Post/Author/DateTime	Post
#1 anshin_mandango Feb 10, 2009 20:21:58	Hiya, i've been doing some poking around, and I was just wondering if anybody has any stats for really big guns like the 80cm Gustav railway gun or even bigger, like the 100cm version that was researched but never made. If those stats are unavailable, then smaller, but still BIG guns like those that serve as main guns on battleships would also work. Basicly, what I intend to do is stick a bunch of these on a spaceship, lasers and missles are cool and all, but they just lack the intimidation factor of having a ridiculously huge cannon pointed right at you.
#2 backstabbist Feb 10, 2009 21:38:56	I did up an Arty HE Shelling formula a longtime ago that uses the Bore to get the damage, and has a diminishing damage & RefDC with distance from the blast point. I adapted it to a set of Tankgun Formulas for Tema's(?) WW2 thread (I'll find a link to that) Anyhoo, basicly[INDENT] just for fun I did up a formula based system for popping HE Arty Shells on guys last year (hmm, year before?)... cause shelling folks is fun. In a nutshell, for Artillery HE Shells [INDENT]Take 1d8 for each 10mm bore Drop 1d8 for each 5'sq the guy is from the point of impact RefSave DC is 11+ #of dice (hmmm, was that it, or 15+... cant recall) 75mm PackHowitzer shell bursts with GuyA 15' away, and GuyB 25' away. GuyA: 7d8 (75mm) -3d8 (15') = 4d8, Ref DC (11+ 4) = DC15 GuyB: 7d8 (75mm) -5d8 (25') = 2d8, Ref DC (11+ 2) = DC13 So the small guns aint so super deadly.... but do it again with a 155mm Shell: GuyA: 15d8 (155m) -3d8 (15') = 12d8, RefDC (11+ 12) = DC23 GuyB: 15d8 (155mm) - 5d8 (25') = 10d8, RefDC (11+ 10) = DC21 GuyC: 15d8 (155mm) -12d8 (60') = 3d8 , RefDC (11+ 3) = DC14 [/INDENT] so as you can see, the best way to survive a big arty shell is to not be next to it when it hits.... GuyC standing 60' away is in ok shape, but you dont wanna be the guy 15' from a 100lb shell going BANG! Without using my formula, in general, you should look at the Area / Radius of the shells you posted, and grow it so 20lb shells have bigger blasts than a hand grenade.[/INDENT] where the heck is that WW2 Tank thread... Using NavalGuns on spaceships Turrets & Tracking have to be turbocharged to train & lead, fortunately in the future there could easily be ten 2000horsepower traverse drivers that could allow that gbig turret to fwip around back & forth pretty darn quick. Time Of Flight Given the lax attitude toward MIssiles in space needing to get from point A to point B, there shouldnt be a problem with a 3000fps (36sq/round) getting the same treatment Really big the 16" AP could punch 30" thick RHA steel then go bang with 40lb of high explosives. If we ignore the 1000 damage impact, that is still 40lb of bang... even when loaded with what would be Museum Explosives in a space fight, that is like 40x 2d6/lb explosives Really big nerf Alas, look at what they gave the 1 Megaton Nuke
#3 anshin_mandango Feb 10, 2009 21:48:40	awesome, that is exactally what I was looking for, since now I can take a collassal 100cm gun, and size it up all the way to Superheavyweight spaceship scale...as soon as I decide exactally how big that gun would be, anyway, thanks a bunch!
#4 AnimeSniper Feb 11, 2009 14:34:22	There is always the Magnetic Accelerator Cannon or MAC gun that is often deployed on military starships for those one shot one ship kills, well if you can manage to line the single shot and fire without missing, at least how its portrayed in SF Books... give me time to consult my Warship PDF and a few other ref docs I have and I may come up with something for you...
