What If The Sniper In Saving Private Ryan Fired A Round Down The Barrel Of The King Tiger?

While a sniper does not conventionally engage a tank in this manner; should the proposed situation occur, and the sniper’s bullet went straight down the center of the 120mm barrel and struck the projectile on the tip the outcome would have several variations depending on which round was battle-carried:

Depleted Uranium SABOT round: The part that would be struck is solid metal and has no High Explosive in it whatsoever. It is a kinetic energy round designed to take out other tanks. Nothing would happen whatsoever to the tank, not even barrel damage from fragment ricochets because the entire round is housed within the solid steel breech, which is designed to absorb the blast of the propellant when the round is fired normally. The projectile may have its flight characteristics altered.

MPAT round: The part that would be struck is a manually adjustable proximity fuse that enables the loader to set the projectile to a conventional High Explosive contact munition, or to an air burst mode designed to take out anti-tank helicopters by concussive blast when in proximity to a target (also works on walls to make big round holes instead of over-penetrating into another room or through the building entirely!) While this round is H.E., again, the piece that was struck is the fuse/sensor and so no catastrophic failure of the round would take place, and no damage to the barrel because the round is entirely housed within the breech, which is designed to absorb the blast of ignited propellant.

High Explosive Anti-Tank round: The HEAT round would possibly be the only round that could pose a threat to the tank and its crew. The projectile is a chemical energy shape charge. Imagine a coffee can with a piece of dowel rod sticking out of one end. That rod is a plunger that, when depressed by contact with the target, creates a chemical reaction within the canister portion of the projectile and a molten jet of high explosive and either a metal or a White Phosphorous-type caustic melting agent is shot into the target, incinerating everything in its path. This, coupled with the H.E. explosion on impact make this round exceptionally effective against different classes of targets, including tanks. My concern would be that if a sniper’s bullet struck the plunger, it would possibly detonate the business end of the projectile inside the breech, which could possibly have a catastrophic failure.

I have never heard of this happening, and don’t know if the projectile would be detonated inside or how the breech would handle it. That, however, in my mind, is the only questionable scenario.

Junior Member

Registered: 05-07-09

That one bullet could fell a tank seems improbable. I seriously doubt a sniper of any caliber would risk giving away their position to take this kind of shot. I also doubt highly that the Army would give the Mythbusters a tank to try and destroy.

Senior Member

Registered: 02-17-08

A couple points of clarification to usmarinestanker’s post.

All US chemical energy warhead tank cannon rounds have internal safety mechanisms which prevent arming of the fuze assemblies prior to experiencing the acceleration forces of firing. In other words, if a sniper hits the stand-off spike/sensor probe/nose cone before firing, absolutely nothing will happen as the fuze activation circuit at that point is dead. This arming function can be an extremely sohpisticated dual mode mechanism, depending on the round.

In addition, all are base-detonating, which means there’s no chance a sinper’s bullet will penetrate all the way through the warhead and somehow detonate the initiator by impact.

As for sensor probes, keep in mind that rounds such as the M830 don’t require a strike on the end of the stand-off spike/sensor probe. These also have a shoulder activation circuit which permits graze detonation. (But again, the round has to be fired, first.)

As for the MPAT (the M830A1 HEAT-MP-T), the nose cone does not contin the entire fuze. Only the Front Impact Sensor Switch and Proximity Switch are located there. The M774 electronic Base Element and M69 Electric Detonator are located at the base of the warhead.

