Im not too sure the RAN would be too keen on whipping 60 year old bits of kit out of museums and bolting them onto their ships.

 

For one i dont think the navy would just keep the hundreds if not thousands of 20mm's in storage since the 40's and secondly while the contemporary 40mm Bofors has survived into the 21C not too many 1st or even 2nd world navies would still have the old 20mm weapons in front line service.

 

I would personally prefer to see the GAU-19/A .50 or a similar system replacing the M2's or even the naval variant of the ASLAV's M242 25mm chain gun but it seems that the M2 is more than capable of firing warning shots at illegal fishing vessels.

 

Cheers.

The role of these guns changed. Oerlikon 20mm guns were used as secondary AA guns to shoot down Japanese Kamikaze. There wasn't many .50Cals as AA guns on boards at that time. 20mm guns are heavy and a bitch to maintain, while .50 Cal guns are light (relatively) and easy to keep. Nowadays, nobody is using those 20mm guns for AA purposes. You have missiles, why bother using guns? Besides, the R2 shoots more shells per minute than, I don't know, probably 50 Oerlikon 20mm guns.

 

In the meantime, .50 Cal BMGs are used as security guns for ships to defeat pirates, DPRK spy ships or Allah Akbar boats.

i have to admit that im not up to speed on modern auto cannon/ bushmaster style weapons. however i still wouldve thought a heavier ?explosive round of the 20mm would be more effective at longer ranges than a .50cal. i guess it reflects the old WW2 aeroplane debate, "whats better, cannons or multiple .50s"?

in recent times there have been developments made in explsoive rounds for .50cal, (I think RUAG have done some fairly interesting dev).  But generally one of the principle advantages of 20mm over 12.7m is that the former has a greater variety of explosive heads as well as a more doverse range of warheads available.  eg, its a waste of time using a cavitating warhead on a .50cal, but its certainly the opposite for a 20mm as it opens up opportunities for brown water, protected water, anti-mine, ant-pers work - as well as assoc with hypersonic benefits.

the czechs and south africans did some interesting  development of 20mm anti-pers "sniper" weapons, but they weren't exactly portable weapons.

 

I don't think its just a question of "cannons or multiple .50's, its more an issue of kill and usage relevance.

i wonder who wouldve thought of a USS COLE style attack prior to it happening, hence 20mm lost favour. then everyone fell into a monkey-see-monkey-do fashion?

is it time to think again, or am i a silly bugga? :-)

the irony of the USS Cole was that although the USN did have ROE's in place, they weren't in gear. the weakest link was human.  But after much internal gnashing and as a result, the ROE's and procedures are now even more robust.

IIRC they had prior warning re an event but it got lost in comms and relevance was dismissed.  nit 100% on that, so I wouldn't take it as gospel until someone else confirms

to my mind if ever HMAS SOMETHING had to repel a fast assualt by a speedboat (ala USS COLE) im sure in the end everyone would wish for, and get, a better result from a flex mounted 20mm cannon than a flex mounted .50cal. afterall it was used widely in the AA role. im also sure it'll be far more intimidating in the above stated 'shot over the bow' scenario too.

i guess one way to look at is is the pure metric of stopping power.

20mm with explosive warhead or proximity timer can airburst in front of or above a hyperactive skimmer bent on promoting uncivilised behaviour.  either way, there are multiple points of hurt and damage, be it crew, comms or structural integrity

20mm with explosive warhead can kinetic kill and hurt any small hull, ispo facto, there are multiple points of hurt and damage, be it crew, comms or structural integrity

20mm can engage further out depending on the ROE onion zones

20mm AP through an engine block or an outboard is going to stop that motor dead.  They'll only be continuing on due to momentum - not because of robust engineering

 

50cal has a hard time achieving the same effect - but its got the advantage of relative portability and thus it can be manhandled into position virtually anywhere you can bolt a pintle.

 

I had a walk around a VLS Ticonderoga CG several years back and remember that it had a 25mm bushmaster mounted on each beam for defence against speed boats as used by Iran during the Tanker War.

On the Tico's 25mm guns, those are Mk38s, effectively an M242 Bushmaster Chain Gun in a pintle-type free mounting (manual traverse & elevation).

There's also another version, actually more of a turret/weapons station, featuring stabilization. It can be mounted on the fore deck of many small craft, and some even have a 40mm grenade launcher in the mounting with them.

 

On the explosive 50-cal rounds,

both RUAG and NAMMO (Raufoss) had some designs going.

NAMMO seems content with its MP multi purpose frangible rounds.

They used to have a series of pics showing its effects (fragmentation) thru several sheets of aircraft-grade aluminum plate (or duralumin or something like that), but wasn't able to locate it last time I browsed their site.

 

As per 20mm guns,

the Wiki article on the original 20mm Oerlikon of WW2 fame isn't all that bad, link

one of the things I should clarify with my comments, is that when I made ref to 20mm I wasn't being calibre restrictive.  ie I was including sub 30mm as well. ie 20mm-30mm opportunities.

 

 

I'm willing to bet all those several hundreds (thousands even?) of Oerlikon 20mm weren't so much clapped out as they were scrapped out.

There probably were, post-WW2, more and more of them crated up as the USN, RN, and others started wider adoption of 40mm Bofors guns in twin, quad, even 8 gun mounts, as well as the 76mm automatic guns with their early proximity fuzed ammo (at the time, the engineers could only manage to get a functional fuze down to 76mm sized.

 

Sure, there were numerous second- and third-tier navies that would've kept some 20mm's around, but as SAMs became more commonplace, those guns most likely found either the scrap heap & were smeltered down, or became part of some landfill or coral reef somewhere.

 

Matter of fact, the current German Navy did use 20mm guns until fairly recently, but Rheinmetall Rh202 derivatives I believe.

Those and the 40mm guns, on just about every German Navy vessel equipped so, have been replaced by the BK27 in its MLG27 naval mount, or are in the process of doing so now.

 

link

pulled from Bug via T5C .......

 

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As if this new Merkava Mk IV BAZ is not armed enough, we now have a LASER gun added to the R-OWS (Remote Over Head Weapons System) that is able to defeat and 'neutralize' Both IED and the newer EFP road side anti vehicle bombs. This system saw combat last year on Merkava APC's called Namer (Leopard) and was successfully deployed and neutralized many Hezbo road side devices. It is now being installed on Stryker and Up-Armed HUMVEE vehicles in both Iraq & Afghanistan as well as Merkava Mk IV BAZ MBT's right on the Tel Hashomer assembly line outside Tel Aviv.


THOR R-OWS with Chain Gun and Chemical anti IED Laser Gun

Why don't we keep the Bofors from the Fremantle Class.  I was watching Sea Patrol, potentially the finest drama about the Navy, since JAG.

 

With two shots they achieved quite spectacular results, huge explosion, disabled the ships engine room and two bad guys managed to walk out unscathed and surrender.

 

Surely the Bofor's is a much better piece of kit.