#5 backstabbist Feb 11, 2009 15:16:47	I think he is failing to grab onto the Nerf. If we make a 100' diameter bore for a 4000' long barrel that thumps out a shell carrying 1.5 billion pounds of RE 1.3 explosives to target that is just 16d8 damage ala 1 MegaTon Nuke
#6 Cyber-Dave Feb 11, 2009 21:00:59	I wish I still had a copy of my Starship Weapons document lying around in easy reach. It was designed to do exactly what you want it to do. It was scaled against the FTLB scale of modern weapons. It started out with weapons that were pretty much just big machine guns, and went up all the way to singularity bombs that could take out solar systems. Unfortunately, I stopped using modern in favor of Star Wars Saga, and put all that work in storage. Unless someone else has a copy available for you, I don't have easy access to it myself anymore.
#7 Ragitsu Feb 12, 2009 2:20:29	Imagine using D&D's weapon sizing rules for d20 Modern. Tiny Remington 870 anyone? How about a Colossal Beretta Cougar 9000? Diminutive flamethrower?
#8 backstabbist Feb 12, 2009 9:49:55	You hit the size cap, Max Colossal. A Colossal Firearm is a 1hand gun for a 70' dude: Sure the biggest pistol a colossal 70' dude could use is a Tankgun, but what size gun does that 70' guy use as a 2Handed Rifle? Colossal+ 8" Navalgun on a cruiser? What size is the 16" Navalgun... Colossal++ ? Besides, we already know the insane sums of damage from a 70' Robot's ginormous Rifle: Warpath RR nerfapaloosa, not tankguns
#9 Ragitsu Feb 12, 2009 14:52:31	Remember the "Pocket Machinegun" topic? :D It involved a pocket sized M2HB that did full damage and had the full range increment preserved.
#10 backstabbist Feb 12, 2009 15:56:21	Of course I remember that one, it is my defacto example of why the Gadgets Compact & Miniaturization logically dont work on firearms, along with being a great lead-in to the future weapon damage Nerf/Cap discussion. Compact/Miniature firearms would need to use a more potent future gunpowder, like UberGunPowderExtreme (UGPX) to get the same bang with less size. Which logically should be a whole new weapons platform with guns in all nominal role sizes using PL6 UGPX Guns more power than PL5 gunpodwer guns. PL6 Laser platform makes more potent weapons than PL5 Gunpowder, and PL7 Plasma technology make more potent weapons than pl6 Lasers... obviously PL6 UGPX platform would have all sizes roles of weapons more powerful than pl5 gunpowder. Which also brings up Recoil: Sure we can make a pistol with the power of a 600ne/50BMG but who is going to be able to hold onto that? The problem isnt making cannons small enough to be pistols, its making guys big enough to hold onto PistolCannons. Even ETC doesnt erase total recoil impulse, it just spreads the spike out a bit but will still slam the cannon out of your hands.
#11 Ragitsu Feb 15, 2009 2:00:34	A Small sized M249!
#12 backstabbist Feb 15, 2009 10:28:50	Oh, yeah they make smaller stuff: it is absolutely all about the scale, as demonstrated in this capture clearly documenting the different scales standing in front of a hedge/bushes 128' robot with a 20"RailcarGun LargeMech for 40mm autocannons Lil Girl Powerarmor & 20mm ATR If I could do a widescreen capture we prbably could have seen the Pixie with AK47 farther left off screen.:P Too bad RAW has all of those mechs doing the same damage with WarpathRR in just one size
#13 Waylan_Wolf Feb 15, 2009 11:49:16	Oh, yeah they make smaller stuff: Too bad RAW has all of those mechs doing the same damage with WarpathRR in just one size Thats why I ignore RAW when it doesn't make sense. I had written up a whole document of "big guns" on the D20 Past forum, but its gone now... if I can find the original in my hard drive i'll re-post it.