Need to correct errors in that shaped charge description.
1) The stand-off spike/sensor probe is *not* a plunger. Instead, when the tip is crushed, it closes a circuit which activates the base-detonating fuze. The spike is necessary to give the shaped charge sufficient stand-off for the jet to form before striking the armor
2) Not sure why you differentiate between how the MPAT and HEAT rounds work. The M908 HE-OR-T, M830A1 HEAT-MP-T (MPAT) and M830 HEAT-MP-T are all HEAT type warheads.
3) Not sure what you mean when you state that for HEAT rounds “a chemical reaction occurs within the cannister portion of the warhead.” You mention this as if this is different for HEAT rounds as opposed to MPAT rounds. But as noted above, both HEAT-MP-T versions and the HE-OR rounds are, of course all chemical energy warheads. For the yonkers out there, that “chemical reaction” is a detonation of high explosives which create the shaped charge effect.
4) “a molten jet of high explosive and either a metal or a White Phosphorous-type caustic melting agent is shot into the target”
This is completely wrong. The penetrating agent consists of a molten jet and a slower moving slug of metal formed from the cone lining material. The unclass description for US shaped warhead liners is a copper cone with a wave shaper (not further identified). There is no high explosive material being shot forward. There is no WP-type caustic melting agent involved.

Your description of what would happen with the the M829 series of APFSDS-T rounds was OK, though.

Junior Member

Registered: 05-07-09

@ binthere:

Thanks for making some clarifications on mechanics of the rounds and how they detonate. Even as a crewman we never got into extreme detail as to the interior makeup of rounds, such as the projectiles being “base detonating” as you state. It certainly makes sense as an extra safety measure. We knew that when they hit the target, it went away, and that was good enough!

Although it sounds like you’re quoting directly from a MilSpec Manual, (link for citations please) I would like to make several clarifications myself.

1.)I differentiate between HEAT and MPAT because, though they both contain high-explosives and can be used as anti-tank weapons, they are physically two separate rounds in shape, appearance, weight, and capabilities (added air burst mode vs only contact detonation). Because they function differently and because they are separate types of rounds, I included them in the original list because there is a chance that the sniper could shoot either one.

2.) I described the chemical energy process for HEAT rounds separately from MPAT rounds because, as I was taught at Ft. Knox, they function differently. Whereas the SABOT round simply penetrates like a regular bullet, we were taught that the HEAT round sends the shaped charge into the target (via the chemical reaction) to melt and incinerate the armor/crew, and the MPAT round simply explodes, like an artillery shell.

The reasoning behind this was that for “air burst” mode, it would be a waste of the same shape charge found in a standard HEAT round to be directed at potentially nothing if the MPAT round exploded mid-air because the proximity sensor was tripped. It was more cost-effective to simply send that explosion in all directions to ensure that the helicopter was taken out. This is also partly the reason that MPATs are not used as direct fire weapons against tanks unless absolutely necessary, because that “artillery-like” explosion, while still as powerful as any standard HE round of the same size, isn’t directed like a HEAT / SABOT round.

3.) By your own posting of the unclassified description, my description of “high explosive and *either* a *metal* *or* a WP-type….” was correct.

The round is called HEAT, which by definition involves “high explosive” (which must be detonated in the direction of penetration *[forward]* in order to send the “metal” which I described. That metal fits perfectly with the copper lining (which is a molten jet)/ slower moving slug of metal you cited from the Gov’t. I do admit that per the information you provided, there is no WP involved, my mistake.

All in all, though, my description of what happens when a HEAT round pops a turret off a tank and makes the crew crispy critters wasn’t nearly as inaccurate as it was claimed to be.

Again, your insight into the mechanics of the rounds at the beginning of your post was very insightful. If you have docs, I’d love to be able to read them.

Senior Member

Registered: 02-17-08

usmarinestanker,

A Milspec Manual? By that do you mean the Tomes of Military TRUTH. I don’t quote from them. I LIVE by them. Well, at least I did before I got old, cranky and retired.

Some of the best references for military ammo, as you know, are the Army Ammunition Data Sheets. In this case we’re talking TM 43-0001028, ‘Army Ammunition Data Sheets for Artillery Ammunition Guns, Howitzers, Mortars . . . ‘ and, well the title goes on forever. Pull out your copy or,here’s a link. Look to page 2-117 (or page 155 using the slider) for info on the M830A1.

