Latest posts for the thread "Assault Cannons... why?"

Assault Cannons... why?

Fire_for_effect — GMT

Heya

Befor me lies a terminator with a very sexy looking assault cannon. As much as I like the looks and the idea of said weapon, I am wondering: Does anyone actually use it? If so, why?
Technically, it doesn´t exell at anything. The heavy flamer is far superior when it comes to killing hordes of infantry and the Cyclone launcher is better at destroying vehicles, while still being good against hords and heavy infantry. I´ll go as far as to say that the ass. cannon is really only there for doing a bit of everything. But since it costs just as much as the cyclone launcher (and even more then the cyclone for Dark Angels), why would one go for the assault cannon except maybe for the fact that its cheaper to just use them, then to buy the bits for more cyclone launchers?

lg
FFE

Assault Cannons... why?

whembly — GMT

It depends on what role you're planning to use the termie... but... statistically speaking, an assualt cannon has an easier time penning a LandRaider than a Las Cannon.

Assault Cannons... why?

DarknessEternal — GMT

Fire_for_effect wrote:and the Cyclone launcher is better at destroying vehicles,

That actually is only true if the Assault Cannon is out of range. Under 24", it is superior at that.

Assault Cannons... why?

Sir_Prometheus — GMT

Yeah.....the statistical effects of rending and 4 shots versus a higher strength are one of those things that are a little hard to grasp intuitively. But it is, in fact, one of the best anti-tank weapons in the game, really only beat out by meltas within melta range (barely, and depending on target), railguns, and of course, psycannons.

It's also a damn fine anti-infantry weapons besides.

Re:Assault Cannons... why?

Zid — GMT

I tend to dislike AC's on anything that has trouble getting into range (or if its not twin linked lol)

Re:Assault Cannons... why?

ph34r — GMT

The Assault Cannon is actually pretty good at anti tank. It's short range is its biggest weakness, and the fact that it is not as good at killing marines in the open.

Re:Assault Cannons... why?

Jimsolo — GMT

Since I play Salamanders, I replace all my assault cannons with other things, but I see them fielded quite a bit. I think they are pretty dang good, but that's just my personal opinion.

Re:Assault Cannons... why?

SOFDC — GMT

Because they rip open transports at short range better than a cyclone. My terminators are usually vomiting forth from a land raider or landing in a pod, so the short range is much less of a detriment on average.

Re:Assault Cannons... why?

augustus5 — GMT

Zid wrote:I tend to dislike AC's on anything that has trouble getting into range (or if its not twin linked lol)

Teleporting terminators should have no trouble getting within 24 inches of the enemy. Even a very conservative deep strike should do the trick.

Generally, the cyclone is better received because of it's range, and the fact that it got better with this edition (extra shot), while the assault cannon got worse (d3 rend as opposed to d6). Also the cyclone doesn't replace the storm bolter, allowing the terminator to fire both weapons.

Assault Cannons... why?

Ultrafool — GMT

I love assault cannons, though Ive never used them on termies since I don't use them. But I run two baal preds with asscannons and they do work, anti horde paired with heavy bolters, inflict many wounds against heavy infantry, and amazing anti tank. 75 percent of all the games I've played, I was able to rend and destroy AV14 with asscannons

Re:Assault Cannons... why?

SOFDC — GMT

In Ye Olde times, I would run them on anything that had the option. AC land speeders. AC tactical terminators (Back then, this was WHY I ran tactical terminators.) LRCs, Etc. Etc. Then they nerfed the rending rule, and other things took primacy on the various platforms, but they still serve their role in armies that run them. (Space wolves go here, as do Deathwing every once in a while. Deathwing less so, because they give up TH/SS rather than simply bolting on the cyclone.)

Even now they certainly are not bad.

Assault Cannons... why?

PraetorDave — GMT

On terminators I think you are right. On other things? They are awesome. Land Speeders? While expensive, the LS can get into range quickly. Dreadnought? Dreads don't have a problem being in close range, thanks to the DCCW. Plus they are TL. Land Raiders (of the crusader and redeemer variety)? They are TL and pair very nicely with the other weapons on that puppy. Baal Preds? I don't play BA but they do seem awesome.

