52 replies to this topic

[Grayseven]

There has been a lot of talk lately about how bad AC/5's are, so I thought I'd play around a bit with a build comparison.

Using a JM6-S chassis I took my standard dual AC/20 build and replaced the 20's with quad AC/5's.

The chassis without weapons:

250 XL engine (62.3Kph base)
Endo-Steel structure
Double heat sinks
384 points standard armor

In both builds, I have a pair of medium lasers (1 LT, 1 RT)

Now we come to the interesting part...

2x AC/20's weigh in at 28 tons

4x AC/5's weight in at 32 tons

This is the biggest drawback that I've found. That 4 tons of weight difference between the two load outs may not seem like much, but it's a killer. That's because...

Weight remaining for ammo for the AC/20 build is 7 tons. That comes out to 49 shots.

Weight remaining for ammo for the AC/5 build is 3 tons. That comes out to 90 shots.

It takes 4 rounds of AC/5 ammo to do the same damage as 1 round of AC/20 ammo, but the weight per shot ratio actually favors the AC/5 over the AC/20...albeit ever so slightly.

Based off of total damage available, however, the 7 tons of AC/20 ammo has a maximum damage output of 980 points versus the 450 points the 3 tons of AC/5 ammo gives.

Where the AC/5's shine is in three main categories: Heat, Cycle Time and Range.

The heat of a pair of AC/20's firing off is 12. To do the same amount of damage requires 2 salvo's from the AC/5's for a total of 8 heat.

The cycle time of an AC/20 is 4 seconds compared to the 1.7 seconds of an AC/5. For initial shots, the AC/20 has the advantage but over a prolonged fire fight the AC/5 will begin to put out more damage after the second AC/20 salvo. Before a dual AC/20 mech can fire its 3rd salvo for a total of 120 damage, a quad AC/5 will have put out 7 salvos for 140 points of damage.

Range, for me, seemed to be a big advantage of the AC/5's. The AC/5 has twice the range of an AC/20...unfortunately I can not find hard numbers as to how ballistic damage drops off at range so I can not be absolutely certain as to whether or not the AC/5 has a damage advantage over the AC/20 at ranges beyond the "optimal" or long range of the weapon. At 800 meters against the CT of a Catapult, the dual AC/20's didn't seem to do a lot of damage, 3 salvos only turning the armor yellow but not taking the damage percentage below 99%. At 540 meters, the salvos were doing 3% per and at 270 they pulled off 6%. Simple extrapolation of data would mean the AC/5 would do similar damage percentages at 1600m, 1080m and 540m (That is, full damage up to long, half damage up to twice long and minimal damage at "extreme" ranges).

However, even given the range and heat advantages of the AC/5 and understanding that the cycle time only becomes an advantage after 8 seconds of sustained fire, it seems that the AC/5 is still an inferior choice which only becomes more apparent when you factor in other weapons systems like the Gauss Rifle and the UAC/5.

What could be done to make the AC/5 more attractive? For one, I believe simply taking the shots per ton of ammo from 30 to 50 would help tremendously. With that simple move you close the gap between total damage output by 300 points for this build without changing the weapons balance too much since shots taken at longer ranges have a tendency to miss much more than the point blank shots the 20's are known for. I'm not certain that shaving even a half ton of weigh from the AC/5 wouldn't upset weapons balance somehow except that it would allow for another 2 tons of ammo in this build and would have the same net effect as changing the shots per ton would.

All said, AC/5's seem to be exactly what a number of people have said...poor choices in any load out.

[TexAce]

good analysis.

I still think all ACs except the AC20 are waaay too heavy. Why should I ever pack two AC10s when i can pack one AC20, whether heat nor range make it a good option over one AC20.

Edited by TexAss, 11 April 2013 - 07:24 AM.

[zztophat]

Good analysis and I agree. However in my Atlas I will still mount dual UAC5s over a single 20 because of the large damage difference and the lack of weight concerns on the chassis.

Edited by zztophat, 11 April 2013 - 07:27 AM.

[Signal27]

OP: dual Gauss Rifles is another popular load out. How would you say quad AC5s stack up against dual Gauss?

[Sadistic Savior]

I prefer AC/20s only because of the stopping power. All the damage in one spot, at one time. That is great for headshotting and delivering killing blows when part of a swarm. Because of this, AC/20s are more fun IMO.

AC/5s are great for range, but I suck at long ranged ballistics anyway. I really wanted to like them, but I don't have the skills to use them effectively.

