Battletech Battletech/Battlestar Galactica Crossover - Lucky 13th (the rewrite)

[ShadowArxxy]

The closest thing to an autocannon that BA can haul around is the Bearhunter AC system. Don't forget that most AC-2s (i.e. one of the most common) are 75/76mm cannon based on the ARES cannon concept (which had two versions, a 75mm cannon and a 90mm cannon, both of them able to fire three rounds in a second), probably with some ETC (Electrothermal Chemical) technology put in to give the general 'hypersonic/hypervelocity' descriptors for the rounds going downrange.

On a quick note of that tangent:

It's surprisingly hard to track down specs for said ARES cannon, given that it only existed in an obscure prototype program and half the stuff on the Internet about it is from Sparky's clown brigade. Some sources do refer to it as "hypervelocity", but the only actual muzzle velocity figures I'm seeing are 4800 feet per second for the actual gun, plus penetration testing of the "Delta 3" prototype 75mm DU rounds at 4800 FPS and 5400 FPS with performance on par with the then-standard 105mm M774 round, and later testing of the further improved "Delta 6" prototype at unspecified velocity with 430mm RHA penetration at 2000 meters range. Said Delta 6 was basically squeezing every ounce of performance they could out of the round, and that is damn impressive penetration for something so small, but it wasn't enough to handle expected future threats so the program was cancelled at that point.

All of that would place them at high velocity, but not full-fledged hypervelocity.

Edit: That said, what is your source for AC-2s being 75-76mm? Per Sarna, the Armstrong AC-2s on the Vulcan battlemech are 60mm, and the Whirlwind-L AC-2s on "older" Blackjacks are 40mm; those are the only ones mentioned with explicit canon calibers.

 

[Aaron Fox]

On a quick note of that tangent:

It's surprisingly hard to track down specs for said ARES cannon, given that it only existed in an obscure prototype program and half the stuff on the Internet about it is from Sparky's clown brigade. Some sources do refer to it as "hypervelocity", but the only actual muzzle velocity figures I'm seeing are 4800 feet per second for the actual gun, plus penetration testing of the "Delta 3" prototype 75mm DU rounds at 4800 FPS and 5400 FPS with performance on par with the then-standard 105mm M774 round, and later testing of the further improved "Delta 6" prototype at unspecified velocity with 430mm RHA penetration at 2000 meters range. Said Delta 6 was basically squeezing every ounce of performance they could out of the round, and that is damn impressive penetration for something so small, but it wasn't enough to handle expected future threats so the program was cancelled at that point.

All of that would place them at high velocity, but not full-fledged hypervelocity.

The canon for Battletech's ACs tends to go within the 'hypersonic'/'hypervelocity' velocity range, and this is despite the fact that there are almost four decades of Battletech to contend with. Also please note that a lot of the Cold War got into the Battletech creation process, especially the idea of a 'broken back' war...

Edit: That said, what is your source for AC-2s being 75-76mm? Per Sarna, the Armstrong AC-2s on the Vulcan battlemech are 60mm, and the Whirlwind-L AC-2s on "older" Blackjacks are 40mm; those are the only ones mentioned with explicit canon calibers.

This is actually from data mining from the HBS game Battletech (which the main campaign is canon, given that it has its own sourcebook, not to mention made with the original creator of Battletech itself!) and using a rather effective algorithm to put out the numbers.

Using this data mining, we get:

• AC-2s being 78mm in caliber firing 3-round bursts, thus making each ton of ammo being 75 distinct rounds or 25 'shots' (aka bursts)... which falls in line with the ARES 75mm when it got to the production prototype stage.
• AC-5s being 98mm in caliber firing in 3-round bursts, thus making each ton of ammo being 45 distinct rounds or 15 'shots'... which falls in line with the ARES 90mm when it got to the prototype stage.
• AC-10s being 114mm in caliber firing in bursts (I remember AC-10s being 2-round bursts but I haven't played the game in a while), thus making each ton of ammo being 24 distinct rounds for eight 'shots' which is in line with a rumored (at least to me, as I can't find anything on it) ARES 105mm prototype autocannon.
• AC-20s being 193mm in caliber firing in semi-auto, with each ton of ammo being 5 rounds/shots each. This is roughly in line with a soviet 180mm cannon that got mistaken as an 8" gun...

Using this data mining and shot mass as a basis, we get these sort of numbers for the various artillery pieces:

• Long Toms being 203mm howitzers ala their Cold War namesakes
• Snipers being 155mm howitzers ala Cold War NATO/Soviet field howitzers (being 155/152mm respectively)
• Thumpers being 122mm howitzers/field guns ala Soviet 'direct fire' artillery
• Arrow IV missiles being 200mm guided rockets, ala Soviet BMD-20s

It should also be noted that Mechwarrior 5 Mercenaries also helped in rationalizing the fact that some ACs are semi-auto and some are burst-fire with the addition of Burstfire Autocannons (and to be frank, I've seen videos of them in action, and it's like aiming with a bipod mounted MG-42 on full-auto, they just go everywhere instead of where you want them to go).

