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Military Guns and Ammunition

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This is intended for people interested in the subject of military guns and their ammunition, with emphasis on automatic weapons, particularly in larger calibres (12.7+mm).

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Importance of Naval Guns on a Modern Warship   Naval Guns

Started 19-Aug by Greg (N9NWO); 8662 views.
In reply toRe: msg 27
Mr. T (MrT4)

From: Mr. T (MrT4)

7-Sep

gatnerd

From: gatnerd

7-Sep

From what I could see, ORKA was first (and more similar to what DARPA envisioned - a sort of cannon fired 'glide missile'). This would probably be a better option for highly maneuverable targets like missiles.

L3's H4 is a simpler, likely cheaper option. It appears from the video to be a shell, with some sort of internal rotor that helps course correct the shell / counter the natural dispersion of the gun on a moving ship. 

Both options - and the future ability to scale for 76mm and 5" guns - point to a continuing utility for Naval guns. Especially as a last line of defense against incoming anti-ship missile threats. 

Also makes me wonder about the potential for a 57mm armed Tank/IFV that could provide both ground attack and air defense capability...

In reply toRe: msg 30
gatnerd

From: gatnerd

8-Sep

It seems the Naval Gun is about to get a lot more useful:

https://breakingdefense.com/2018/01/86000-5600-mph-hyper-velocity-missile-defense/

BAE's HVP projectile is $86k for a guided, Hypervelocity projectile capable of shooting down missiles.

A 155mm version of the HVP was recently fired from an Army Howitzer to shoot down a Cruise Missile in training:

https://www.forbes.com/sites/davidaxe/2020/09/06/sci-fi-awesome-a-us-army-howitzer-just-shot-down-a-cruise-missile/#61c7268f209e

Given the cost of Patriot Missile or Standard 6 missile interceptor is $3 million, 35 HVP's could be fired for the same cost. And a ship can carry far more HVP shells then it can carry Missile Interceptors, making it a very compelling last line of defense.

These shells have already been fired from Naval 5" guns.

taschoene

From: taschoene

8-Sep

There are three 57mm guided rounds that were being offered for the USN.

ORKA from BAE has an IR seeker and pop-out fin steering.  It seems fairly conventional but with a flexible seeker that combines autonomous imaging IR and a semi-active laser receiver in one unit.

ALaMO from L3 had some unspecified guidance mode (something RF to judge by the lack of a glass seeker nose) and a fairly unusual mass counterweight course correction system.  It apparently has 4 "bolts" that can be ejected laterally to redirect the round, like the side thrusters in PAC-3.

These two are primarily anti-surface rounds for small boat targets, though both are said to have some anti-air capacity against UAVs and helicopters. ALaMO won a USN competition and is on the way to being type classified and deployed.

MAD-FIRES from Raytheon is a different beast.  It's primarily intended for antiship cruise missile raid defense.  Again, they're being cadgey about guidance, but it seems to be some sort of semi-active radar.  Big selling point seems to be the ability to redirect following rounds in flight to reengage targets that survive a first intercept attempt.  The technology may also have application to Army guns in either 50mm or 30mm.

taschoene

From: taschoene

8-Sep

gatnerd said:

A 155mm version of the HVP was recently fired from an Army Howitzer to shoot down a Cruise Missile in training:

In the same tests, they also fired HVP from a Navy 127mm deck gun and something that looks like a 155mm Advanced Gun System test rig.  

It's been intriguing to watch the pivot; when HVP was announced a few years ago, it was sold as an extended range anti-surface round, but this test shows the transition to air and missile defense has been fairly complete.

gatnerd

From: gatnerd

8-Sep

taschoene said:

It's been intriguing to watch the pivot; when HVP was announced a few years ago, it was sold as an extended range anti-surface round, but this test shows the transition to air and missile defense has been fairly complete.

Thats a welcome change in my book. It shows that the US is finally waking up to the threat posed by Chinas fireworks factory of anti-ship missiles. Of course, if they were really waking up to the threat, they'd be putting more emphasis on Cruise Missile Submarines rather then trying to overcome anti-ship missiles with their current plan of more ships. 

Along those lines, I hope MAD-FIRES comes to fruition, as that does seem the most promising cannon candidate for stopping missiles. 

In reply toRe: msg 34
gatnerd

From: gatnerd

8-Sep

Anti Missile use presents an interesting tradeoff for 'optimum' cannon size.

57mm MK3: 220rpm, 120rd magazine, ~10km range

76mm Super Rapid: 120rpm, 80rd magazine; ~20km range 

5": 20rpm, 20rd magazine, ~50km range

Smaller guns offer higher rate of fire and magazine capacity, but less range for interception, and lower probability of destroying / deflecting the missile. 

Larger provide a further interception range, and higher stopping power, but offer a substantial reduction in magazine capacity and rate of fire. 

taschoene

From: taschoene

8-Sep

I am a bit skeptical about there being such a large difference between 57mm and 76mm effective range.  The usual numbers cited for the two suggest a difference of about 10% when comparing basic HE projectiles. (i.e., 76mm HE surface range about 18 km, 57mm HE surface range about 16 km, with similar ratios for air targets).  The comparison gets a bit muddied because of the sabot rounds on offer for the 76mm gun.  But MAD-FIRES is rocket-assisted, which should mean more range and a much faster/flatter trajectory than ballistic 57mm rounds and probably at least comparable to the saboted 76mm DART rounds.  The PR video that is out there seems to show MAD-FIRES as a hit-to-kill weapon, suggesting that "stopping power" isn't a huge differentiator-- no ASCM is likely to survive a direct impact from a 57mm round intact.

The use case for 127mm-155mm HVP is different, from these others.  It's seen as a potential ASBM/TBM killer, as well as an area defense against high-speed cruise missiles.  It actually plays in the same regime as much larger weapons like SM-6 or Patriot PAC-3. 

HVP may also retain an anti-surface capability, but the HE load is disappointingly small for that role.  OTOH, a smart fuze could make it interesting -- a round that detonates deep inside a ship after penetrating from above could be very nasty.)

Red7272

From: Red7272

8-Sep

gatnerd said:

Also makes me wonder about the potential for a 57mm armed Tank/IFV that could provide both ground attack and air defense capability...

Absolutely amazing no one has thought of that before. 

And let's not mention 57 mm auto grenade launchers with a dual feed APFSDS and airburst/Impact fragmentation/HESH rounds.

gatnerd

From: gatnerd

8-Sep

Red7272 said:

Absolutely amazing no one has thought of that before. 

Those are both really cool. What are the models of those respective machines?

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