Assault Cannons... why?

ZacktheChaosChild — GMT

I would give my left nut to have Long Fangs in the Chaos codex.

I would give my other for Assault Cannons.

Assault Cannons... why?

Tyranids? Tyranids. — GMT

ZacktheChaosChild wrote:I would give my left nut to have Long Fangs in the Chaos codex.

I would give my other for Assault Cannons.

ROFL

Assault Cannons... why?

Sephyr — GMT

I just wish Obliterators could spawn Assault Cannons. It would be fluffy -and- give them a way to put out high-volume fire, which they currently lack. Plus, they actually HAVE the barrels on the model!

However, Ass. Cannons strike me as something that needs a bit of spamming to shine. Field a single one and you can go games without seeing it rend, but two or three and you should get at least one lucky carnage each game.

Assault Cannons... why?

bruno.sardine — GMT

Sir_Prometheus wrote:Yeah.....the statistical effects of rending and 4 shots versus a higher strength are one of those things that are a little hard to grasp intuitively. But it is, in fact, one of the best anti-tank weapons in the game...

I've tried to mathhammer this out and as soon as I start getting into the probabilities of rending, etc., I get twisted up. Is this correct?

Assuming everything hits, the lascannon is one shot at S9, so it has a 1/3 chance (represented by rolling a 5 or 6) to penetrate AV14. Clean cut and simple.

Still assuming everything hits, the assault cannon is four shots at S6 with a 1/6 of rending. Rending gives a 2/3 chance to add 2 or 3 AP, which all together, will penetrate AV14. All that gives you an overall 1/9 chance to penetrate with every shot, so 4/9 over a single turn, again assuming everything hits.

Then, going back to account for the shots you'll flat out miss... BS 4 gives you a 2/3 chance to hit. So the single lascannon then has a 2/9 (22.2%) chance to hit and penetrate, whereas the assault cannon has an 8/27 (29.6%) chance... 2/27 (7.4%) higher than the lascannon.

Twin-linked, though, opens up the gap even more. Twin-linked BS4 gives you an overall 8/9 (88.9%) chance to hit, since the 1/3 times you miss, you get another 2/3 chance to hit. A twin-linked lascannon, then, has the same chance to pen AV14 as the original assault cannon, 8/27 (29.6%). A twin-linked assault cannon, though, has a 32/81 (39.5%) chance to pen AV14.... 9.9% higher than even the twin-linked lascannon.

Of course, this totally ignores situational advantages, like cover or how fast the vehicle moved the previous turn.

Lesson learned, I should start shooting my assault cannons against vehicles. Thanks for the heads up!

Re:Assault Cannons... why?

Adam LongWalker — GMT

Before we go into the 'Math Hammer" stage of the game we should see what is the current major GT tournament playing styles in question for this year. There are reasons why the high placing players in the GT circuit use certain types of builds to play and people should start using that kind of information and break it down to your needs.

Then comes the kinds of playing styles in your region, for this year, and finally, your playing style.

Then decide if the weapon/model/unit combination works for you.

Jesus Guns have their purpose like any other tool in your army.

Jesus Guns is an old skool term for the Assualt Cannon as back in the previous editions when you see a model/vehicle with an Assault Cannon and in number, many would mutter that prophetic name

Would I use the Jesus Gun on a Termie? Absolutely if you want having your termies (via deep strike and/or setup) into mid range shooting in which the weapon excels.

Assault Cannons... why?

Justus — GMT

Where can we see the lists of high ranking GT players?

I'm not sure if I would get an assault cannon on a Terminator squad, it seems like a pricy platform for one. Dreadnoughts and Land Speeders seem like better choices to me (but what do I know?).

Assault Cannons... why?

MrEconomics — GMT

bruno.sardine wrote:
Sir_Prometheus wrote:Yeah.....the statistical effects of rending and 4 shots versus a higher strength are one of those things that are a little hard to grasp intuitively. But it is, in fact, one of the best anti-tank weapons in the game...

