational gun is basically useless. It would be like having a howitzer without sights.
This brings us to some more modern ammunition of medium caliber guns which are aiming at the sensors and optics of target aquisition systems which are then to be blinded. Enemy guns will funtion then but will be useless and a mission abort is the result. On a battlefield this counts as a victory.
By now I now two systems:

  • Rheinmetall with it’s “AHEAD” projectiles which are basically modern shrapnel projectiles with air burst capacity and preformed tungsten carbide elements. A shower of these will destroy all optics, sensors and antennas on an enemy vehicle. Leaving the enemy no other option than to retreat.
  • Russia has patented a medium caliber projectile with “optical pollution” capability. The proj. contains a liquid which is agressive acid based material likely mixed with some other particles. Being fired with I assume airburst capability it will enclose an enemy vehicle in an agressive dust of smeary acid and particles rendering optics/sensors permamnetly useless.
    I got carried away again, sorry!

Rheinmetall’s plans for the high-performance .50 were to match the performance of the 14.5mm KPV while the gun could still use standard .50 BMG ammo. Target ballistics were stated as 40-42 g bullets fired at 1,100 m/s or 50 g at 1,000 m/s. This involved a much higher chamber pressure (unspecified) and the use of steel cases. The cartridge case was supposed to be modified so that it could not be fired in a standard .50 gun (which would probably blow up). Exactly how this was to be achieved was never specified, but obvious alternatives are a case with slightly less taper or a sharper shoulder angle, or maybe a semi-rim.

The idea was to offer a longer barrel chambered for the high-pressure ammo (which could also fire .50 BMG) or a standard .50 barrel for anyone who preferred that. I say “was” because the whole project - and especially the high-pressure aspect - seems to have gone quiet.

The choice of external power for the 50 RMG was inevitable, I think, because a gas or recoil action would have real problems functioning reliably with both high-pressure and standard ammo; the internal ballistics would be radically different. Given that the main intended use was in AFVs I don’t see the dependence on electrical power as a problem. The most popular AFV cannon in the west - the Bushmaster Chain Guns from Orbital ATK in 25mm, 30mm and 35mm calibres - all are driven by electric power. So are all of the coaxial 7.62mm MGs fitted to British AFVs.

Tony, thanks for the update!
Rheinmetall is still advertizing the RMG.50 with the upgraded ammo. Let’s see where it will go.