[TexAce]

Sadistic Savior, on 11 April 2013 - 07:32 AM, said:

I prefer AC/20s only because of the stopping power. All the damage in one spot, at one time. That is great for headshotting and delivering killing blows when part of a swarm. Because of this, AC/20s are more fun IMO.

AC/5s are great for range, but I suck at long ranged ballistics anyway. I really wanted to like them, but I don't have the skills to use them effectively.

With state rewind for ballistics coming very soon, this might change a bit

[Viper69]

TexAss, on 11 April 2013 - 07:23 AM, said:

good analysis.

I still think all ACs except the AC20 are waaay too heavy. Why should I ever pack two AC10s when i can pack one AC20, whether heat nor range make it a good option over one AC20.

Redundancy more than anything I would guess and range.

[Khobai]

AC/5s are bad because they fire way too slow.

AC/2 = 4 dps
AC/5 = 2.9 dps
AC/10 = 4 dps
AC/20 = 5 dps

The AC/5 cooldown should be 1.25 instead of 1.7 to give it dps consistent with other autocannons.

[BGrey]

Signal27, on 11 April 2013 - 07:29 AM, said:

OP: dual Gauss Rifles is another popular load out. How would you say quad AC5s stack up against dual Gauss?

I tried 4ac5 and 2guass on my 4x and felt much better with the AC5s. The gauss projectile speeds are rather slow and the slow rate of fire just felt lacking when directly engaging an enemy mech.

Its also important to note that the ac20/ac5 comparison is only really relevant for the jager mech considering that the 4x cant fit the ac20 but also that the phract has the additional tonnage for ammo that the jager doesn't. From that I would say stick to the ac20s on a jager, if you want 4AC5 then go with a 4x.

Edited by BGrey, 11 April 2013 - 07:48 AM.

[Grayseven]

Signal27, on 11 April 2013 - 07:29 AM, said:

OP: dual Gauss Rifles is another popular load out. How would you say quad AC5s stack up against dual Gauss?

The same chassis allows me to pack 50 rounds (5 tons) of gauss ammo for a total damage potential of 750 points with greater range and less heat than both the 20's and the 5's. Gauss guns are above and beyond the best choice and one I use quite frequently even though state rewind hasn't been put into place for ballistics yet.

Less important in the above analysis, but still important, is the psychological impact of the various weapons systems as well as the firing options. When I run dual 20's I tend to have them both fire together. The sheer impact power can strip a location of armor on most mechs (and in one memorable shot, blow the leg off a spider at 400m who was silly enough to jump to the top of a building in frozen city and stop). For the gauss at sniping ranges I tend to chain fire them at moving targets because leading at 1000m is a little bit skill and a lot bit luck. Psychologically I feel that the AC/5's in chain fire have a far greater effect than their damage would indicate. The incessant clatter of continuous AC shots has to be one of the most annoying things I've experienced and I like to share that experience from time to time...though mostly in my Cataphract 4X because the extra weight available allows for a few more tons of ammo.

The only problem with gauss rifles is their tendency to blow up when destroyed and take the side torso (and XL engine) with it. Other than that, I feel that the gauss build is all around the best choice for that chassis.

Edited by Grayseven, 11 April 2013 - 07:51 AM.

[Rashhaverak]

In these discussions I question the logic of thinking that the AC/20 and four AC/5's should somehow be equivalent. That for some reason the damage output or weight or usefulness of weapons should be equal.

I think that logic is flawed. Each weapon has strengths and weaknesses, and changing their characteristics to make them more equal is actually undesirable. Changing the AC/5 so that four of them equal, or more closely equate to, an AC/20 is a bad idea that will lower the complexity and variety that is a key part of this game's greatness.

The machine gun should not be equivalent to a small laser, the AC/10 should not be equivalent to the PPC, and so forth. Each weapon should retain unique character so that different builds will actually be different, and add to the variety and depth of the game.

[Roland]

The main advantage of the dual AC20's over quad AC5's is that you have a 40 point alpha as opposed to a 20 point alpha.

Putting down 40 points is infinitely more powerful than putting down 20 points twice.

[Belorion]

TexAss, on 11 April 2013 - 07:23 AM, said:

good analysis.

I still think all ACs except the AC20 are waaay too heavy. Why should I ever pack two AC10s when i can pack one AC20, whether heat nor range make it a good option over one AC20.

