Zandel_Corrin
12/01/08 04:37 AM
59.101.172.151
|
Ok so what are the AC sizes?
20 - 50mm? 100 - 200mm?
does anyone know?
Galaxy Commander
Zandel Corrin
Night Dragon Clan
|
MacLeod
12/01/08 04:51 AM
24.6.94.252
|
The glossary in my old printing of Blood of Kerensky: Blood Legacy says:
"Light vehicle autocannon range from 30 to 90mm caliber, while heavy 'Mech autocannon may be 80 to 120mm or more."
Drugs don't kill people, pancreatic cancer kills people.
... and whoever heard of a drug that causes pancreatic cancer?
|
Cray
12/01/08 08:34 AM
147.160.136.10
|
Quote:
Ok so what are the AC sizes?
20 - 50mm? 100 - 200mm?
does anyone know?
Yes. Stories and Tech Readouts have given wide ranges to each class. They break down like this:
An AC/2 fires 22.2kg of shells per "shot."
An AC/5 fires 50kg of shells per shot.
An AC/10 fires 100kg of shells per shot.
An AC/20 fires 200kg of shells per shot.
A "shot" is a combination of caliber and rate of fire such that the noted mass of shells is fired. For example, one model of AC/2 might be a 105mm cannon that fires 1 shell per turn, while another model might be a 25mm weapon that fires 20-40 shells per turn.
As another example, AC/20s have been spotted at 120mm, 150mm (Hetzer), 185mm (Demolisher, Monitor), and 203mm (Cauldron Born UAC/20).
AC/5s tend to fall into the 50-90mm range, but there have been outliers. AC/10s tend to fall into the 75 to 120mm range, but their have been outliers.
The maximum caliber of an AC is such that it fires its entire weight of shot as a single shell (roughly: 105mm for AC/2, 120mm for AC/5, 203mm for AC/10, 250mm for AC/20). The minimum is probably about 20mm, maybe 25-30mm for the AC/20. A 20mm M61 Vulcan (at 6600 rounds per minute and 0.1kg per shell) can deliver up to 100kg per 10 seconds, matching the performance of an AC/10.
Mike Miller, Materials Engineer
Disclaimer: Anything stated in this post is unofficial and non-canon unless directly quoted from a published book. Random internet musings of a BattleTech writer are not canon.
|
Christopher_Perkins
12/01/08 10:01 PM
76.104.32.151
|
One of the outliers for the AC/5 class was the 120 mm GM Whirlwind that fired 3 Shells per Burst (or BattleTech "Round" - Shot still means individual shell in BattleTech RPG 3rd Edition... ) mounted on the TR-3025 (Tech Level-D) Marauder
at 1,000 kg / 20 kg = 50 kg per burst / 3 = 16.67 kg per shell The Shells fired from the GM Whirlwind AC/5 aren't quite as massive as the 18.64 kg m829 120 mm shell fired from the Rheinmetall L/44 smoothbore gun (called M256 in the US) mounted on the M1A1 and M1A2. (53 shots/shells per ton)
Christopher Robin Perkins
It is my opinion that all statements should be questioned, digested, disected, tasted, and then either spit out or adopted... RHIP is not a god given shield
|
Cray
12/01/08 11:33 PM
12.168.4.209
|
Quote:
at 1,000 kg / 20 kg = 50 kg per burst / 3 = 16.67 kg per shell The Shells fired from the GM Whirlwind AC/5 aren't quite as massive as the 18.64 kg m829 120 mm shell fired from the Rheinmetall L/44 smoothbore gun (called M256 in the US) mounted on the M1A1 and M1A2. (53 shots/shells per ton)
The 150mm shells of the Hetzer are positively anorexic. The Hetzer's gun fires 10 shells per shot, pegging them at 10kg each.
Mike Miller, Materials Engineer
Disclaimer: Anything stated in this post is unofficial and non-canon unless directly quoted from a published book. Random internet musings of a BattleTech writer are not canon.
|
Zandel_Corrin
12/02/08 08:11 PM
123.2.140.247
|
so there's no hard and fast rule then....
I can't see an AC firing only 1 shell as that makes them cannons and not AutoCannons...
Technically i guess anything over 1 shell is an AC but i tend to think of them as semi machine gun affairs...
anyone else see them different? I liked how they were represented in the Mech 3 computer game... A stream of bullets that fire in bursts each time you pull the trigger.
Galaxy Commander
Zandel Corrin
Night Dragon Clan
|
Christopher_Perkins
12/02/08 10:03 PM
76.104.32.151
|
actually what makes a Cannon an Autocannon is the Autoloading Mechanism
this means that there isn't a man slaved to the gun feeding its Shells, so an Autocannon that fires one shell every 10 seconds is still a massive improvement.
Consider that a trained Abrams crew (i.e. a trained loader, and a gunner who can find the trigger with both hands) fires like 5-7 shells a minute... (The US doesnt go in for Autoloading mechanisms for some reason... any cannon cockers / red legs or tankers care to weigh in?)