Not to be a smart alec, but I have to point out that the M830A1′s official nomenclature is HEAT-MT-T, where the HEAT part means – wait for it – a shaped charge warhead. Or, that the term MPAT does stand for “Multipurpose AntiTank.” So it should be obvious we’re talking a HEAT round for antitank use (among others). While it may look different than the M830 and has a different fuze, they *are both* HEAT/shaped charge warheads.

The M830A1 is a dual purpose HEAT round, in common with a number of other military munitions. Remember the M433 HEDP (High Explosive Dual Purpose) round for the M203 grenade launcher? Two inches of armor penetration (from the shaped charge) plus a 5 meter kill radius from fragmentation? Same thing for the 120mm M830A1; it’s a shaped charge/HEAT warhead with blast and fragmentation effects. This shouldn’t be news to a tanker. Even the classic M830 HEAT round was designed to provide secondary anti-personnel fragmentation effects. They simply adapted this existing feature for use in an air defense role. (Well, that’s over-simplifying a weeeee bit.)

Here’s the official description of the M830A1 HEAT-MP-T (aka MPAT): “This cartridge is a high explosive antitank and air defense multipurpose, tactical service round with tracer.” Read on to the next page for descriptions of the shaped charge’s details. Or, check this link for a good cut-away of the round. You can plainly see the shaped charge. (You can trust this company’s info; they make the tank ammo.)

So the M830A1 is indeed a classic shaped charge HEAT round, with the addition of a sexy dual purpose warhead. And while you’d obviously prefer to send a silver bullet through an enemy tank, the M830A1 HEAT-MT-T does as good a job on armor as the classic M830 HEAT-MP-T which it replaces. Wait! Actually, it claims a 30% *better* performance against light armor.

Much of your text makes me suspect you’ve confused the M908 HE-OR-T for the M830A1 HEAT-MP-T – at least when talking about the form of detonation. Which isn’t difficult as – except for markings – they look nearly identical. The OR (obstacle reducing) round is designed to breach and destroy and is commonly thought to function as a plain old HE round. (Oddly enough, though, the M908 has *essentially* the same shaped-charge warhead as the M830A1 has, but with a different fuze. Which pretty much explains why they look alike.) So, like I said in my post, all three (M830, M830A1 and M908) are *all* HEAT type warheads – their terminal effects vary primarily due to fuzing.

On another note, while older tankers tend to associate sabot with KE rounds, both the M830A1 and M908 also use sabots, as their projectiles are actually sub-caliber.

As for the jet from a shaped charge “melting” through armor, that’s a common enough description, and one that is generally close enough for bored classroom explanations. I’ll skip the physics lecture (which I probably don’t understand myself) and just point out for general viewer information that it’s the huge, focused pressure wave created by impact of the hypersonic jet that deforms the armor, not a thermal transfer from the jet to the armor. Some folks don’t understand that.

In addition to being able to quote from manuals, I spent 26 years in the Army and am now a contractor working on the T&E end of the FCS program. I sure don’t know it all, but a lot of time I know where to find it – and I try to look there before posting. Can’t rely on pure memory like I once did.

Now, here’s a question for you. The M830A1 proved very popular among some tank units in urban combat in Iraq, even when they didn’t face tanks or helicopters. As a tanker, can you tell me why they proved popular against insurgents?

Junior Member

Registered: 05-07-09

Wow, your familiarity with the manuals (which I greatly appreciate you linking!) is awesome. Your technical expertise surpasses my “general knowledge” and I’m sensing that some of the things we were taught are either mistakes that were perpetually passed down as “fact” for one reason or another. I was only in the Corps for 4 years, and associated with tanks for just under 1 (thank you WP flare malfunction :[ ) This jarhead appreciates the schooling from an old salt.

RE: the MPAT round, we primarily set it to air burst mode to blow large 8′ diameter holes in walls of buildings / courtyards so that they wouldn’t collapse the structure or over penetrate into another room, or outright through the building. It wasn’t used as an anti-personnel round, per se, in my unit (A Co, 3rd Plt, 2nd Tank Bn, 2nd Mar Div (Sept 04 – Jan 05).