 

[LordSunhawk]

That's data mining from a mod, not the base game, plus HBS stats are not necessarily accurate. Note that I do like the rationalized ARES approach, but I'm leaving the numbers fuzzy

 

[Aaron Fox]

That's data mining from a mod, not the base game, plus HBS stats are not necessarily accurate. Note that I do like the rationalized ARES approach, but I'm leaving the numbers fuzzy

The thing is, the ARES approach does make a ton of sense overall, so keeping the weapons along those lines would be very plausible. It should also be noted that in practically all Battletech non-game centric visual media (even the non-canonical cartoon that became an in-universe propaganda piece), BT 'mechs and vehicles tend to die in less than a minute...

Then again, the only BA-mounted autocannon before the BA LBX showed up is the Bearhunter and is a 3-barreled monstrosity that sacrificed range to its rate of fire and firepower.

 

[ShadowArxxy]

This is actually from data mining from the HBS game Battletech (which the main campaign is canon, given that it has its own sourcebook, not to mention made with the original creator of Battletech itself!) and using a rather effective algorithm to put out the numbers.

As Sunhawk pointed out, you're actually citing a totally unofficial game mod, i.e. fanon.

Moreover, the Battletech game does not actually count as canon in its game mechanics as opposed to plot events, and arguably even then only insofar as those events are reiterated by the sourcebook. And at best, it shows that ACs of those calibers exist and were used by the protagonist mercenary unit; it doesn't even prove they were common models.

 

[Doomsought]

AC-10s being 114mm in caliber firing in bursts (I remember AC-10s being 2-round bursts but I haven't played the game in a while), thus making each ton of ammo being 24 distinct rounds for eight 'shots' which is in line with a rumored (at least to me, as I can't find anything on it) ARES 105mm prototype autocannon.

The tech manual explicitly says that the classifications are a generalization, and different models might have a slightly lighter or heavier caliber with more or less burst fire to compensate. This isn't limited to AC, most LRM-20 have 20 tubes, but the LRM-20 on the Atlas has 5 tubes that are each fired 4 times in rapid succession.

 

[Aaron Fox]

As Sunhawk pointed out, you're actually citing a totally unofficial game mod, i.e. fanon.

Moreover, the Battletech game does not actually count as canon in its game mechanics as opposed to plot events, and arguably even then only insofar as those events are reiterated by the sourcebook. And at best, it shows that ACs of those calibers exist and were used by the protagonist mercenary unit; it doesn't even prove they were common models.

The core thing with these numbers is that they're closest to the likely inspirations of the weapons themselves...

 

[ShadowArxxy]

Again, it has always been canon that Autocannons are a wide variety of calibers which are balanced by burst rates. The evidence you have presented *at best* shows that 75-76mm AC2s *might* exist; it does not even begin to show that they are standard or universal.

 

[Aaron Fox]

Again, it has always been canon that Autocannons are a wide variety of calibers which are balanced by burst rates. The evidence you have presented *at best* shows that 75-76mm AC2s *might* exist; it does not even begin to show that they are standard or universal.

While true, that makes it just a major headache logistically... but you're right in that regard.

 

[ShadowArxxy]

While true, that makes it just a major headache logistically... but you're right in that regard.

It's *supposed to be* a logistical nightmare. Outside of the video game abstraction, you literally can't order autocannon ammo without specifying the exact make and model you're loading, because even when the caliber is the same, there's absolutely no reason to believe the shells are intercompatible. Everything is proprietary.

 

[Aaron Fox]

It's *supposed to be* a logistical nightmare. Outside of the video game abstraction, you literally can't order autocannon ammo without specifying the exact make and model you're loading, because even when the caliber is the same, there's absolutely no reason to believe the shells are intercompatible. Everything is proprietary.

You would think that the Inner Sphere would have decided to standardize during the Star League... you know so you can use the enemy's ammunition (like what happened during the Civil War, the US and CSA regularly used each other's ammunition)...

 

[Jarow]

You would think that the Inner Sphere would have decided to standardize during the Star League...

It's worse than you'd think from that - it's not just 5 sets of autocannon ammo (1/great house) - it's at least one set for every manufacturer. So something like 14 different AC/20 ammo types, at least according to Sarna (wouldn't be surprised if there are more than that in actual practice).

 

[Aaron Fox]

It's worse than you'd think from that - it's not just 5 sets of autocannon ammo (1/great house) - it's at least one set for every manufacturer. So something like 14 different AC/20 ammo types, at least according to Sarna (wouldn't be surprised if there are more than that in actual practice).

