HEAT rounds and Sabot rounds just aren't useful against civilians or soft targets. They're a weapon for dislodging highly armored enemies: like bunkers, tanks and the like.
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The weapons that are useful against soft targets are pistols, machine guns, rifles, and the like. And they're already being used in crimes and other such situations.
There's no point shooting 120mm tank sabot rounds at people, because a 9mm pistol will effectively kill at much cheaper prices. There's pretty much nothing to fear from the more sophisticated weapons. A singular 120mm tank round weighs nearly 40 lbs.
In contrast, you can carry something like 1000+ rounds of 9mm ammunition in the same 40lbs weight. The weapons used on the battlefield (ex: missiles, HEAT rounds, rockets, etc. etc.) simply aren't useful in soft / civilian settings.
But that still has all the problems associated with why M1 Abrams are suboptimal for infantry.
1. Very slow rate of fire -- It takes time to load the weapon.
2. Low number of shells -- an M1 Abrams only can carry 40ish shots.
3. Extreme heavy weight / armor is redundant -- 70-tons means really big engines, really big engines uses a lot of fuel.
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I'd say the "heavy vehicle" that is actually designed for infantry are the M2 Bradley IFV. Less than 30 tons, a smaller 25mm chain gun with 900-rounds, armor still too thick for small-arms fire (but not redundantly / absurdly thick like the M1 Abrams).
The 25mm cannon is still capable of firing those "anti-trench burst rounds" that started this thread, and a faster rate of fire would be more useful than a bigger, slower 120mm boom.
Things like the M1 Abrams exist to kill things like the M2 Bradley. Sure, the M1 Abrams has some tricks (mainly the 50-cal secondary gun) to deal with infantry, but a lot of its features are straight up redundant if there's no enemy armor around.
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A lot of military weapons, maybe most of them, exist to beat the strategies that beat lower level tactics. Ex: F22 is designed to kill airplanes, but cannot serve as a close-air support fighter very well.
A civilian might have to worry about a Predator Drone (seemingly the main weapon we use to kill targets from the sky). But civilians don't have to worry about F22.
HEAT rounds and Sabot rounds just aren't useful against civilians or soft targets. They're a weapon for dislodging highly armored enemies: like bunkers, tanks and the like.
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The weapons that are useful against soft targets are pistols, machine guns, rifles, and the like. And they're already being used in crimes and other such situations.
There's no point shooting 120mm tank sabot rounds at people, because a 9mm pistol will effectively kill at much cheaper prices. There's pretty much nothing to fear from the more sophisticated weapons. A singular 120mm tank round weighs nearly 40 lbs.
In contrast, you can carry something like 1000+ rounds of 9mm ammunition in the same 40lbs weight. The weapons used on the battlefield (ex: missiles, HEAT rounds, rockets, etc. etc.) simply aren't useful in soft / civilian settings.