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1) I've heard that the mathhammer says assault cannons have a slightly higher chance of killing tough vehicles compared to lascannons. Is this true, and is it something to take into account with an army?

2) Also if it is, what is the fluff explaination? A fast gun doesn't seem like it would peirce better than dedicated anti-armor.

3) And I heard Space Wolves are getting a Land Raider with assault cannon sponsions, is this true?

4) And lastly, are assault cannons related to punisher guns? They are both miniguns, and how do they compare?

1) You have to hope for a lot of 6s when rolling to penetrate for the Assault Cannon to actually damage AV 13/14 vehicles. AFAIK, the Assault Cannon does deal more damage to AV 14 vehicles...

3) That's the rumour. We'll have to wait and see, I suppose.

4) Not really. They're both Imperial guns with an incredibly high rate of fire. Comparatively, the Punisher Gun spits out way more fire, and usually does about the same amount of damage (except against vehicles).

Osyr wrote:1) I've heard that the mathhammer says assault cannons have a slightly higher chance of killing tough vehicles compared to lascannons. Is this true, and is it something to take into account with an army?

2) Also if it is, what is the fluff explaination? A fast gun doesn't seem like it would peirce better than dedicated anti-armor.

3) And I heard Space Wolves are getting a Land Raider with assault cannon sponsions, is this true?

4) And lastly, are assault cannons related to punisher guns? They are both miniguns, and how do they compare?

1- Well- at first this sounded very unlikely with the mathhammer....but, using batches of 1000 weapons (1000 shots for LC's and 4000 for AC's)against Av14 a lascannon runs about 11-12% chance per shot to glance or penetrate. Assault cannons run about 4% per shot .....not what I was expecting at all Since assault cannons get a smaller chance per shot...but fire 4 times as many shots....means against heavy armor theyre nearly as effective, and as the armor gets lighter they get more an more effective...

2-Umm, I'll point at a real-world equivalent of the GAU-8 in the A-10. And this is 40k, fluff and game stats dont always coincide

3-Its possible but who knows at this point...

4- Totally unrelated. Assault Cannons are a tried & true part of the imperial arsenal, the Punisher laser is a recent addition and only found on one model of Leman Russ tanks. The AC fires bullets, the Punisher shoots lasers. The punisher is most effective against lightly armored troops, it has little effect on vehicles other than unarmored ones.

Go with Assault Cannons because they a dual purpose gun which is the most important thing on building a good balanced force.

The Forgeworld Vulture can have punisher guns, and those have ammo cans, I doubt they are lasers. So why if they gun is bigger does it not peirce armor the same, since they both shoot similarly fast.


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I need to proof-read

Rending is fairly badly nerfed in 5e, but still leaves the AC more effective than the Lascannon.

Mom, I think your Mathhammer is off...

BS4 Lascannon
Glance : 1 shot, .667 hit, .111 Glance (roll a 5)
Glance : 1 shot, .667 hit, .111 Pen (roll a 6)

Doing the MathHammer for an Assault Cannon is more complicated, since you need to look at a binomial distribution. First you get the chances of Glance and Pen with an AC.

Glance: 1 shot, .667 hit, .037 Glance (roll a 6 then 3-4)
Pen: 1 shot. 667 hit, .037 Pen (roll a 6 then 5-6)

From there, the binomial distribution for either result looks the same...

0: 1.000 (0.860)
1: 0.140 (0.132)
2: 0.008 (0.008)
3: 0.000 (0.000)
4: 0.000 (0.000)

That's the output of a stupid little app I wrote, it's not particularly clear, but what it's saying is the odds of each result, 0 Pens, 1 Pen, 2, etc. So, the odds of getting 2 pens, is .8%. The odds of 1 is 13.2% (better than the Lascannon), and the odds of 1 or more is 14%.

So, you're looking at 14% (with a possibility for more than one effect) vs. 11%.

The Assault Cannon is superior against AV14, but not nearly as much as it used to be. In general, Assault Cannons remain very effective, one of the most flexible, reliable weapons in the game.


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Also if it is, what is the fluff explaination? A fast gun doesn't seem like it would peirce better than dedicated anti-armor.

Well, it doesn't. The odds of a single Assault Cannon shot defeating AV14 is almost 1/4th that of a Lascannon. It's just that it shoots 4x as much. So, really it's shooting worse, faster.

