CT: Gun Types and muzzle velocity in TNE FF&S

[snrdg082102]

Evening all,


In CT Striker guns are typed as mortar, low velocity/howitzer, medium velocity, high velocity, or hypervelocity.


TNE Chapter 3 D. Range 1. Direct Fire Range states that hypervelocity smoothbore guns modify the range.


What muzzle velocity in m/s is considered hypervelocity?


I found a couple of sources that indicate that hypervelocity starts somewhere around 2,500 m/s and in atmosphere be a maximum of 4,500 ms.


For that matter what is the muzzle velocity range in m/s for a mortar, low velocity/howitzer, medium velocity, and high velocity guns?

 

[Carlobrand]

Well, let's see:

My reference here says the maximum range of a projectile fired from a gun at 45 degrees is (v^2)/G. That's without air resistance, of course. Air resistance plays a big role and is going to be hard to factor 'cause the bigger guns are going up into thinner air. My math isn't up to that kind of calculation - I understand they generally use range tables or let a computer figure it out nowadays. Anyone with the necessary math skills can calculate from the ranges given in Striker.

So ... let's look at some modern examples. First off, muzzle velocity varies a chunk with the round. HE rounds are fired at lower velocities than APDS rounds from the same gun.

Muzzle velocity of an M-1's Rheinmetal 120mm is between 1600 and 1750 m/s depending on the specific round.

The 1950's era Ordnance QF 20 pounder, of the Centurion tank of that period had a 1400 m/s DS round.

The Soviet D10, mounted on 1950's era T-55 tanks, had a muzzle velocity of 1000 m/s.

A WW-II Sherman Tank's M3 75mm gun had a muzzle velocity of 619 m/s.

A WW-II T-34's 76mm gun had a muzzle velocity of between 600 and 700 m/s, depending on the round. Its APDS round hit 965 m/s.

So, as a ballpark, I'd think medium velocity is in the 600 m/s range, high velocity's in the 1000 m/s range, and hypervelocity's in the 1500+ m/s range. Roughly - which is about as good as it gets for these things.

Modern howitzers, like the US M-109, seem to fall into the 500-600 m/s range. The Soviets in WW-II had a 152mm with a 500 m/s muzzle velocity. Howitzers tend to have a shorter barrel and higher angle of fire than guns.

Mortars are characterized by even shorter barrels and very high angles of fire, basically intended to make sure the round lands on the roof, in the trench, behind the walls of a fortification, etc. The U.S. M-120 120mm mortar fires HE rounds with muzzle velocities of 100 to 300 m/s.

Hope that helps.

 

[snrdg082102]

Evening Carlobrand,

Thanks for the numbers which gives me a clue on the velocity ranges that make a smooth bore hypervelocity.

Well, let's see:

My reference here says the maximum range of a projectile fired from a gun at 45 degrees is (v^2)/G. That's without air resistance, of course. Air resistance plays a big role and is going to be hard to factor 'cause the bigger guns are going up into thinner air. My math isn't up to that kind of calculation - I understand they generally use range tables or let a computer figure it out nowadays. Anyone with the necessary math skills can calculate from the ranges given in Striker.

So ... let's look at some modern examples. First off, muzzle velocity varies a chunk with the round. HE rounds are fired at lower velocities than APDS rounds from the same gun.

Muzzle velocity of an M-1's Rheinmetal 120mm is between 1600 and 1750 m/s depending on the specific round.

The 1950's era Ordnance QF 20 pounder, of the Centurion tank of that period had a 1400 m/s DS round.

The Soviet D10, mounted on 1950's era T-55 tanks, had a muzzle velocity of 1000 m/s.

A WW-II Sherman Tank's M3 75mm gun had a muzzle velocity of 619 m/s.

A WW-II T-34's 76mm gun had a muzzle velocity of between 600 and 700 m/s, depending on the round. Its APDS round hit 965 m/s.

So, as a ballpark, I'd think medium velocity is in the 600 m/s range, high velocity's in the 1000 m/s range, and hypervelocity's in the 1500+ m/s range. Roughly - which is about as good as it gets for these things.

Modern howitzers, like the US M-109, seem to fall into the 500-600 m/s range. The Soviets in WW-II had a 152mm with a 500 m/s muzzle velocity. Howitzers tend to have a shorter barrel and higher angle of fire than guns.

Mortars are characterized by even shorter barrels and very high angles of fire, basically intended to make sure the round lands on the roof, in the trench, behind the walls of a fortification, etc. The U.S. M-120 120mm mortar fires HE rounds with muzzle velocities of 100 to 300 m/s.

Hope that helps.

 

[nobby-w]

Well, let's see:

My reference here says the maximum range of a projectile fired from a gun at 45 degrees is (v^2)/G. That's without air resistance, of course. Air resistance plays a big role and is going to be hard to factor 'cause the bigger guns are going up into thinner air. My math isn't up to that kind of calculation -

...

It's quite complicated - ENIAC was originally developed to be used for precisely this calculation. IIRC it's some sort of horrendous PDE or some such that has to be solved numerically.