60 / 7 = 1 shell every 8 seconds (3 2.5 Second Solaris IV (BT 2ed) turns)
60 / 6 = 1 shell every 10 seconds (4 2.5 Second Solaris IV (BT 2ed) turns) / 1 BT Turn
60 / 5 = 1 shell every 12 seconds (5 2.5 Second Solaris IV (BT 2ed) turns)
The Pontiac 100 AC/20 on the Victor is so named because it fires a burst of 100 30mm shells, and almost all of the supposedly large hole standard Autocannon are actually a large barreld protective covering around small barrel rotary autocannon (with only one spin rate).
Christopher Robin Perkins
It is my opinion that all statements should be questioned, digested, disected, tasted, and then either spit out or adopted... RHIP is not a god given shield
|
Christopher_Perkins
12/02/08 10:35 PM
76.104.32.151
|
Quote:
Quote:
at 1,000 kg / 20 kg = 50 kg per burst / 3 = 16.67 kg per shell The Shells fired from the GM Whirlwind AC/5 aren't quite as massive as the 18.64 kg m829 120 mm shell fired from the Rheinmetall L/44 smoothbore gun (called M256 in the US) mounted on the M1A1 and M1A2. (53 shots/shells per ton)
The 150mm shells of the Hetzer are positively anorexic. The Hetzer's gun fires 10 shells per shot, pegging them at 10kg each.
1000 kg / 5 "rounds" per ton = 200 kg per burst / 10 shells per burst = 20 kg per shell, still about half the weight of a WWI 150 mm Cannon shell (41 kg).
in BattleTech RPG 3rd Edition terms... its AP 7, 88 d6, Splash... running this back through the IPCR, a single shell does 14 BT Damage, and it takes 10 shells to make it to 20... (IPCR Formula... go figure)... looks like 2 shells hit and the rest bounce from a weapon fluffed as "accurate" ... oookaayyyy...
Christopher Robin Perkins
It is my opinion that all statements should be questioned, digested, disected, tasted, and then either spit out or adopted... RHIP is not a god given shield
|
Zandel_Corrin
12/03/08 02:02 AM
123.2.140.247
|
yeah fluff is strange... just look at pulse lasers and targeting comps..... no way that should work... EVER.... not for accuracy.... maybe damage tho...
Galaxy Commander
Zandel Corrin
Night Dragon Clan
|
Cray
12/03/08 10:34 AM
97.97.243.184
|
Quote:
Technically i guess anything over 1 shell is an AC but i tend to think of them as semi machine gun affairs...
They're fully machine gun affairs, and described as such in countless bits of BT fiction, not to mention the latest rules (Tech Manual, pg207):
Quote:
For what amounts to one of the most basic combat systems on
the modern battlefi eld, autocannons (often abbreviated as ACs) are
a broadly varied class of rapid-fi ring, auto-loading, heavy ballistic
weaponry—gigantic machine guns, in other words. With calibers
ranging from 30 to 90 millimeters at the lighter end, to as much as 203
millimeters or more at the heaviest, most autocannons deliver their
damage by fi ring high-speed streams or bursts of high-explosive,
armor-defeating shells through one or more barrels. While caliber
and fi ring rate can vary greatly, four main classes have emerged over
the centuries, setting the standards by which all other ACs are rated,
based on their relative ballistic damage. At the lightest end is the AC/2
class, followed by the long-time standard AC/5, then the heavy punch
of the AC/10 class, and fi nally the brutal, close-in AC/20.
Mike Miller, Materials Engineer
Disclaimer: Anything stated in this post is unofficial and non-canon unless directly quoted from a published book. Random internet musings of a BattleTech writer are not canon.
|
Cray
12/03/08 10:35 AM
97.97.243.184
|
Quote:
Quote:
The 150mm shells of the Hetzer are positively anorexic. The Hetzer's gun fires 10 shells per shot, pegging them at 10kg each.
1000 kg / 5 "rounds" per ton = 200 kg per burst / 10 shells per burst = 20 kg per shell, still about half the weight of a WWI 150 mm Cannon shell (41 kg).
Yep, yep, I know. I had a total brain fart. I called the Hetzer's gun an AC/20 in one post, then got it stuck in my head that it was an AC/10 in the next post. Yes, 20kg each.
Mike Miller, Materials Engineer
Disclaimer: Anything stated in this post is unofficial and non-canon unless directly quoted from a published book. Random internet musings of a BattleTech writer are not canon.
|
Cray
12/03/08 10:44 AM
97.97.243.184
|
Quote:
yeah fluff is strange... just look at pulse lasers and targeting comps..... no way that should work... EVER.... not for accuracy.... maybe damage tho...
I disagree about accuracy. Pulse lasers don't hose a target with many pulses in hopes of some hitting. Their pulse effect is doing something very different than "spray and pray."
The to-hit bonus of pulse lasers stems from giving armor ablation products a chance to disperse. Conventional continuous-beam lasers can literally waste a lot of their energy just scorching paint, since the first touch of the laser produces plasma at the beam contact site that is highly opaque to laser light. (Such plasma absorption is the basis for laser welding, though laser welding can exploit keyhole effects denied to battlefield weaponry.)
