HEAP and KEAP small-arms

[Carlobrand]

Joe the Big Game Hunter lands on Planet X in his Safari ship. His plan: to bag the elusive snark. He looks over his array of arms - some of which would draw unfavorable attention from Imperial authorities if they knew he had them - but he has attorneys and money to deal with those inconveniences.

What should he take? The Assault Rocket Launcher was overkill - he wanted to bag a prize, not put fist-size holes in it. His LAG - same. His 13mm rifle was a bit shy for this - but he had those new rounds, with a superdense penetrator core, the ones he'd bought from a specialty manufacturer on Rhylanor. Yes, that felt right.
...

I'd like to discuss HEAP and KEAP small-arms. Canon weapons introduce some interesting concepts. There is, for example, the snub pistol and its 10 mm HEAP round. There is the 20mm LAG and its KEAP round that hits almost as hard as a 20mm high velocity cannon of similar tech.

Question: would you allow HEAP rounds - a la the 10mm snub pistol - for other large caliber weapons like the 13mm hunting rifle, 18mm shotgun or 20mm LAG, and if so how would you rate them? Would the round itself need to be underpowered - with shorter range - in order for the HEAP warhead to work (and would that be an advantage in the case of the LAG) or could it fire with normal power and range at TL-7+ (as in Striker)?

Question: would you allow tech level progression for the rounds of more mundane weapons like rifles, as with KEAP rounds, as more exotic materials became available for specialty rounds? Would you allow specialty DS rounds? Would you allow KEAP tech level progression for the LAG?

Question: would you allow a HEAP small-arm to benefit from the HEAP progression found in Striker and MegaTraveller?

Question: the smallest in-game rifle/ram grenade is the 4cm, but modern armies are experimenting with grenade launchers as small as 20mm and 25mm, perhaps also rifle grenades. Would you introduce such weapons, perhaps using the Striker rules to extrapolate their performance?

 

[BlackBat242]

OK, correct me if I'm wrong, but...
kinetic energy armor penetrator
Doesn't this actually say "solid bullet"?

No explosive, or the like... just a hunk of material depending on mass and velocity to punch through armor. Sounds distinctly low-tech to me.

 

[mike wightman]

The thing is the kinetic energy of the KEAP round can be higher than the explosive chemical energy of a HEAP round,

Most tanks today use a depleted uranium KEAP round to take out other tanks.

The US Navy is just about to complete the testing stage of an EM railgun that fires solid projectiles at such high velocity that explosive rounds are not needed.

 

[mike wightman]

Question: would you allow HEAP rounds - a la the 10mm snub pistol - for other large caliber weapons like the 13mm hunting rifle, 18mm shotgun or 20mm LAG, and if so how would you rate them? Would the round itself need to be underpowered - with shorter range - in order for the HEAP warhead to work (and would that be an advantage in the case of the LAG) or could it fire with normal power and range at TL-7+ (as in Striker)?

I have had !0mm full power "snub" pistols, carbines, rifles and machine guns IMTU. These all do pretty much what you suggest - use a standard cartridge to fire the small warhead, thus increasing the range.

Question: would you allow tech level progression for the rounds of more mundane weapons like rifles, as with KEAP rounds, as more exotic materials became available for specialty rounds? Would you allow specialty DS rounds? Would you allow KEAP tech level progression for the LAG?

I've never thought of it but its a really good suggestion.

So yes, IMTU these things are about to appear... off to play with Striker.

Question: would you allow a HEAP small-arm to benefit from the HEAP progression found in Striker and MegaTraveller?

Yes

Question: the smallest in-game rifle/ram grenade is the 4cm, but modern armies are experimenting with grenade launchers as small as 20mm and 25mm, perhaps also rifle grenades. Would you introduce such weapons, perhaps using the Striker rules to extrapolate their performance?

Again yes

 

[Carlobrand]

OK, correct me if I'm wrong, but...
kinetic energy armor penetrator
Doesn't this actually say "solid bullet"?

No explosive, or the like... just a hunk of material depending on mass and velocity to punch through armor. Sounds distinctly low-tech to me.

Well, no. The stock bullet is a shaped piece of lead or a copper-alloy compound with a lead core. It tends to deform when it hits flesh, which is what makes it hard on us fleshies. Unfortunately, it also deforms rather easily on impact with armor, which means some of the energy that would otherwise go toward breaking armor is instead going toward deforming the bullet, and the deformation on contact means the energy is spread along a slightly wider area of armor.