I've tried to mathhammer this out and as soon as I start getting into the probabilities of rending, etc., I get twisted up. Is this correct?

Assuming everything hits, the lascannon is one shot at S9, so it has a 1/3 chance (represented by rolling a 5 or 6) to penetrate AV14. Clean cut and simple.

Still assuming everything hits, the assault cannon is four shots at S6 with a 1/6 of rending. Rending gives a 2/3 chance to add 2 or 3 AP, which all together, will penetrate AV14. All that gives you an overall 1/9 chance to penetrate with every shot, so 4/9 over a single turn, again assuming everything hits.

Then, going back to account for the shots you'll flat out miss... BS 4 gives you a 2/3 chance to hit. So the single lascannon then has a 2/9 (22.2%) chance to hit and penetrate, whereas the assault cannon has an 8/27 (29.6%) chance... 2/27 (7.4%) higher than the lascannon.

Twin-linked, though, opens up the gap even more. Twin-linked BS4 gives you an overall 8/9 (88.9%) chance to hit, since the 1/3 times you miss, you get another 2/3 chance to hit. A twin-linked lascannon, then, has the same chance to pen AV14 as the original assault cannon, 8/27 (29.6%). A twin-linked assault cannon, though, has a 32/81 (39.5%) chance to pen AV14.... 9.9% higher than even the twin-linked lascannon.

Of course, this totally ignores situational advantages, like cover or how fast the vehicle moved the previous turn.

Lesson learned, I should start shooting my assault cannons against vehicles. Thanks for the heads up!

I'm afraid you have the math wrong for the Assault Cannon. Your Lascannon math is correct, if we're calculating the probability of damaging AV14, as opposed to penetrating AV14, which has a 1 in 6 probability per hit, as you have to roll a 6.

The rules for calculating probabilities boil down to two major things. First, if several events are mutually exclusive, that is, if at most one of them can occur, the probability of one of them occuring is the sum of their individual probabilities. Second, if two events are independent of one another (that is, the fact that one of them occured has no influence on the probability of the other occuring) the probability of both occuring is the product of their individual probabilities.

So, if a single Assault Cannon shot gives you a penetrating hit with probability p, the probability of getting a penetrating hit from all four shots is not 4p, because getting a penetrating hit from shot 1 does not prevent you from getting a penetrating hit from shot 2, etc.

The correct math for the Assault Cannon is this. First, you have a 1 in 12 chance of a hit damaging AV14. This is because you need to roll a 6 to rend, and then roll at least a 3 on the subsequent d3. Since a single shot has a 2 out of 3 probability of hitting, the overall probability that a single Assault Cannon shot damages AV14 is 2/3 * 1/12 = 1/18. The probability that you DON'T damage AV14 is then 17/18 ^ 4 = .7956. The probability that you do damage AV14 is then 1 - .7956 = .2044, or a little better than 20%. The Lascannon is thus slightly better according to this statistic. On the other hand, the probability of getting at least one penetrating hit out of an Assault Cannon is about 14%, while the Lascannon's probability is 11.1%. Twin-linked, the results are still comparable. The Lascannon has a higher probability of doing something, the Assault Cannon a higher probability of getting a pen.

A Melta weapon in Melta range still beats the crap out of both of them. A BS 4 Meltagun has a 48.1% chance of doing something to AV14, and a 38.9% chance of inflicting a penetrating hit. On top of that, it does more damage when you roll on the damage table.

All this considered, a vehicle is still the ideal target for an Assault Cannon, especially if you can shoot it at AV10 or AV11. Most infantry is either not valuable enough per model, or has a 3+ or better save. Even TL against T4 or less, you'll only do a little less than 3 wounds on average.

Re:Assault Cannons... why?

bruno.sardine — GMT

Thanks for the clarification, MrE. I knew I'd gotten it wrong somewhere, that sounded way too good to be true. Makes my Baal Preds seem a lot better now

Re:Assault Cannons... why?