Fluffwise, consider the GAU-8 vs the average tank cannon. The cannon on the average battle tank is very powerful, say 120mm, and can kill tanks. However, good enough armor can shrug off a cannon shell. By comparison, the 30mm GAU-8 pretty much never fails to kill a tank it's fired on, even though an individual shot from it isn't particularly powerful. You put enough of them on target, one is going to find a shell trap, hit the target's aiming systems, tracks, etc.

Sure, it's shooting at thinner top armor, but you get the idea.

I'd say the difference is probably in the type of ammo used.

Assault cannons are generally on elite platforms like dreads, land raiders, terminators and to a lesser extent speeders and razorbacks. The gun fits with the versatility that marines seem to demand from everything.

Guard on the other hand are keen on specializing most of the time. The trade off in this case is rate of fire vs stopping power.

I guess what I'm saying is its like Hollow-points vs armor piercing.

Phryxis wrote:The Assault Cannon is superior against AV14, but not nearly as much as it used to be. In general, Assault Cannons remain very effective, one of the most flexible, reliable weapons in the game.

I agree, however I think its useful to take some lascannons if possible, because else the monoliths just gonna laugh at you.

Well at least thats true for me, dunno how many necron players you guys are facing

Lasers?!

How awesome!

Something else to consider is the range of these weapons. The lascannon can be effective from turn 1 on while the 24" AC might not have any immediate targets.

In reference to the Gau-8, it's the depleted uranium rounds that make it so damn effective.

The mathhammer is pretty simple on this one, and was correctly done above. Without requoting too much, against AV14, the assault cannon has about a 14% chance overall vs a lascannons 11%.

It's off because if you get a rend, you're already hitting AV12, then a roll of a 3 or 4 gets you a glance on AV14, 5 or 6 is a pen. Sheer volume of fire will account for more actual damage rolls than the potential one from the lascannon.

However, the Lascannon is far from useless. A 48" range of control is something too useful to pass up, and the lascannon is excellent against AV11 and AV12 transports; eg, where it should be used. I personally would like to see it AP1, being as that it's designed as a can-opener, but i guess that would OP it.

The one thing I can say is that a T-L Lascannon it worth it's weight in gold at transport popping. Razorbacks with TL Las give you a really good chance at controlling the transport wars. You don't want to wait till you're within 24" to start shooting in these days of MeltaMadness.

Also, Lascannons make great sniper rifles. Try using one for a quick InstaKill on a Crisis Battlesuit, or pretty much any SM HQ or random other high-value target. Back in 4th, I used to use the 6 man Las-Plas squad x 4 every game, and I can tell you from experience, even without armor targets, the Lascannon has a place and a job on the field.

Osyr wrote:The Forgeworld Vulture can have punisher guns, and those have ammo cans, I doubt they are lasers. So why if they gun is bigger does it not peirce armor the same, since they both shoot similarly fast.


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I need to proof-read

I would agree on the solid ammo front. Given the existing models of the punisher I don't see it as a laser weapon. Just because the gun is bigger doesn't make it more powerful. Barrel length will affect accuracy, rather than penetrating power. The penetration would be based on round composition and charge power.

@Flagg07 - Compared to modern tungsten cored APFSDS penetrator rounds

Don't forget that the Avenger tends to be fired at the top armour of its targets.

I'd also like to second the point about a Lascannon's range.

The Assault Cannon basically leverages the number of hit/wound/armour dice it rolls, plus the effects of the Rending universal special rule, since roll four dice tends to iron out the effect of bad luck on single dice rolls.

That said, the extra 24" range on the Lascannon tends to iron out the effect of people effectively shooting back at you, or you being out of range.

In reference to the Gau-8, it's the depleted uranium rounds that make it so damn effective.

Sure, but a sabot round for a tank cannon is typically DU as well. Anything that's a kinetic penetrator benefits from mass.

Barrel length will affect accuracy, rather than penetrating power. The penetration would be based on round composition and charge power.

Actually not true. The longer the barrel, the more time the charge has to work on the projectile. Obviously there's a diminishing return, and the charge's volume and burn rate have to match the barrel, but if you're looking to make a high velocity weapon, you give it a long barrel.

A simple example would be to compare the M-16 to the M-4. The M-16, with its longer barrel, provides marginally more muzzle velocity firing the same ammunition.