A modern KEAP round is something dense and hard, and usually narrow, so the round itself absorbs as little of the energy at impact as possible and transmits as much of that energy as possible to the armor it's hitting - in as small a spot as possible. It tends to be in a sabot - a light outer piece that surrounds it in the barrel to make it fit the barrel but that falls away after firing, leaving a dense rod to fly with less air resistance. The denser the rod, and the more effective it is at resisting deformation, the more energy gets transmitted to the armor, allowing the rod to either punch through or to make the armor shed lethal high-speed fragments of itself into the compartment on the other side (spalling).

There are armor piercing bullets - the common method is to use tungsten or some other really hard metal in place of the lead so the core of the bullet doesn't deform on impact and transmits more energy to the armor it hits. Makes it more likely to penetrate armor, but a possible disadvantage is that if it resists deformation, it may pass right through a fleshie target and take some of its energy with it, delivering less energy to a fleshie target and therefore being less lethal.

 

[Icosahedron]

Question: would you allow HEAP rounds - a la the 10mm snub pistol - for other large caliber weapons like the 13mm hunting rifle, 18mm shotgun or 20mm LAG, and if so how would you rate them? Would the round itself need to be underpowered - with shorter range - in order for the HEAP warhead to work (and would that be an advantage in the case of the LAG) or could it fire with normal power and range at TL-7+ (as in Striker)?

Yes, I have heap rounds in sizes from 10mm up, using a combination of Striker and FFS. FFS tends to rate the ammo as you go - I just have to tweak the design to fit the LBBs etc.

Question: would you allow tech level progression for the rounds of more mundane weapons like rifles, as with KEAP rounds, as more exotic materials became available for specialty rounds? Would you allow specialty DS rounds? Would you allow KEAP tech level progression for the LAG?

TL progression is ok, but I tend to limit my gaming to certain TLs in order to keep a lid on my prep work. Just a meta-game thing.

Question: would you allow a HEAP small-arm to benefit from the HEAP progression found in Striker and MegaTraveller?

Likewise.

Question: the smallest in-game rifle/ram grenade is the 4cm, but modern armies are experimenting with grenade launchers as small as 20mm and 25mm, perhaps also rifle grenades. Would you introduce such weapons, perhaps using the Striker rules to extrapolate their performance?

I have produced specialist 20mm shotgun ammo, and even some specialist 10mm snub ammo. (My shotguns are standardised at 20mm. I also have just a few standard weapon calibres - 4mm gauss, 5.5mm, 6mm accelerator, 7mm, 9mm, 10mm, 20mm. Anything else, you don't get it off the shelf. Again, it reduces my prep work.

 

[BlackBat242]

Well, no. The stock bullet is a shaped piece of lead or a copper-alloy compound with a lead core. It tends to deform when it hits flesh, which is what makes it hard on us fleshies. Unfortunately, it also deforms rather easily on impact with armor, which means some of the energy that would otherwise go toward breaking armor is instead going toward deforming the bullet, and the deformation on contact means the energy is spread along a slightly wider area of armor.

A modern KEAP round is something dense and hard, and usually narrow, so the round itself absorbs as little of the energy at impact as possible and transmits as much of that energy as possible to the armor it's hitting - in as small a spot as possible. It tends to be in a sabot - a light outer piece that surrounds it in the barrel to make it fit the barrel but that falls away after firing, leaving a dense rod to fly with less air resistance. The denser the rod, and the more effective it is at resisting deformation, the more energy gets transmitted to the armor, allowing the rod to either punch through or to make the armor shed lethal high-speed fragments of itself into the compartment on the other side (spalling).

There are armor piercing bullets - the common method is to use tungsten or some other really hard metal in place of the lead so the core of the bullet doesn't deform on impact and transmits more energy to the armor it hits. Makes it more likely to penetrate armor, but a possible disadvantage is that if it resists deformation, it may pass right through a fleshie target and take some of its energy with it, delivering less energy to a fleshie target and therefore being less lethal.

So you are talking WW2-era steel bullets... my father has a box of 30-06 Spr. "AP" bullets from his time in the Army... they are simply solid steel.

If you are talking about discarding sabot rounds, then the acronym should be Armour-piercing discarding sabot (APDS), DSKEAP, or KEAPDS... not just KEAP, as that indicates a non-saboted round.

Note that the "modern KEAP round" fired by the M1 Abrams is designated APFSDS (armour-piercing fin-stabilized discarding sabot).

 

[Carlobrand]

So you are talking WW2-era steel bullets... my father has a box of 30-06 Spr. "AP" bullets from his time in the Army... they are simply solid steel.

If you are talking about discarding sabot rounds, then the acronym should be Armour-piercing discarding sabot (APDS), DSKEAP, or KEAPDS... not just KEAP, as that indicates a non-saboted round.