Grey Templar — GMT

the Clyclone missile is superior in nearly everyway. the assault cannon only is better against AV13+, but that requires it to be in range and thats also the range bad of Melta.

the Flamer is only worth taking if you have Vulkan.

so, unless you are playing Salamanders, always take Clyclone missile launchers.

Re:Assault Cannons... why?

puma713 — GMT

Here you go:

puma713 wrote:Here's a little chart for you, from http://www.warseer.com/forums/showthread.php?p=4872047 :

Single Assault Cannon

AV10
4x(66.7%) chance to hit = 2.667 hits at BS4
2.667x(33.3%) chance to penetrate = 0.888 Penetrating Hits
0.888x(33.3%) chance to wreck or explode = 29.570% chance of destroying AV10

AV11
4x(66.7%) chance to hit = 2.667 hits at BS4
2.667x(16.7%) chance to penetrate = 0.444 Penetrating Hits
0.444x(33.3%) chance to wreck or explode = 14.785% chance of destroying AV11

AV12
4x(66.7%) chance to hit = 2.667 hits at BS4
2.667x(16.7%) chance to penetrate = 0.444 Penetrating Hits
0.444 x(33.3%) chance to wreck or explode = 14.785% chance of destroying AV12

AV13
4x(66.7%) chance to hit = 2.667 hits at BS4
2.667x(11.1%) chance to penetrate (16.7% to rend and 66.7% to roll a 3+) = 0.296 penetrating hits
0.296x(33.3%) chance to wreck or explode = 9.857% chance of destroying AV 13

AV14
4x(66.7%) chance to hit = 2.667 hits at BS4
2.667x(5.6%) chance to penetrate (16.7% to rend and 33.3% to roll a 5+) = 0.147 penetrating hits
0.147x(33.3%) chance to wreck or explode = 4.895% chance of destroying AV 14

Single Lascannon

AV10
1x(66.7%) chance to hit = 0.667 hits at BS4
0.667x(83.3%) chance to penetrate = 0.556 Penetrating Hits
0.556x(33.3%) chance to wreck or explode = 18.515% chance of destroying AV10

AV11
1x(66.7%) chance to hit = 0.667 hits at BS4
0.667x(66.7%) chance to penetrate = 0.445 Penetrating Hits
0.445x(33.3%) chance to wreck or explode = 14.819% chance of destroying AV11

AV12
1x(66.7%) chance to hit = 0.667 hits at BS4
0.667x(50.0%) chance to penetrate = 0.333 Penetrating Hits
0.333x(33.3%) chance to wreck or explode = 11.089% chance of destroying AV12

AV13
1x(66.7%) chance to hit = 0.667 hits at BS4
0.667x(33.3%) chance to penetrate = 0.222 Penetrating Hits
0.222x(33.3%) chance to wreck or explode = 7.393% chance of destroying AV 13

AV14
1x(66.7%) chance to hit = 0.667 hits at BS4
0.667x(16.7%) chance to penetrate = 0.111 Penetrating Hits
0.111x(33.3%) chance to wreck or explode = 3.696% chance of destroying AV 14

Twin Linked Assault Cannon

AV10
4x(88.9%) chance to hit = 3.556 hits at BS4
3.556x(33.3%) chance to penetrate = 1.184 Penetrating Hits
1.184x(33.3%) chance to wreck or explode = 39.077% chance of destroying AV10

AV11
4x(88.9%) chance to hit = 3.556 hits at BS4
3.556x (16.7%) chance to penetrate = 0.594 Penetrating Hits
0.594x(33.3%) chance to wreck or explode = 19.780% chance of destroying AV11

AV12
4x(88.9%) chance to hit = 3.556 hits at BS4
3.556x (16.7%) chance to penetrate = 0.594 Penetrating Hits
0.594x(33.3%) chance to wreck or explode = 19.780% chance of destroying AV12

AV13
4x(88.9%) chance to hit = 3.556 hits at BS4
3.556x (11.1%) chance to penetrate (16.7% to rend and 66.7% to roll a 3+) = 0.395 penetrating hits
0.395x(33.3%) chance to wreck or explode = 13.154% chance of destroying AV 13