Thus, it's more difficult for standard lasers to "bite" into the armor of the target and a lot of shots may be wasted. By strobbing the laser at millisecond intervals, you give enough time for the plasma to disperse and the next laser pulse can hit fresh armor, hence the to-hit advantage of pulse lasers.
See pg226 Tech Manual for the "physics" of pulse lasers. The same description also appeared in the Blood of Kerensky trilogy when, IIRC, Phelan Kell was introduced to pulse lasers.
("The pulse laser uses rapid-cycling, high-energy pulses to generate multiple
laser beams, creating an eff ect comparable to machine-gun fi re. But
because the staggered pulses give the protective ablation products from
combat armor a chance to disperse—to expose fresh armor to subsequent
pulses—the result is a burst of fi re that is more eff ective and accurate.")
Effectively, the pulse laser is a normal laser for all targeting purposes. You point and click. No need to lead the target, no need to allow for time of flight, but a pulse laser can benefit from the stabilization offered** to standard lasers - an attacker bounding over hills and rough terrain will jitter their pulse beam off target like any other laser. Thus, a targeting computer will work fine.
(**pg238 Tech Manual: "More than just a
basic sensor tracking and targeting array, the targeting computer actually
helps its gunner aim physically. This is accomplished through a series of
recoil compensators and gyroscopic stabilizers that combine to counter
much of the routine weapon drift caused by the shooter’s own lurching
motions, muzzle recoil and other environmental conditions.")
Mike Miller, Materials Engineer
Disclaimer: Anything stated in this post is unofficial and non-canon unless directly quoted from a published book. Random internet musings of a BattleTech writer are not canon.
|
Zandel_Corrin
12/03/08 05:56 PM
123.2.140.247
|
oh wow.... that's new.... never seen the bit about the ablation products...
That does make sense now tho.... ok i can see targ comps working then
I did always wonder why the never mentioned anything about that in reference to lasers....good to see it's on track now.
Galaxy Commander
Zandel Corrin
Night Dragon Clan
|
incognito
12/03/08 05:57 PM
68.153.113.2
|
deflation of the ablation
munch munch on anti-HoC
|
Cray
12/03/08 08:56 PM
97.97.243.184
|
Quote:
deflation of the ablation
Pretty much.
Mike Miller, Materials Engineer
Disclaimer: Anything stated in this post is unofficial and non-canon unless directly quoted from a published book. Random internet musings of a BattleTech writer are not canon.
|
Christopher_Perkins
12/04/08 11:43 PM
76.104.32.151
|
Single Shell per Burst Autocannon are outliers for their damage class as much as the 100 Shot per Burst Pontiac is an outlier for the Autocannon 20 Class
Single Shot Autocannon/2 = 1000/45 = 22.22 kg per shell
Single Shot Autocannon/5 = 1000/20 = 50 kg per shell
Single Shot Autocannon/10 = 1000/10 = 100 kg per shell
Single Shot Autocannon/20 = 1000/5 = 200 kg per shell
No good / easy to use resource for ammo mass exists... outside of wiki...
and inside of wiki, its hard to use and hard to trust.
Christopher Robin Perkins
It is my opinion that all statements should be questioned, digested, disected, tasted, and then either spit out or adopted... RHIP is not a god given shield
|
Zandel_Corrin
12/05/08 01:56 AM
123.2.140.247
|
just for the feel of it i'd tend to say 5 - 10 shells per burst
Autocannon/2 = 1000/225 (5 shell) = 4.45 kg per shell
Autocannon/5 = 1000/100 (5 shell) = 10 kg per shell
Autocannon/10 = 1000/50 (5 shell) = 20 kg per shell
Autocannon/20 = 1000/25 (5 shell) = 40 kg per shell
Autocannon/2 = 1000/450 (10 shell) = 2.22 kg per shell
Autocannon/5 = 1000/200 (10 shell) = 5 kg per shell
Autocannon/10 = 1000/100 (10 shell) = 10 kg per shell
Autocannon/20 = 1000/50 (10 shell) = 20 kg per shell
looking at that i might stick with 5 shell bursts but i'm not sure what the calibure should be.... any ideas?
Galaxy Commander
Zandel Corrin
Night Dragon Clan
|
Christopher_Perkins
12/05/08 11:32 PM
76.104.32.151
|
What ever an author wants to use, an author can
there are no right or wrong answers in this... (some choices like the half massed hetzer shells.... make you go "humm?!??")
lower minimum is 1 Shell, upper maximum 100 shells... (and that is only because i havn't seen any thing higher)
Most common in the fluff is 10 shell bursts however...
Sarlon Autocannon/2 on Warrior H-7 is a 30 mm Cannon with a 10 Shot Burst.
Luxor-D Autocannon 10 on the Centurion is a 70 mm cannon with a 10 shot burst
KaliYama Autocannon/10 on the Orion is a 90 mm cannon with a 5 Shot Burst.
Most Autocannon 20's are said to be 120 mm cannon with a 10 shot burst.
Christopher Robin Perkins
It is my opinion that all statements should be questioned, digested, disected, tasted, and then either spit out or adopted... RHIP is not a god given shield
Edited by Christopher_Perkins (12/06/08 12:22 PM)
|