Note that the "modern KEAP round" fired by the M1 Abrams is designated APFSDS (armour-piercing fin-stabilized discarding sabot).

Umm, I'm not really intending to debate terminology here. The game calls them KEAP, I'll call them KEAP for game purposes. Question on the floor is, "how do you prefer to apply the game rules," not, "how badly do the game rules mismanage its representation of real-world items."

As to steel bullets - maybe. I'm no expert on bullets, least of all WW-II varieties. There was a shortage of copper during the war - no great surprise - and steel was used at times to replace copper in both casings and jackets. It was also used for pennies. I don't know of a solid steel rifle or pistol bullet, and my reading suggests that such a bullet would be very hard on the gun firing it, quickly eroding the grooves that impart the bullet's spin. However, as I said I'm no expert. I'm curious as to whether your father's rounds have a ring of some softer metal to deal with that groove business.

On a more modern note, the teflon-coated hardened brass bullets sometimes called "cop-killers" are an example of an armor-piercing bullet (interesting side story there - the teflon isn't intended to aid penetration but to help protect the aforementioned grooves from the hardened bullet and to provide a bit of grip when the round hits windows and such). I aso found mention online of a 7.62mm M948 SLAP, a saboted tungsten carbide rifle bullet.

 

[Dragoner]

AP bullets, copper jacketed steel, just an fyi. I once bought a bunch of 7.62x39 in a can and a Russian read it and said "look AP!" I used a magnet and sure enough.

 

[sabredog]

I used to use Striker for CT combat but eventually switched back to the regular LBB1 system because too many PC’s were dying from the lack of flexibility in the Striker system when it comes to applying damage to a player character. It’s realistic, which I like, but players hate since its unmerciful.

Be that as it may I made some modifications to the LBB1 system to take into account some of the things I liked best about Striker. So I have a by-Tech level modifier chart for combat armor and battle dress like you get with Striker. That fixed the “King of the Battlefield” effect of the gauss rifle from LBB4 for example, but made the need for HEAP and KEAP(ER) rounds for heavy caliber slug-throwers more important.

So for your questions: yes, I would allow and do have HEAP rounds for high caliber CPR small arms. For HEAP the round doesn’t need to be underpowered. The round is just a round-nosed HE slug with the small stand-off fusing rod like on a tank HEAP round under the frangible round nose. The velocities of the round might be smaller, realistically, than those of a standard slug but not so much as is affects the ranges in personal combat enough that I think changes need to be made. You're talking about ranges in personal, not tank vs. tank combat made at kilometers.

In fact, a squash-head HESH type might be the best bet for what you are looking for since it wouldn't be deflected as easily at higher velocities. It just "splats" against the armor and detonates without really penetrating the aromr - just transferring the energy through it. It would have lower DM's than HEAP for penetration, but the damage might be the same since it'd be like a shotgun round exploding in your suit from the spalling. And if from an automatic grenade launcher or high caliber auto-LAG (like 20mm and seriously damped for recoil) it would be pretty nasty.

KEAP and KEAPER are different, and more accurate at longer ranges than standard rounds.

The biggest difference is just that HEAP has lower armor DM’s but does more damage than KEAP, and KEAP had higher armor DM’s relative to type and range, but does less damage. Standard ammo is just below HEAP in armor DM, but a little better at long range DM’s.

As for all the materials technologies …yes,, yes, yes…mainly it just means the weapon is lighter, costs more, and is more reliable. But realistically that’s all the effect would be for the game unless you want weapon charts that look like the spreadsheets for a Fortune 500 company to cover all the variables.

Grenades….they all do the pretty much the same damage and DM’s, but get smaller at higher TL’s. So at TL-10 your 40mm RAM grenade is now 30mm, at 12 it’s 20, and at TL-15 it’s 15mm. The 20mm and 15mm versions do 6D6 instead of 8D6 for the HEAP versions (the HE is the same), but then, at that TL they are used more for area effect in autofire weapons than as something to breach personal heavy armor like combat – that’s what laser rifles and P/FGMP’s are for. As they get smaller, it becomes more practical to use them as an area effect personal weapon – like the Assault Rocket Launcher does.

I also have these for early kinetic kill weapons if you want to dabble with early TL railguns:
http://freelancetraveller.com/features/consgoods/guns/earlygauss.html

They help bridge the gap between what CPR slug-throwers can realistically do as a small arm and the TL-12 gauss rifles as the peak for slug-thrower technology. After that energy weapons and lasers are a better option.