AV14
4x(88.9%) chance to hit = 3.556 hits at BS4
3.556x (5.6%) chance to penetrate (16.7% to rend and 33.3% to roll a 5+) = 0.199 penetrating hits
0.199x(33.3%) chance to wreck or explode = 6.631% chance of destroying AV 14

Twin Linked Lascannon

AV10
1x(88.9%)chance to hit = 0.889 hits at BS4
0.889x(83.3%) chance to penetrate = 0.741 Penetrating Hits
0.741x(33.3%) chance to wreck or explode = 24.675% chance of destroying AV10

AV11
1x(88.9%)chance to hit = 0.889 hits at BS4
0.889x (66.7%) chance to penetrate = 0.593 Penetrating Hits
0.593x(33.3%) chance to wreck or explode = 19.747% chance of destroying AV11

AV12
1x(88.9%)chance to hit = 0.889 hits at BS4
0.889x (50.0%) chance to penetrate = 0.445 Penetrating Hits
0.445x(33.3%) chance to wreck or explode = 14.819% chance of destroying AV12

AV13
1x(88.9%)chance to hit = 0.889 hits at BS4
0.889x (33.3%) chance to penetrate = 0.296 Penetrating Hits
0.296x(33.3%) chance to wreck or explode = 9.858% chance of destroying AV 13

AV14
1x(88.9%)chance to hit = 0.889 hits at BS4
0.889x (16.7%) chance to penetrate = 0.148 Penetrating Hits
0.148x(33.3%) chance to wreck or explode = 4.944% chance of destroying AV 14

The only thing these tables show is the weapons probability to DESTROY a vehicle at the list armor values. I did not take the time to calculate the probability for a simple damage result, which would be dealing with far larger numbers across the board. Additionally, I did not calculate the probability for a Twin linked Assault Cannon because doing a Binomial Distribution and factoring in a reroll across 4D6 is beyond my mathematical prowess. Should anyone care to do so, be my guest.

As you can see, the Assault Cannon performs better than the Lascannon across the board, and when Twin Linked, the Lascannons numbers only just edge out the single Assault Cannons numbers. The only advantage a Lascannon has over an Assault Cannon against Vehicles is range.

Against infantry and MC's the Twin Linked Assault Cannon is also the clear victor with a constant 59.4% chance to cause a wound with no armor save regardless of toughness, plus any additional hits that roll sufficiently high enough to wound but don't rend. Against T8 the Assault Cannon has a 59.4% chance to wound with no armor save and the Lascannon has a 59.3% chance to wound with no armor save. Of course both weapons suffer when you factor cover into the equation but the Assault Cannon still wins overall by a large margin as toughness drops, with more than a 130% chance to kill a Space Marine.

This is why all my Razorbacks have Twin-Linked AsCans. However, when talking about Terminators, I don't know if I'd ever choose an Assault Cannon over a Cyclone, simply for the range. If I am going to be in their face, I am not going to replace a TH/SS or Lightning Claws with an Assault Cannon. And if I am not going to be in their face, I am going to sit at range, over 24" away, if I can help it.

Assault Cannons... why?

Rurouni Benshin — GMT

Well, since everyone's already "Mathhammered" this to death, I'll just say "+1 to Assault Cannons". Statistically speaking, Assault Cannons are in fact superior to CML's as far as being an Anti-Tank weapon is concerned. They only lack the range that a CML brings, but on a Terminator, you're likely to have them close to many other viable targets, as opposed to them sitting in your back field shooting from far away.

Hope that clears things up. If you need further clarification, I'd be more than happy to oblige.

Re:Assault Cannons... why?

Grey Templar — GMT

another thing to consider is that you don't lose your stormbolter when you take the missiles.

this matters against infantry. Whats better? 16 stormbolter shots and 8 Assault cannon shots OR 20 stormbolter shots and 4 Frag missiles.

Assault Cannons... why?

jdjamesdean@mail.com — GMT

I'm a firm believer in Range is King. I'll take a Las/Plas Razor any day over a TL AC razor.

2 weapons opposed to 1
one has twice the range
While the other has the same range It's +1Str, and -2AP and still twinlinked. excelent Termie hunters, MC hunters, Marine Killers etc.

