4 ms·

Sniper rifles are firing a single shot, the bullet is smaller, and snipers can take significant time to prepare. I've heard of snipers firing a few hundred yard

Sniper rifles are firing a single shot, the bullet is smaller, and snipers can take significant time to prepare. I've heard of snipers firing a few hundred yards away from their target first to see exactly how their shot will be affected by drop and wind and only then aiming at their target. Sniper rifles have much less stress on them imposed by firing the cartridge than a Phalanx; a 12.7x99mm cartridge is nothing compared to 20x102mm. Finally, a sniper is firing a single carefully aimed shot; a Phalanx is firing 75 rounds a second from six rotating barrels.

wolverine876 3y ago
How does that reduce effectiveness of a Phalanx against a drone? With all that metal flying, the pinpoint accuracy problem seems solved.
- icegreentea2 3y ago
  The M61 (the gun the Phalanx is built around) apparently has a 80% dispersion of ~5 milliradians (see this amazing reddit post complaining about DCS - note that the evidence points to a range of values - I think 5 milliradians is a fair summary https://old.reddit.com/r/hoggit/comments/eyddn3/m61_and_gau8_dispersion_values_are_wrong_what_ive/ https://old.reddit.com/r/hoggit/comments/eyddn3/m61_and_gau8... ). At 1500m that works out to a 75cm radius (I'm pretty sure its radius...) disc. Assuming your firing at a missile flying right at you, and assuming a Cold War era threat (so say a Kh-22 fired from a Tu-22M), you're talking about a 92cm diameter target (46cm radius) that you're trying to hit. In reality, things are worse because in addition to dispersion, your actual point of aim of your stream of bullets will be effected by external factors (like wind). You can see how in the scenario layed out above, you do actually have what seems to be a reasonable chance of landing a few hits when you're spewing out hundreds of rounds within seconds. But you can also see how quickly the odds go to crap as you push the range further and further. I think that gets to the reality of what the "effective range" value is. It is a rule of thumb designed to help weapons officers quickly determine how best to react in a scenario. Remember that CIWS was envisioned to be deployed in a scenario where USN ships would be subject to saturation attacks by supersonic anti-ship missiles from multiple bearings and sources. Phalanx itself only has a magazine of ~1000 rounds, which is good for maybe only 10s of firing, so you really do need to conserve ammo.

wolverine876 3y ago

How does that reduce effectiveness of a Phalanx against a drone? With all that metal flying, the pinpoint accuracy problem seems solved.

icegreentea2 3y ago
The M61 (the gun the Phalanx is built around) apparently has a 80% dispersion of ~5 milliradians (see this amazing reddit post complaining about DCS - note that the evidence points to a range of values - I think 5 milliradians is a fair summary https://old.reddit.com/r/hoggit/comments/eyddn3/m61_and_gau8_dispersion_values_are_wrong_what_ive/ https://old.reddit.com/r/hoggit/comments/eyddn3/m61_and_gau8... ). At 1500m that works out to a 75cm radius (I'm pretty sure its radius...) disc. Assuming your firing at a missile flying right at you, and assuming a Cold War era threat (so say a Kh-22 fired from a Tu-22M), you're talking about a 92cm diameter target (46cm radius) that you're trying to hit. In reality, things are worse because in addition to dispersion, your actual point of aim of your stream of bullets will be effected by external factors (like wind). You can see how in the scenario layed out above, you do actually have what seems to be a reasonable chance of landing a few hits when you're spewing out hundreds of rounds within seconds. But you can also see how quickly the odds go to crap as you push the range further and further. I think that gets to the reality of what the "effective range" value is. It is a rule of thumb designed to help weapons officers quickly determine how best to react in a scenario. Remember that CIWS was envisioned to be deployed in a scenario where USN ships would be subject to saturation attacks by supersonic anti-ship missiles from multiple bearings and sources. Phalanx itself only has a magazine of ~1000 rounds, which is good for maybe only 10s of firing, so you really do need to conserve ammo.