 

[BlackBat242]

Well, I don't remember if there was any sheathing near the casing, but the bullets in the 30-06 rounds were certainly steel (very hard, silver-grey with tiny rust spots, and magnetic)... and the box stated they were armor-piercing rounds.

 

[Enoki]

Given the technology available in Traveller I could see a higher tech version of something around .30 to .50 cal in a KEAP round that would punch several inches of steel plate.

One way would be the gun is smoothbore using some alternate method to stabilize the round in flight for accuracy. The round itself is a sabot round with the actual penetrator looking alot like a modern KEAP 'dart' fired by larger cannon. The difference is that the penetrator is made from a highly densified material so it weighs say 350 grains (a modern .30 bullet weighs 180 grains and is full sized) to maybe 1000 grains for a .50 round.

This round being a bit bigger in diameter than a toothpick and fired at say a muzzle velocity of 5000 fps or more would drill through armor at short range several inches thick.

HEAT and HEAP are more problematic. They rely on chemical energy to which there is a scientific limit. So, their size and weight of explosive are going to determine their effectiveness.

Now, if you had some some vicious nasty chemical that when splashed on steel plate etc., would eat through it in a major way compared to the amount that might work assuming it could be safely contained somehow.....

 

[Carlobrand]

Apparently there's something called a "frag-12", a 12-gauge shotgun round that fires a small fin-stabilized 19mm grenade.

http://www.defrev.com/1_31_2004/FRAG 12.pdf

Link says there's a HEAP version that penetrates a half-inch of steel armor, so equivalent to a Striker penetration of 5. There's an HE and an HE fragmenting anti-personnel round as well.

It is certainly possible to make smaller shaped-charge penetrators, but likely not worthwhile - you'd get more penetration from a regular bullet. Might have some industrial application.

Striker gives us a 30mm CPR HEAP with a TL6 penetration of 1 and a TL7-8 penetration of 9 (assuming a howitzer). MT skips the odd numbers but its 40mm HEAP (howitzer) lines up with the Striker 40, so likely the 30 would as well. The 10mm snubbie's HEAP has a penetration of 6 - unrealistic, but it's in the game. So, I'd think a shotgun HEAP at TL8 would probably have a penetration of 7 and be designed more or less like the FRAG-12. Maximum range of the Frag-12 is 200 meters, so for Striker purposes I'd use the Striker shotgun ranges and add an extreme range of 200 meters. Not quite the punch of the LAG KEAP, and a good deal shorter-ranged, but not as much kick, a pretty effective combat weapon.

HEAP does TL increase at TL9, 11, 13, but the 19mm and the 10mm are very small rounds. We've already said the 10mm snubbie is unrealistic - might be worthwhile to rein it in while doing the TL boosts. I'm thinking take the shotgun round to 10 at TL9, 12 at TL11, and 15 at TL13, blends it into what Striker suggests for a 20mm HEAP. As for the snubbie: 8 at TL9, 9 at TL11, and 10 at TL13?

HE is easier. Striker/MT 20mm at TL5 is a penetration of 1, 2 at TL7, 3 at TL9, and so forth. Snubbie's a 1 at TL8. We can just lift the Striker 20mm penetration and progression for the shotgun HE round: at TL8 it earns a small (10mm) danger space, at TL 9 enetration is 3, .

Now, acquiring the ammunition - that's a neat trick. We're talking a world of both appropriately high tech level and low law level, unless you're a merc company with the necessary legal papers and authorizations to buy the things. Might be an export trade going to low law worlds of lower tech, but it'd cost a good chunk more.

 

[Timerover51]

Carlobrand, are you still interested in this or not.

One way would be the gun is smoothbore using some alternate method to stabilize the round in flight for accuracy. The round itself is a sabot round with the actual penetrator looking alot like a modern KEAP 'dart' fired by larger cannon. The difference is that the penetrator is made from a highly densified material so it weighs say 350 grains (a modern .30 bullet weighs 180 grains and is full sized) to maybe 1000 grains for a .50 round.

One word: Recoil (see .600 Nitro Express recoil with 900 grain slug at 1800 feet per second)

Second concept: Bore erosion from powder charge and sabot. The Russian 115mm smoothbore tank gun had a barrel life expectancy of 200 rounds (the Russians did not think that the tank would last that long in combat). The NATO 105mm tank gun has a life expectancy of 400 rounds. After which, it needs to be replaced. Then there is "tube droop" if fired rapidly.

Small grenades: The Germans used a 30mm HEAT rifle grenade in WW2 and also a 30mm frag rifle grenade. Both were ineffective. The 40mm grenade launcher round uses a pre-fragmented steel coil, with the smallest fragment possible that will produce a casualty, and has an effective radius of 5 meters. Beyond 10 meters, the fragments are useless.