Not saying its a good reason, but sometimes one ac 20 just doesn't fit...

[TexAce]

Belorion, on 11 April 2013 - 07:57 AM, said:

Not saying its a good reason, but sometimes one ac 20 just doesn't fit...

how? visually? or hard point restrictions? Latter I would understand but former not.

[Grayseven]

Rashhaverak, on 11 April 2013 - 07:51 AM, said:

In these discussions I question the logic of thinking that the AC/20 and four AC/5's should somehow be equivalent. That for some reason the damage output or weight or usefulness of weapons should be equal.

I think that logic is flawed. Each weapon has strengths and weaknesses, and changing their characteristics to make them more equal is actually undesirable. Changing the AC/5 so that four of them equal, or more closely equate to, an AC/20 is a bad idea that will lower the complexity and variety that is a key part of this game's greatness.

The machine gun should not be equivalent to a small laser, the AC/10 should not be equivalent to the PPC, and so forth. Each weapon should retain unique character so that different builds will actually be different, and add to the variety and depth of the game.

I fully agree. However, in analyzing the choices I made it a point to look at all aspects of the weapons in question. The problem with the AC/5 comes in that overall there are much better choices out there. 3 UAC/5's in the same chassis far outperform the quad AC/5's even if you never double tap and jam the weapons...i.e. chain fire them...since they have a recycle rate of 1.1 and 3 UAC/5's weight 27 tons compared to the 32 tons of quad AC/5's and you can fit 200 rounds of ammo for those guns. That is 1000 potential damage for those who are counting. The burst damage potential is far and above what even dual 20's can do if you are lucky with the jamming...

[MaddMaxx]

Roland, on 11 April 2013 - 07:53 AM, said:

The main advantage of the dual AC20's over quad AC5's is that you have a 40 point alpha as opposed to a 20 point alpha.

Putting down 40 points is infinitely more powerful than putting down 20 points twice.

Based solely on circumstance. If we find out early your packing 2 20's, you will not find that shortish range you absolutely need so easily and eat way more than 2 20 volleys on the way in.

Edited by MaddMaxx, 11 April 2013 - 08:09 AM.

[RainbowToh]

Thontor, on 11 April 2013 - 07:59 AM, said:

Damage drops linearly out to 3x optimal range.

Two AC/20

• 40 damage at 270m
  
• 35 damage at 337.5m
  
• 30 damage at 405m
  
• 25 damage at 472.5m
  
• 20 damage at 540m
  
• 15 damage at 607.5m
  
• 10 damage at 675m
  
• 5 damage at 742.5m
  
• 0 damage at 810m

Four AC/5

• 20 damage at 540m
  
• 15 damage at 810m
  
• 10 damage at 1080m
  
• 5 damage at 1350m
  
• 0 damage at 1620m

Two AC/20s and Four AC/5s do the same alpha strike damage at 540m. And the AC/5 does it a lot more often, consuming fewer tons of ammo per damage done at that range. Beyond 540m the AC/5 has a clear alpha strike advantage.

Where did you get the figures for the range damage drops?

[Grayseven]

As an addendum to this post:

I just took a Tri UAC/5 out for a spin. Just chain firing them I managed 1 kill, 5 assists and over 400 damage with 50 rounds left. I did use some of the ammo to "keep their heads down" during an initial rush by their team over the ridge in frozen city and went toe to toe with an Atlas that seemed a bit put off by the constant rattle of fire.

I did have some problems leading a fast Treb which accounts for most of the misses...

[Demos]

Khobai, on 11 April 2013 - 07:40 AM, said:

AC/5s are bad because they fire way too slow.

AC/2 = 4 dps
AC/5 = 2.9 dps
AC/10 = 4 dps
AC/20 = 5 dps

The AC/5 cooldown should be 1.25 instead of 1.7 to give it dps consistent with other autocannons.

Totally shortsighted IMHO.
With the same DPS, the bigger ACs would have lower damage because they are heavier, they create more heat and have a shorter range.
So a DPS per ton of weapon would be the maximum and here only the AC/2 have a distinct advantage.

I'd prefer 2,25sec for AC/10 and 1,5sec for AC/10.
AC/2 and AC/20 could remain.

Edited by Demos, 11 April 2013 - 08:36 AM.

[Roland]

DPS isn't really a useful metric in Mechwarrior anyway, since it's all about precision damage, not just spraying damage at an enemy.