Toxn

I'm just going to preemptively @Sturgeon, @N-L-M, @LostCosmonaut, @Bronezhilet, @Xoon, @Whatismoo, @Su-57 Flapjack, @A. T. Mahan and @Gripen287. Please add any other past competition participants who I've forgotten to include.

So I got a request recently from {NAME REDACTED} as to whether we have a how-to guide or something for competitions. After a few moments of bitter, bitter laughter at the decade-plus of my life that I've spent cobbling together things that can maybe, sort-of, squint-your-eyes produce a facsimile of a realistic vehicle, I thought I'd share my process: Note: I was half-right - we definitely have supplementary info for aspiring pretend tank designers pinned to this very board. Finally, I'm inviting our forum grognards and past winners to share their process for folk that haven't been here since before the last ice age, so that all can benefit.

Todd's been at it again

We had a short one, along with flour and yeast. Right now the craziest thing is a total ban on cigarettes (been in place since the start) and going in and out of banning sales of alcohol (thankfully I can brew my own just fine).

In other news: I used the lockdown to get proficient at thumb draw, broke all my old bows shooting in the winter, made a new red oak longbow and am now splitting time between it and a cheap compound (turns out that lefties can shoot a right-handed bow using thumb draw).

He and Skallagrim must be on a weight exchange program.

TO: Sen. Chaska Brown, New Capitol Building, cnr Railroad ave and Market str Aberdeen Dakota Union Chas, I've had my boys working on the damn mess that your pet attorney in Sioux Falls sent our way, and they've managed to reconstruct the cartridge. Remember that you owe me one for this, and that RCUAP is getting the manufacturing contract no matter who wins. And if this one wins we're getting all the rights, damn what the will says. We did the family a favour just by naming it. Looking forward to seeing your family in the fall, and my regards to Macha. - Art ------------------------------------------------------------------------------------------------------------------- TO: THE SECOND JOINT COMMITTEE FOR CARTRIDGE DEVELOPMENT, RAPID CITY, DAKOTA UNION Dear Sirs, We have now completed work on the improvements to the cartridge design provided by your attorney, and attach the results hereto. We trust that the improvements we've made to the deceased Mr Taylor's work will earn your consideration for future production contracts regardless of the outcome of your present deliberations, and look forward to your further correspondence in this regard. With kind regards, Arthur Q. Lewis, Director of Production, Rapid City Union Ammunition Plant (Dictated but not read) Encl. Dossier on cartridge design and construction (5 pgs) Summary of test results (7 pgs) Photographic prints of cartridge Blueprints of cartridge, bullet ------------------------------------------------------------------------------------------------------------------- DOSSIER: CARTRIDGE, 0.283 CALIBRE, "FUDD" INTRODUCTION: The new cartridge, developed by the RCUAP, has been provided the provisional name of "Fudd" after the deceased Fudd Taylor, who performed valuable preliminary work on the design. DESIGN AND CONSTRUCTION: Our design combines a low-drag, 122gn monolithic bullet formed from low-hardness drawing steel with a low-cost, lacquered steel case to produce an effective, expedient cartridge for use by our Sioux Scout corps in field operations. The use of lathe-turned drawing steel in the construction of the bullet is expected to reduce barrel wear while retaining a high degree of accuracy. Differential annealing after turning allows for a harder tip, improving penetration of the basic bullet design. A semi-armor piercing bullet is also provided, which makes use of RCUAPs expertise in induction heating technology to case harden the tip. The hardened tip is then quenched while allowing the driving surface to anneal. This results in superior penetration performance against armoured targets and vehicles. Further specialty loads (armour piercing, incendiary, tracer) have also been developed for the cartridge by making use of a deep-drawing steel jacket and a lead plug to adjust the weight of the bullet. This eases the issue of ballistic matching for non-standard loads. The cost of the current design is outstanding, with good penetration and recoil characteristics... -------------------------------------------------------------------------------------------------------------------