That and I'm a Guard player at Heart and I <3 Vendettas

Assault Cannons... why?

Sir_Prometheus — GMT

jdjamesdean@mail.com wrote:I'm a firm believer in Range is King. I'll take a Las/Plas Razor any day over a TL AC razor.

2 weapons opposed to 1
one has twice the range
While the other has the same range It's +1Str, and -2AP and still twinlinked. excelent Termie hunters, MC hunters, Marine Killers etc.

That and I'm a Guard player at Heart and I <3 Vendettas

Whether range is king depends entirely upon the total army you're runniing, as well as of course the opponent you're facing.

Assault Cannons... why?

puma713 — GMT

Sir_Prometheus wrote:
jdjamesdean@mail.com wrote:I'm a firm believer in Range is King. I'll take a Las/Plas Razor any day over a TL AC razor.

2 weapons opposed to 1
one has twice the range
While the other has the same range It's +1Str, and -2AP and still twinlinked. excelent Termie hunters, MC hunters, Marine Killers etc.

That and I'm a Guard player at Heart and I <3 Vendettas

Whether range is king depends entirely upon the total army you're runniing, as well as of course the opponent you're facing.

Right. The reason I run Twin-linked AsCans on my razorbacks is because I play Blood Angels. They have a 36" threat range on my vehicles. If I played Space Wolves or Vanilla Marines, I'd probably run Twin-linked Lascannons or Lascannon + Plasma Guns.

Re:Assault Cannons... why?

Rurouni Benshin — GMT

Grey Templar wrote:another thing to consider is that you don't lose your stormbolter when you take the missiles.

this matters against infantry. Whats better? 16 stormbolter shots and 8 Assault cannon shots OR 20 stormbolter shots and 4 Frag missiles.

It depends completely on how the list works synergistically. Terminators can be built for both, but when you water down their capabilities, you get a "Jack of all trades, and a Master of none"-type of unit. If you want Anti Infantry, forget the Assault Cannons and CML's all together, and take 2 Heavy Flamers instead. And while you're at it, put on a few Chain Fists for when you do actually get into CC against Walkers or Vehicles.

Point is, gaining 4 Storm Bolter and 4 Frag shots in lieu of 8 Assault Cannon shots will always get you mixed results. In the end, if you were to take a more specialized unit (or just a unit with a better loadout), you're going to get better results. You just need to have the right units supporting each other.

Sir_Prometheus wrote:
jdjamesdean@mail.com wrote:I'm a firm believer in Range is King. I'll take a Las/Plas Razor any day over a TL AC razor.

2 weapons opposed to 1
one has twice the range
While the other has the same range It's +1Str, and -2AP and still twinlinked. excelent Termie hunters, MC hunters, Marine Killers etc.

That and I'm a Guard player at Heart and I <3 Vendettas

Whether range is king depends entirely upon the total army you're runniing, as well as of course the opponent you're facing.

QFT.

Assault Cannons... why?

Sir_Prometheus — GMT

MrEconomics wrote:
bruno.sardine wrote:
Sir_Prometheus wrote:Yeah.....the statistical effects of rending and 4 shots versus a higher strength are one of those things that are a little hard to grasp intuitively. But it is, in fact, one of the best anti-tank weapons in the game...

I've tried to mathhammer this out and as soon as I start getting into the probabilities of rending, etc., I get twisted up. Is this correct?

Assuming everything hits, the lascannon is one shot at S9, so it has a 1/3 chance (represented by rolling a 5 or 6) to penetrate AV14. Clean cut and simple.

Still assuming everything hits, the assault cannon is four shots at S6 with a 1/6 of rending. Rending gives a 2/3 chance to add 2 or 3 AP, which all together, will penetrate AV14. All that gives you an overall 1/9 chance to penetrate with every shot, so 4/9 over a single turn, again assuming everything hits.