 

[Carlobrand]

Carlobrand, are you still interested in this or not.

Well, yes.

One word: Recoil (see .600 Nitro Express recoil with 900 grain slug at 1800 feet per second).

See also LAG.

Second concept: Bore erosion from powder charge and sabot. The Russian 115mm smoothbore tank gun had a barrel life expectancy of 200 rounds.

A real-world problem which Traveller ignores. Might be interesting to implement in a role-playing context, but probably not worth it for wargaming unless you're applying some sort of maintenance rules.

Small grenades: The Germans used a 30mm HEAT rifle grenade in WW2 and also a 30mm frag rifle grenade. Both were ineffective. The 40mm grenade launcher round uses a pre-fragmented steel coil, with the smallest fragment possible that will produce a casualty, and has an effective radius of 5 meters. Beyond 10 meters, the fragments are useless.

Indeed, the Traveller version for the TL 6-7 40mm has no burst size, works off special rules. Question is, would you apply the tech level modifiers used for CPR rounds to small arms KEAP or HEAP rounds like the LAG and Snub? The 30mm was ineffective in WW II, but they're experimenting with 25mm grenades nowadays, presumably with better explosives and a better understanding of how fragmentation works.

 

[Timerover51]

When you look at the data on the LAG, it is basically a slightly higher-velocity shotgun. A 30 gram projectile at 500 meters per second converts into a 460 grain slug at 1640 feet per second. A Brenneke 12 gauge shotgun slug weighs 490 grains at about 1320 feet per second.

The HE round is ridiculous at that weight, considering you would have to include a fuze and explosive in the slightly over 1 ounce projectile. Unless it hit you and penetrated, it is non-effective. Remember, this is supposed to be a Tech Level 8 weapon, i.e. real world now. The trajectory should look like a rainbow.

With flechettes, it is essentially a rifled shotgun, with an effective range of maybe 100 to 150 yards, assuming that the flechettes will stabilize at that low velocity. Double 00 buckshot would work just a well.

With those 20/9mm discarding sabot rounds, you probably would duplicate the penetration of your standard 7.62mm AP rounds, with the problem of what happens to the sabot when the round leaves the barrel. Any troops near the muzzle that are on your side are not going to be happy with you when fragments of the sabot hit them in the back.

Hard to beat it as a piece of useless ironmongery. For a real 20mm weapon, look up the 20mm Solothurn AT rifle or the WW2 Japanese 20mm AT rifle. John George in Shots Fired in Anger thought that the Jap 20mm made a nice shark hunting gun.

 

[Dragoner]

IMO we are TL 7 and IMTU this is the LAG, a Steyr AMR:

http://en.wikipedia.org/wiki/Steyr_IWS_2000

 

[mike wightman]

I take issue with the TL8 is real world now bit, looking at the TL charts we are firmly in the TL7 category in everything apart from computer technology.
No laser carbines, no fusion power plants, no air/rafts.

I do agree, however, that the LAG as presented in Traveller is totally underpowered. The various .5 calibre and more impressive 20mm canon rounds fired by the sniper/antimaterial rifles of today are far superior.

 

[Carlobrand]

When you look at the data on the LAG, it is basically a slightly higher-velocity shotgun. A 30 gram projectile at 500 meters per second converts into a 460 grain slug at 1640 feet per second. A Brenneke 12 gauge shotgun slug weighs 490 grains at about 1320 feet per second. ...

Agreed. It's definitely not what was advertised in the sales manual. I expect something with a kick more like a good ol' fashioned .577 Nitro and more punch than what the book gives it. Lines up as a wee bit more powerful than a 20mm low velocity CPR - which fortunately makes it handy for revising. Conveniently, the round weight's just a wee bit more than the 20mm CPR. I'd kick up the muzzle velocity and slug weight a bit, call it equivalent to a 20mm medium-velocity, give it a penetration of 12. Now there's a reason to endure some recoil, takes on combat armor up til TL 14.

One advantage of an HE round is it kicks up the damage - wounds become one level more severe, serious wounds become death. Not useful on the battlefield - combat armor's pretty common by that point, and unarmored soldiers are quite nicely vulnerable to more traditional weapons. However, I can see a big game application, as long as you don't ruin your trophy by hitting it in the head.

 

[Icosahedron]

IMO we are TL 7 and IMTU this is the LAG, a Steyr AMR:

http://en.wikipedia.org/wiki/Steyr_IWS_2000

A modern-day crossbow.

You have another vote for today = TL7.