As I said, you would think that the Inner Sphere would start standardizing during the Star League because if there is anything that history tells them it's that logistics wins wars...

 

[Jarow]

Standardization would be pretty smart; it's one thing Griffin's Roost in Sunhawk's quest is trying to do (for itself at least).
In canon, it looks like people are designing weapons to fit in mechs though, rather than mechs to fit the weapons. Beyond that, I guess some people like using a 10 shot burst of 150mm, and others like using 200mm?

 

[Bear Ribs]

As I said, you would think that the Inner Sphere would start standardizing during the Star League because if there is anything that history tells them it's that logistics wins wars...

Megacorporations in BattleTech don't get as much play but what we see indicates that they're incredibly powerful and controlling, probably on par with Shadowrun. They like their monopolies and nonstandard parts so they force it on the Great Houses. ComStar is the most successful and gets the most story but all BattleTech corporations tend to use a similar method of force and manipulation, albeit not often with religion mixed in.

Apple has it's own planet it renamed Macintosh.

 

[ShadowArxxy]

In principle, it would be consistent with both canon and fluff for an autocannon manufacturer to streamline all of its product line to use the exact same caliber, with the distinction between AC 2, 5, 10, and 20 being entirely in burst.

However, the rules would not allow this to lead to the creation of an AC-Variable that could be reconfigured on the fly.

 

[UltimatePaladin]

In principle, it would be consistent with both canon and fluff for an autocannon manufacturer to streamline all of its product line to use the exact same caliber, with the distinction between AC 2, 5, 10, and 20 being entirely in burst.

However, the rules would not allow this to lead to the creation of an AC-Variable that could be reconfigured on the fly.

Yeah, way too much flexibility for autocannon. Assuming that you would need an AC/20 to get access to the entire lineup (needing more mass/volume to deal with recoil. Admittedly also mass-intensive,) you’d end up with a platform with no “minimum” range, that can shift between firing at targets, long distance, before pounding anything that makes the mistake of getting up close. Speaking as someone who thinks autocannons should get a buff, yeah, no.

Probably not something the THiE has in store - it’s one of those setting breaking things that are theoretically possible, but that no one wants to do. Though, it would be a variable LB-X or Ultra in that case...

 

[Aaron Fox]

Yeah, way too much flexibility for autocannon. Assuming that you would need an AC/20 to get access to the entire lineup (needing more mass/volume to deal with recoil. Admittedly also mass-intensive,) you’d end up with a platform with no “minimum” range, that can shift between firing at targets, long distance, before pounding anything that makes the mistake of getting up close. Speaking as someone who thinks autocannons should get a buff, yeah, no.

Probably not something the THiE has in store - it’s one of those setting breaking things that are theoretically possible, but that no one wants to do. Though, it would be a variable LB-X or Ultra in that case...

As someone that has been trying that sort of thing, I understand. There are some sacred cows that the setting has and the more diehard fans are more than willing to tear you apart if you sacrifice them. One of those sacred cows is that, for the most part, there have to be several downsides to a weapon system...

 

[Bear Ribs]

For my own writing I avoid variable autocannons by making the assumption that the shells in a burst are not all the same bullet. Rather, it fires a "cartridge" of bullets which are designed so that the first few rounds don't do any damage but "soften" the armor by radiation and vibration and only the last couple of rounds ablate the prepared softened armor point to actually do damage. This is also why ranges get shorter as AC damage increases, you have to keep the entire stream on a tight grouping or the penetrator rounds won't hit the softened armor spot, so with an AC/2 firing only two to five rounds, you need merely keep it on track for a hundredth of a second but an AC/2 will hit with 45 rounds and you need to keep on-target for a full half-second and that's just not as doable on a moving 'mech at a distance.

This is entirely pulled from my backside as far as canonicity, mind you.

 

[Aaron Fox]

For my own writing I avoid variable autocannons by making the assumption that the shells in a burst are not all the same bullet. Rather, it fires a "cartridge" of bullets which are designed so that the first few rounds don't do any damage but "soften" the armor by radiation and vibration and only the last couple of rounds ablate the prepared softened armor point to actually do damage. This is also why ranges get shorter as AC damage increases, you have to keep the entire stream on a tight grouping or the penetrator rounds won't hit the softened armor spot, so with an AC/2 firing only two to five rounds, you need merely keep it on track for a hundredth of a second but an AC/2 will hit with 45 rounds and you need to keep on-target for a full half-second and that's just not as doable on a moving 'mech at a distance.

This is entirely pulled from my backside as far as canonicity, mind you.

I would have thought of that as well in my younger years, but if you look up the ARES cannon concept, it makes far more sense. The sad thing is that there aren't many videos on the ARES family.