120mm Ammunition

I was a Tank Commander

I recently did a post clearing up some questions people had about Tanks and Armored Warfare. A lot of people wanted to know about gunnery, so here we are.

First, a Lesson on Parallax

If you look at the M1-Series tank, you may notice something. The main gun (cannon) and the Gunner's Primary Sights (rectangular box just above the cannon in the picture) don't point in the same direction. This causes something called parallax, where what the eye sees and where the cannon is pointed don't add up.

To compensate for this, the tank uses an incredibly complex computer, and a little device called the MRS.

What is an MRS?

The Muzzle Reference Sensor is a small tube that is used to calibrate where the sights look compared to the cannon. As a tank crew, we can fight with our without our computers (think the movie Fury).

The MRS allows us to quickly calibrate against parallax, shoot straight, and destroy the enemy faster than they can find us.

Oh, and yes. That is a radioactive symbol you see there. It's literally the least dangerous thing about working in a tank.

Bore Evacuators

Watch the gif. Notice something? After the initial explosion (blast envelope), you can see a secondary puff of white gas. That is from the Bore Evacuator, the little hump in the middle of the cannon.

Bore Evacuators help prevent flareback, or gasses pumping back into the turret after a round is fired. It's not deadly, but it can be startling and sometimes dangerous.

Essentially, the initial explosion carries the majority of gas out of the cannon, but a little is trapped in the evacuator. Then, the vacuum effect of the blast pulls that gas out through the cannon. This in turn pulls any leftover debris from the cartridge out of the tube.

The Almighty SABOT

The APFSDS-T (Armor Piercing Fin-Stabilized Discarded Sabot-Tracer) is the all-purpose anti-tank round. It is often called the "Silver Bullet," because it will absolutely ruin the enemy's day.

What is a SABOT?

The "SABOT" refers to the petal around the actual projectile, which is a Depleted Uranium (DU) spike. The petals keep the round snug in the cannon so a proper ballistic solution can be made.

How does that work?

The petals fly off as soon as the round leaves the cannon, letting the lawn dart fly off in search of new friends. This guy flights VERY straight and level, and can hit targets well over 2 miles away.

What good is a lawn dart?

In a few words? Kinetic energy.

The SABOT travels at an insane speed (the newer darts break the sound barrier a few times over). That kind of impact tends to get physics all pissed off.

But is it effective against vehicles?

The kinetic energy generates so much heat, it melts the skin of the vehicle and uses that molten metal as shrapnel. A SABOT can kill just about any target.

Effective?

During the Thunder Run, when 1st Armor drove to Baghdad during Gulf War 2, Iraqi armor hid behind berms of sand. Iraq is very flat in large areas, and these berms stood out like sore thumbs. An enterprising tank commander did a "recon by fire," (shoot at something and see what happens), and a second later the turret of a hidden T-72 flew into the air.

The SABOT went through the sand berm, through the tank, blew up the ammo rack, and ripped the top off the enemy tank.

Feel the HEAT

High Explosive Anti-Tank rounds. These are the grandaddies of the ammunition ready rack. Simple (sort of), and made to work every time, these are no longer the primary armor defeating round. Instead, they are used on trucks, armored transports, buildings, and masses up groups of people.

How do they work?

Unlike the SABOT, these are explosive rounds. The "head" of the round is the pressure-sensitive warhead. When it comes in contact with its target, it activates a simple-but-effective method of destruction.

The power of Copper

A small copper plug is super heated on impact. Little known fact: melted copper can melt through a ton of things, and very quickly. The melted copper plug burns through armor, leaving a hole.

Then an explosion fills that hole.

And against a tank?

Yes, but only the older models. T-90's need a little more love than a HEAT can provide.

The Canister Round

The Canister, or CAN round, is a shotgun shell for tanks. It is used to disrupt enemy troop movement. At 300-500m, it is...very effective.

Zombies be gone

It can be used against soft-skinned vehicles, but mostly it is for use against troops on the ground. So zombies. This is how we defeat zombies.

More Questions?

Yes, there are more ammunition types that I am leaving off, mostly because I don't know if they are unclassified yet and I'm not taking that risk.

If you do have more questions, ask me anything.