#14 Waylan_Wolf Feb 15, 2009 14:12:33	Thats why I ignore RAW when it doesn't make sense. I had written up a whole document of "big guns" on the D20 Past forum, but its gone now... if I can find the original in my hard drive i'll re-post it. here's what I had come up with... Machine guns M60 machine gun 2d10 (DC10+RAB), ignores 5 hardness, range increment 400' large .50 cal machine gun 2d12 (DC10+RAB), ignores 6 hardness, range increment 400' huge 20mm/25mm/30mm cannon 4d12 (DC10+RAB), ignores 8 hardness, range increment 150' huge Rotary Cannons 7.62mm minigun 2d10 (DC20+RAB), ignores 5 hardness, range increment 400' huge 20mm tri-barrel chain gun 4d12 (DC15+RAB), ignores 8 hardness, range increment 150' huge 20mm vulcan cannon 4d12 (DC20+RAB), ignores 8 hardness, range increment 150' gargantuan 30mm avenger cannon 6d12 (DC20+RAB), ignores 10 hardness, range increment 300' gargantuan Antitank Cannons 40mm cannon 6d12 (DC10+RAB) to target hit and 3d6 to all within 10' blast radius, ignores 5 hardness, range increment 300' huge 3" gun/76mm/88mm/90mm cannon 7d12 damage to target hit and 4d6 to all within 10' blast radius, ignores 6 hardness, range increment 300' huge 4" gun/105mm cannon 8d12 damage to target hit and 4d6 to all within 15' blast radius, ignores 8 hardness, range increment 350' gargantuan 120mm cannon/5" gun 10d12 damage to target hit and 5d6 to all within 20' blast radius, ignores 10 hardness, range increment 400' colossal Artillery Cannons PL3 Light Cannon 8 pounder 5d6 damage to target hit and 5d6 to all within 5' blast radius, range increment = 60' huge Medium Cannon 16 pounder 10d6 damage to target hit and 10d6 to all within 15' blast radius, range increment 100' gargantuan Heavy Cannon 32 pounder 15d6 damage to target hit and 15d6 to all within 45' blast radius, range increment 120' colossal PL4 6" gun/155mm howitzer/250lb shell 22d6 damage to target hit and 1d6x10 to all within 25' blast radius, range increment 3,000' colossal 8" gun/200mm howitzer/500lb bomb 24d6 damage to target hit and 3d6x10 to all within 50' blast radius, range increment 4,000' ultralight 12" gun/1,000lb bomb 28d6 damage to target hit and 6d6x10 damage to all within 100' blast radius, range increment 6,000' light 16" gun/2,000lb bomb 30d6 damage to target hit and 12d6x10 damage to all within 150' blast radius, range increment 8,000' light Rockets Bazooka 4d6 to target hit and to all within 15' radius ignores 6 hardness RPG7 6d6 to target hit and to all within 15' radius ignores 8 hardness LAW/AT4 10d6 to target hit and to all within 20' radius ignores 10 hardness TOW/TOW II Missile 16d16 to target hit and to all within 20' radius ignores 10 hardness Hellfire/Maverick Missile 18d6 to target hit and to all within 20' radius ignores 15 hardness
#15 skipsandwich Feb 23, 2009 9:11:53	I worked out a table based on Backstabbist's weapon damage table scaling the various gun types from d20 future to different sizes. I ended up with 81d12 for a Superheavyweight sized cannon, and 243d12 for the same size disentegrator. My rationale for scaling is based on the observation that disentegrator weapons are 3x as powerful as ballistic wepaons of a comparable caliber/size.