That said, the extra 24" range on the Lascannon tends to iron out the effect of people effectively shooting back at you, or you being out of range.

Based on the costs GW has given Razorback weapons, one assumes they feel that Assault Cannons are about equal to Lascannons (the costs are the same).

I tend to disagree with them, but not by much. Lascannons are still very useful weapons. For some reason people have been really down on them in 5e, but they're still worth a look in most lists.

Each has their place in the game.

Assault Cannon is nice to take out infantry along with a chance to take out light-medium vehicles with ease.

The lascannon is 1 shot but packs a wallop. It can tear through most light and medium but can also take care of heavy vehicles. Plus the 48 inch range makes sure your out of the ranges of other tank hunting weapons such as meltas and lances.

you can have flexibility or you can have range.

oh FYI:
Light vehicles (av 10-11)
Medium vehicles (av 12-13)
Heavy vehicles (av 14)

Phryxis wrote:
A simple example would be to compare the M-16 to the M-4. The M-16, with its longer barrel, provides marginally more muzzle velocity firing the same ammunition.

Same ammunition is the key part of this. With ammunition designed to optimise the shorter barrel (faster burn rate) and a rifling rate optimised for that ammo then the difference would be negligible. However, the ammunition would be unusable in the longer barrelled guns.

ETA, barrel length & twist rate (which are required to stabilise the selected weight of projectile) are the main limiting factors for performance. Military examples are of little relevance as the ammunition is required to be interchangeable (unless you're french in which case you design a slightly modified round which doesn't work for anybody else just to get a couple of percent of performance improvement). Even DMR rifles (which are issued with specialised ammunition) are constrained by being required to retain reasonable performance with standard ammunition.

So, lets talk about the velocity increase for putting a longer barrel on Las weapons.... oh wait....speed of light x ..... damn that Einstein...he was right....


Seriously guys- the difference in the m4 and m-16 examples arent about velocity- its more about the role each design was intended for. M-16 open field combat, M-4 multi-purpose with an emphasis on urban enviroments. Its sort of a classic Rifle Vs Carbine debate. Has very little to do with Lascannon and assault cannons.

We arent talking about small arms

Doing some math...it actually seems that the Assault cannon is better against all armor values (assuming BS 4).

Las:
AV 14: 4/6(1/6) = 11.11%
AV 13: 4/6(2/6) = 22.22%
AV 12: 4/6(3/6) = 33.33%
AV 11: 4/6(4/6) = 44.44 %
AV 10: 4/6(5/6) = 55.55%

Assault Cannon:
AV 14: 1-(1-(4/6)(1/6)(2/6))^4 = 14%
AV 13: 1-(1-(4/6)(1/6)(4/6))^4 = 26.5%
AV 12: 1-(1-(4/6)(1/6))^4 = 37.6%
AV 11: 1-(1-(4/6)(2/6))^4 = 63.4%
AV 10: 1-(1-(4/6)(3/6))^4 = 80.2%

Just to explain the assault cannon equation. First take your chance to hit/pen with a single shot (for this example vs. AV 14):

(4/6)(1/6)(2/6) = 8/216

Then subtract this number from one to figure your chance of not getting a penetrating hit:

1-(8/216) = 208/216

Then multiply that number to the power of how many shots you are shooting with this weapon (which is 4).

(208/216)^4 = .8599

Finally, subtract that number from one again.

1-.8599 = .1401 (14%)

This is just the math for getting at least one penetrating hit with each individual weapon. All the math should be correct, but I am prone to mistakes so feel free to make sure I haven't messed anything up.

Assault Cannon rules!! Period.

Assault cannons are madness against anything they kill stuff fast.

Hay even as an eldar player love my assault cannon (AKA Maugetar) only thing it can't kill are monoliths. In fact Monoliths are the only vehicle worth taking LasCannons against. (but why are you shooting the monolith, and not shoot the Necrons i don't know)

The math definitely says the AC is better against vehicles -- which, honestly, it should be, since the LC has better range and AP. One thing to note if you play eldar a lot is that the AC is unaffected by the Wave Serpent's energy field, and is thus even better compared to the LC in that context.