TO: THE SECOND JOINT COMMITTEE FOR CARTRIDGE DEVELOPMENT, RAPID CITY, DAKOTA UNION Dear sirs, We are saddened to confirm the death of Fudd 'Bigbore' Taylor, whose body was discovered in an apartment in Sioux Falls last week when we attempted to reach him for comment regarding forthcoming improvements to his recent submission to the committee according to your previous instructions. Here we should note that the circumstances of his death are still being investigated, although the initial police report has the cause of death as "self inflicted from siting (sic) on a big bullet". We will, of course, contact you immediately in this regard should any further relevant information come to light. Regarding your other instructions; we were fortunately able to gather enough of his latest work to recreate the fundamentals of his design, and have sent the same to the Rapid City Union Ammunition Plant ("RCUAP") for further analysis and development. Copies of the photographs and transcripts of the blueprints will be duly sent to you by post, as the original blueprints are unfortunately not in a format suitable for transport by virtue of being written on the apartment walls. Test samples of the projectiles and cartridges developed by Mr Taylor will be delivered to the committee by courier at the earliest possible convenience. Further; given the urgency of the work being undertaken by Mr Taylor on behalf of the Committee, as well as the nature of the agreement entered into by virtue of his submissions to yourselves, we believe that there are no legal impediments to continuing his work while the process of winding up his estate continues. We have accordingly instructed the engineers at the RCUAP on your behalf to begin work on the improvement and finalisation of the design. Here we are given to understand that slight adjustments to the dimensions of the projectile have already been done in accordance with your instructions, and that these adjustments have yielded "a small projected decrease in drag (0.260 G7 BC), along with a small drop in weight (121.7gn)". The plant engineers have further confirmed that they will communicate directly with you on this matter in future. We should note, however, that they have categorically refused to reduce the calibre of the projectile as you requested, with the explanation for the aforesaid refusal being that the spirit of the deceased "invades their collective dreams" whenever they attempt to do so. Given all of the above, we trust that the present matter is finalised for the moment, and accordingly attach our invoice for your further consideration. With kind regards, Chayton Jones Smith, Jones and Wambleeska Sioux Falls Dakota Union

Friends, rejoice! After a long stint at the Dakota Union reeducation camp I have returned. There the evil blackguards who preach the word of small, weak bullets tried to convert me to their blasphemy. But I was too cunning for them - I learned their ways and have returned to turn their secret fires against them! Here is my creation, the shining spawn of my mind. Behold, the 7x48mm FGM2! Although still a bit petite for those amongst us who still follow the true creed of big, girthy, manly-man bullets, it shall serve as a dagger thrust into the heart of the snake that is the second joint committee for cartridge development. For it meets, nay exceeds the requirements of their grotesque mockery of a competition. Now, truly, the scales will fall from the eyes of the people as they are forced to test it and admit its might! And here is the proof: And even at lower velocities, it still almost very nearly juuuuuuuust doesn't make the requirements: And the news only gets better from here! The recoil is low enough even for the atrophied shoulders of the testing committee (10.49 ft-lb). The penetration into pine boards easily exceeds requirements even at the lower velocities (26 pine boards at 600y at the lower test velocity, 29 at the higher velocity). And the cost is fantastically cheap (5.63c) thanks to the use of an annealed, copper-washed mild steel mono-bullet and a lacquered steel case. Truly this is an expedient cartridge that every soldier can take into battle aplenty, to distribute to his foes liberally. And best of all, the use of a long, finely-profiled bullet (OOC note: dimensions taken from here and properly adjusted this time) means that there is plenty of volume for specialty loads (incendiary, armour piercing and so on) that can be ballistically matched to the standard round. My friends, it truly feels good to be able to say this: our great Dakota Union now has a cartridge fit for a man. Edit (OOC note): so I'm a dumb-dumb in more ways than one, and needed a lot of background assistance from @Sturgeon to put together something that actually made requirements (kinda, sorta, almost). So a big thanks to him for taking the time to answer all my questions and provide feedback.

Small boolit too small for wind catch so bal...balleee...bee-see no matter

Having now delved into this issue a bit, the bias of the judging committee becomes clear. They are determined to snuff out the manly, big bore cartridge and replace everything with weak, womanly micro-bullets! Well, two can play at that game. Here is the 5x58mm PoS (Poodle Shooter); a cartridge designed specifically to wound small animals and burn up barrels: We considered other names: the 5x58mm WaNK (Wound and Not Kill), the .197 StFU (Stupid-small, Fast and Useless), the 19-55 Shamebringer and so on. We would be happy to elaborate on these monikers further should the committee so require. The bullet (barely more than a pellet) is turned brass, because we cannot imagine anyone wanting to make the fiddly tooling to jacket it. The case is lacquer-coated steel, so that soldiers can waste ammunition more easily without so much as having to stoop to pick up expensive brass. Proof that it fulfils the despicable requirements of the biased commitee is provided below (OOC note: the BC is based on the Berger 6.5mm 140gn VLD bullet, using 0.307 G7 BC): This includes the lower-velocity requirements: I think we scarcely need to provide proof that such a pathetic round meets the recoil requirements - simply give weapons to women and children and ask them for their opinion (OOC note: 3.8186). Penetration is... uh, acceptable (OOC note: 27 1/2" pine boards, stopping in the 28th at 600y using the lower-velocity test cartridge). Moving on: as to the economy of the round, the calculated value is 8.77 cents. This proves that, even when shooting such microscopic bullets, there is simply no value for money over the venerable M80! Given how expediently we intend our offering to be produced (because we intend to warn our government, not rob it), we cannot imagine that our competitors will do anything more than burn through tax-payer's money in their feckless pursuit of speed over power. A final word: know that we, the designers, have seen through this comical charade and are one step ahead! We have now bought into a barrel making and rifling tooling company, in the expectation of making a fortune on future government contracts for worn-out barrels when this contract is inevitably handed to one of the small-bore "iconoclasts" that litter this great city. In conclusion; we hope that the government of our great Dakota Union soon sees the light and kicks out the charlatans running this rigged competition out. Until then, we offer the 5x58mm PoS as a warning, and a plea to return to a more sensible procurement approach based on the stopping power of big bullets. Edit: so, as @Sturgeon pointed out, I done goofed up with the bullet's BC. When you use something more appropriate, the bullet actually fails on the energy requirement. Which is just more proof of the inferiority of micro bullets! Etc etc.