#16 backstabbist Feb 23, 2009 10:51:32	This is just an appearance thing, but... in the tabel you just posted you have "Gauss" as a post Plasma weapon tech. I believe you meant to use the term "Grav". Gauss is magnetic drive, while Grav is artificial gravity. Both are slugthrowers, but Gravguns are superior tech & performance. "Railgun" in RAW is actually a Gravgun using artificial gravity control rather than a magnetic gaussgun. No big deal. Yeah, Disintegrators are good, but short ranged. You can have balancing factors in both Ranges and Rate Of Fires. Perhaps Cannons: Rate Single (can do +11/+6/+1 but not DoubleTap) Navalguns: Rate 1 & Reloadtime 1 Superguns: Rate 1 & Reload/charge times of 1/2/3 for Light/med/heavy Supercannon: Rate 1 & Reload/Charge time of +2 each nominal size .... LargeSupercannon= 6charge then 1 to fire <16" mains on Iowa were like 2 shots per minute>
#17 skipsandwich Feb 23, 2009 16:45:42	I'm aware of the difference between Gauss and Grav weaponry, its just that I personally think that gauss sounds cooler, and its what I imagine when I think of railguns anyhow, so its what I went with for the label for that tech. You are right that the destinction between the two should be noted for the benifit of others, though. The main purpose of this table was to figure out the damage that would be dealt by each successively larger caliber/bore/equivilant measure of firepower for each of the firearm technologies, I have yet to actually make any weapons of larger then huge size with this, but your suggestion about increased load/charge times is a good one, one that i'll keep in mind when I get around to making a new table of starship weapons that don't fail as badly as the 16d8 nuke. :EDIT: Oh, and also, it should be noted that these figures are the damage from direct hits, and anything of navalgun size or larger is probablly going to do significant collateral damage as well, of a scale that i've yet to determine, due to having very little practicall RL knowledge of guns.
#18 AnimeSniper Feb 23, 2009 19:10:19	I wish I still had a copy of my Starship Weapons document lying around in easy reach. It was designed to do exactly what you want it to do. It was scaled against the FTLB scale of modern weapons. It started out with weapons that were pretty much just big machine guns, and went up all the way to singularity bombs that could take out solar systems. Unfortunately, I stopped using modern in favor of Star Wars Saga, and put all that work in storage. Unless someone else has a copy available for you, I don't have easy access to it myself anymore. I think I have a printout of that post... let me check my filing cabinet and binders tonight... and if someone knows a good free posting site I can low key PDF it and then post/link it for you....
#19 backstabbist Feb 23, 2009 21:34:48	Skip: Big guns have big bullets Its a matter of Nerf, and how much of it you want. The FIRST lb of explosives is twice as bangy as all the following lbs. The 1st lb of C4 is 4d6 and all additional lbs are just 2d6: If you blow a 1lb block of high explosives (C4), its 4d6 10lb case C4 = 4d6 + 9(2d6) = 22d6 But lets UberNerf it for the sake of discussion to all all lbs high explosives do 1d6: If you just go downto the magazine and hit the fuse of a shell that is just sitting there, 155mm HE shell 15lb bursting charge, 15d6 mk82 500lb dumb bomb 192lb bursting charge 192d6 16" HC 150lb bursting charge = 150d6 of area kablooie 16" AP slug 40lb bursting charge, 40d8 The Armor Piercing (AP) shell fired by these guns is capable of penetrating nearly 30 feet (9 m) of concrete, depending upon the range and obliquity of impact. The High Capacity (HC) shell can create a crater 50 feet wide and 20 feet deep (15 x 6 m). During her deployment off Vietnam, USS New Jersey (BB-62) occasionally fired a single HC round into the jungle and so created a helicopter landing zone 200 yards (180 m) in diameter and defoliated trees for 300 yards (270 m) beyond that. my HE Shelling forumla only gives the 400mm(16"shell) 1d6 at 200' from center (66yd) and 30d6 to guys 50' away from center
#20 skipsandwich Feb 23, 2009 23:07:25	hmmm, under your formula posted above, the 80cm gustav would do 80d8 damage to anything at ground zero, with a DC 90ish reflex save for half damage, which is comparable to that of the medium supercannon on my chart (average damage 360 for the gustav, 351 for the medium supercannon), which would make the heavy supercannon something like 120cm in diameter, or almost 4 ft across...holy #&%! that's a big gun!