As for the effectiveness of a real-life AC-style weapon vs. a lascannon, the trick is explaining why *any* laser weapon would ever be used outside of deep space. Generally if you have the energy to kill something with a laser, you can kill it far more efficiently by throwing something hard at it. So fluff-wise the AC seems more believable. =)

The whole Assault Cannon thing was a bit of a cock-up from the start. Originally, in 3rd edition the Assault Cannon had three 'shots', and a rule that rendered it useless if three 1s, a misfire, were rolled. This was after 2nd edition where the Assault Cannon rolled three sustained fire dice, for a possible nine shots, and exploded with three Jam results. Gotta admit the graphic for it firing was cool though.

But instead of giving it 4th edition Rending, or adding an Attack, or simply getting rid of the obnoxious misfire result, they gave it all three!

Still, with a range of 24", the Lascannon wins on slow movers like Dreadnoughts, particularly Venerable Dreadnoughts.

Nurglitch wrote:

Still, with a range of 24", the Lascannon wins on slow movers like Dreadnoughts, particularly Venerable Dreadnoughts.

Twin linked Las runs 30 pts more than the assault cannon on a dread , and is less effective. A drop pod is 35

Mistress of Minis wrote:Twin linked Las runs 30 pts more than the assault cannon on a dread , and is less effective. A drop pod is 35

Incorrect. The Twin-Linked Lascannon 20pts more than the Assault Cannon on both the Venerable Dreadnought and the Dreadnought. The Twin-Linked Lascannon is 30pts, the Assault Cannon is 10pts.

The Assault Cannon is only effective out to 24". The Lascannon is effective out to 48" range. So the Lascannon wins between 25"-48" hands down.

By all means drop your Dreadnought into Melta range of the enemy though.

Space Wolves like to play it close. Assault cannons all the way for me, as I have always played it.

Twin linked Las runs 30 pts more than the assault cannon on a dread , and is less effective.

Less effective against what?

The test case we're using here seems to be against AV14, where the T-L Las is much more comparable.

T-L BS4 Lascannon
Glance : 1 shot, .889 hit, .148 Glance (roll a 5)
Glance : 1 shot, .889 hit, .148 Pen (roll a 6)

That's compared to the .14 of the Assault Cannon for similar results.

On the other hand, the AC has .008 odds of getting 2 results, which if you count double and add to the .14, you end up with .148. Identical...

Phryxis wrote:

Twin linked Las runs 30 pts more than the assault cannon on a dread , and is less effective.

Less effective against what?

The test case we're using here seems to be against AV14, where the T-L Las is much more comparable.

T-L BS4 Lascannon
Glance : 1 shot, .889 hit, .148 Glance (roll a 5)
Glance : 1 shot, .889 hit, .148 Pen (roll a 6)

That's compared to the .14 of the Assault Cannon for similar results.

On the other hand, the AC has .008 odds of getting 2 results, which if you count double and add to the .14, you end up with .148. Identical...

A T/L lascannon has the same effectiveness as the AC vs AV14- But- against everything else the AC is more effective- the lighter the armor gets the more damage the AC does- where as the LC will only ever get one hit. Against infantry the strength of the lascannon, is only its range, and ability to snipe IC's for instant kills. Otherwise, for firing at squads/mobs, and even MC's, the AC turns out better results.

Oh dear, ive just released a hidden-gem of a force multipler.

Lascannons - What makes it good; High strength & good range.

Assault cannons - What makes it good; Okay strength combined with rending coupled with multiple shots.

What does BS5 improve more? A single shot lascannon or a heavy 4 shot assault cannon? (I am curious and am not sure).

I know twin-linked on BS5 nets somthing like a 97% accuracy per shot.

Whilst four shots @ bs5 should net you a consitent 3 shots. So whats 3 assault cannon rounds vs 1 lascannon round, range not factored?

On razorbacks, crusaders, and redeemers assault cannons are twin-linked too.

@Razerous, by my shoddy math, there is a 50% chance of one 6 on the assault cannon, So it's essentially 50% chance of a S12+1d3 , which glances on a 2 or pens on a 3 vs AV14, whereas the lascannon has a 16% chance of rolling a 6, or a 32% chance of rolling a 5-6, to pen or glance, So the assault cannon has a 34% chance of nailing a pen or glance if it gets 3 hits, whereas the lascannon has a 32% chance. Now considering you get roughly 3.5 hits at BS5, compared to 0.97 lascannon hits, the assault cannon is even better.

tl;dr assault cannon still wins, I know what im putting on my razorbacks.