Then, going back to account for the shots you'll flat out miss... BS 4 gives you a 2/3 chance to hit. So the single lascannon then has a 2/9 (22.2%) chance to hit and penetrate, whereas the assault cannon has an 8/27 (29.6%) chance... 2/27 (7.4%) higher than the lascannon.

Twin-linked, though, opens up the gap even more. Twin-linked BS4 gives you an overall 8/9 (88.9%) chance to hit, since the 1/3 times you miss, you get another 2/3 chance to hit. A twin-linked lascannon, then, has the same chance to pen AV14 as the original assault cannon, 8/27 (29.6%). A twin-linked assault cannon, though, has a 32/81 (39.5%) chance to pen AV14.... 9.9% higher than even the twin-linked lascannon.

Of course, this totally ignores situational advantages, like cover or how fast the vehicle moved the previous turn.

Lesson learned, I should start shooting my assault cannons against vehicles. Thanks for the heads up!

I'm afraid you have the math wrong for the Assault Cannon. Your Lascannon math is correct, if we're calculating the probability of damaging AV14, as opposed to penetrating AV14, which has a 1 in 6 probability per hit, as you have to roll a 6.

The rules for calculating probabilities boil down to two major things. First, if several events are mutually exclusive, that is, if at most one of them can occur, the probability of one of them occuring is the sum of their individual probabilities. Second, if two events are independent of one another (that is, the fact that one of them occured has no influence on the probability of the other occuring) the probability of both occuring is the product of their individual probabilities.

So, if a single Assault Cannon shot gives you a penetrating hit with probability p, the probability of getting a penetrating hit from all four shots is not 4p, because getting a penetrating hit from shot 1 does not prevent you from getting a penetrating hit from shot 2, etc.

The correct math for the Assault Cannon is this. First, you have a 1 in 12 chance of a hit damaging AV14. This is because you need to roll a 6 to rend, and then roll at least a 3 on the subsequent d3. Since a single shot has a 2 out of 3 probability of hitting, the overall probability that a single Assault Cannon shot damages AV14 is 2/3 * 1/12 = 1/18. The probability that you DON'T damage AV14 is then 17/18 ^ 4 = .7956. The probability that you do damage AV14 is then 1 - .7956 = .2044, or a little better than 20%. The Lascannon is thus slightly better according to this statistic. On the other hand, the probability of getting at least one penetrating hit out of an Assault Cannon is about 14%, while the Lascannon's probability is 11.1%. Twin-linked, the results are still comparable. The Lascannon has a higher probability of doing something, the Assault Cannon a higher probability of getting a pen.

A Melta weapon in Melta range still beats the crap out of both of them. A BS 4 Meltagun has a 48.1% chance of doing something to AV14, and a 38.9% chance of inflicting a penetrating hit. On top of that, it does more damage when you roll on the damage table.

All this considered, a vehicle is still the ideal target for an Assault Cannon, especially if you can shoot it at AV10 or AV11. Most infantry is either not valuable enough per model, or has a 3+ or better save. Even TL against T4 or less, you'll only do a little less than 3 wounds on average.

I don't really feel like re-running or explaining the math, but as far as I know both you Bruno.sardine are incorrect. A assault cannon has a 14.01% chance to "stop" (immobilized/stun) and a 4.85% chance to kill a AV 14 vehicle. A lascannon, conversely, has a 11.11% and 3.70% chance to stop or kill AV 14, respectively. The difference is only more dramatic at lower AVs. So the assault cannon is better at popping vehicles in all cases.

All the calculations, and charts, can be found here on the "calculations" tab of this spreadsheet. Lots of other stuff you might find instructive. https://docs.google.com/spreadsheet/ccc?key=0AnFuN-yY7GTydDNHWnZMUHhXaGdkR3ZYQ1ZGQ2FabXc&hl=en_US#gid=0

Assault Cannons... why?

Deadshot — GMT

"If in doubt, rule of cool, doesn't rhyme, but I don't care"-me.

Assault Cannons... why?

Fire_for_effect — GMT

Haha I like where this thread is going/went. For me, I decided to use Assault cannons. They sound good, the maths works out and I have a ton of them lying around so it´s decided If I ever finish my army I might see how they do in battle.