#21 AnimeSniper Feb 25, 2009 18:32:48	okay Here are the links to a few of CyberDave's earlier posts in the archive; Starship Weapons: http://boards1.wizards.com/showthread.php?t=796685 Mecha Sensors: http://forums.gleemax.com/wotc_archive/index.php/t-739960 Starship Vehicle Rules:http://forums.gleemax.com/wotc_archive/index.php/t-741307 Enjoy
#22 backstabbist Feb 25, 2009 19:26:40	hmmm, ran into a snag with a 8" gun under d20Mecha computation A 200mm gun would have 20d8 under my formula, but I changed it to 16d12 to fit a set of guns from 40-200mm. 16d12 with 80'r Blast would be 16x 13 x 8<80'blast> having a single 8" gun on your Mech is over 1800 points... without any mech to hold the gun old table
#23 skipsandwich Feb 28, 2009 21:52:51	hmm... that's weird, are you adding any restricitons? cause when I compute it with either Blast or Armor Penetratingx4, Indirect Fire, and the Slow Firing restriction, I come up with a price of 520 mecha points for either ammo type, one of which gets reduced to 52 mecha points for being an alternate ammo, for a total price of 572 mecha points for the whole gun. :Edit: I think I see where you're going wrong, the blast quality DOUBLES in radius each time you take it, so you only need to take it 4 times for a radius of 80', that combined with 90% price reduction on alternate ammo types, should lower the cost some.
#24 backstabbist Mar 01, 2009 11:31:08	Well, I wasnt too fixated on having 3 different ammos on board as much as getting a decent primary gun of a given size/caliber. Thanx for finding the Blast doubling that I missed... the big guns were getting way too expensive when I missed that, 520? I'm just looking at the basic mech gun, as Rifle or Armgun, a primary weapon for big combat vehicles. Rate Single, Standard Range (&fudge), 4xBlast(10, 20, 40, 80') 16Dice x 13DieSize, times 4Qualities = 208 x 4 = 816 I figured to have a mech/vehicle be worth the same to a character whether it is loaded with HE or AP ammo. The gun is of the same power, to drive a light KE slug or thump a payload HE shell. Active Munitions can be additional cost, but again the gun system needs to interface with the smart ammo which is a Gun cost upgrade to make it a SmartShell Capable gun. BatteryGuns(arty), RapidFire, Autocanon, RotaryCanon, Longrange/Carbine would have different charts, mainly due to smaller or larger bore/damages for differnt systems: While a single ROF Huge(-2) would be like ~40mm, a Huge(-2)RotaryCanon would be a 20-23mm doing less damage but Auto/Burst capable... so different table.
#25 skipsandwich Mar 02, 2009 7:49:34	yeah, if you want to lower the cost any further, you're going to have to start adding restrictions, because as far as I can tell, your math is now correct. Some restrictions are going to be dependant on exactally what you mount the guns on, though. For example, a 15" gun mounted on a battleship probablly isn't going to have the Static restriction, but one used as a cannon on a bipedal mecha large enough to carry it probablly would, but in both situations the Slow Firing restriction would fit well.
#26 backstabbist Mar 02, 2009 11:14:51	I ususally promote my formula for HE Shells, that the Ref DC is really high near the shell, and the DC drops down with each 5'sq away you are.... an 8die explosion has a DC19 for the 4adjacent squares but the DC is just 15 20' away and it drops to 1die damage at DC12 when you're 35' away. but now I wonder if I need to / should consider the elevated RefDC for the big bangs add to the Quality cost of the gun/shell. Whaddaya think about Harsh Blast Save quality: For each 5 points of DC above 15 for Blast saving throw, count as an additional Quality I of course will be prorating it so +8DC would be 1.6 Qualities in the spreadsheet. This will be raising all the HE MP costs, which in turn will mean all the AP will get more potentant too.... so the big boys, 8"/12"/16" will really have no problem with squishing a 40Hardness tank like a grape.... as it should be. You wanna trade blows with a 8"cannon you better have really thick armor or, and this is important, try not to get hit by a 8" cannon shell
#27 skipsandwich Mar 02, 2009 17:24:09	personally, i'd base any point costs on a value derived from the median DC for any explosion (11 +1/2 dice) since such a value is more representatve of the entirity of the blast, rather then just the epicenter.
#28 backstabbist Mar 02, 2009 18:47:05	Good call. Your right, that should be the way to do it. With that in mind, to reach the 'freebie' DC15 you could have upto a 8die blast.... like ww2 3" guns 16die guns would have median DC 19 and pay 0.8Quality for that extra 4DC.