Boooooooooring

Is this going to be one of those ones where, if you follow the requirements dilligently, you end up with something fast, in the 5-6mm range, shooting a long, skinny bullet? Because I've already specced out a 10mm fat fuck bullet based on an elongated 9x39mm, and I'm going to complain mightily to the board if my MANSTOPPER BIG BORE MAGNUM doesn't get the nod

https://www.popularmechanics.com/military/weapons/a32369359/us-army-mmo-war-thunder/

Knock yourself out.

You build a small shrine to the crewmen of late-war German tanks and then get to work taking the outer suspension units off. Edit: I should say inner suspension units. Taking the outer units off would certainly make it easier though. This is made more complex by the fact that each swing arm actually has hydraulic cabling running through it, so you'd probably want to just run on flats until you can get back to depot and change out there. Sort of the same principle as modern MBTs and their torsion bars - if one breaks the most common thing is just to run on it until you have the option of going back in to have it properly looked at.

A more aesthetic picture of my creation: I'm imagining shitty 90s toy commercial faux-rock playing in the background. Edit: here are some of the vital stats: Length: 26'3" (hull), 41'6" (gun forward) Width: 16'5" Height: 13'2" (top of commander’s cupola) Engine: 3 12-cylinder liquid-cooled turbodiesel, 2,368 ci displacement each, 2520hp total Transmission: hydraulic drive system, 120hp motors on each wheel Suspension: swing-arm, torsion bars/geared torsion bars PWR: 32.1hp/st loaded (note: due to inefficiencies, only around 25-26hp/st makes it to the ground) Ground clearance: 4'2" Max road speed: 56mph Max recommended offroad speed: 22mph Operational range (on road/offroad): 435mi/170mi Base hull thickness: Hull front: 2" sloped at 60' from the vertical Hull sides, rear, bottom, inner compartments: 1.5" Turret front: 5.9" sloped at 20' Turret sides: 1.5" sloped at 20' Mantlet: 6.1" Turret floor, roof: 0.8" Protection (ERA fitted, no fuel, KE/CE): Upper hull front: 12"/>39" RHA equivalent Upper hull sides (30’ arc): 14"/>39" RHA equivalent Upper hull sides (60’ arc): 5.9"/8.7" RHA equivalent Upper hull sides (90’): 4.9"/6.3" RHA equivalent Turret front: 10.6"/12.9" RHA equivalent Turret 30’ arc: 10.2"/29.5" RHA equivalent Turret sides (90’): 4.3"/4.3" RHA equivalent Turret ring diameter: 98.4" Main gun: 120mm L/60 medium-pressure gun Ammunition stowage: 52 rnds complete +22/-6 degree elevation (-12 if not facing forwards). Ammunition: 4.7x34.6" propellant charge (56.7lb max weight) AP (M358): 50.9lb, 3480ft/s, 11.8" RHA penetration at 110yd, 10.6" RHA penetration at 1090yd HEAT-FS (M469): 31lb, 3480ft/s, 15" RHA penetration (reduced charge propellant case) HEAT-FS (advanced): 31lb, 3480ft/s, 17.3" RHA penetration (reduced charge propellant case) HE (M356): 50.3lb (10.25lb fill), 2490ft/s, 1.8" RHA penetration (normal or reduced charge propellant case) APDS (tungsten core): 16.8lb, 4890ft/s, 14.2" RHA penetration at 110yd, 13.8" RHA penetration at 1090yd Secondary weapons: .50 cal coaxial MG (800 rnds) .50 cal loader’s MG (600 rnds) .50 cal commander’s MG (600 rnds)

There's the option to build a wheeled death trap and I'm taking it. Don't worry though - I'm sure I'll get bored in a week's time and try to design a half-track that can do highway speeds or something. Edit: or a 60-tonne convertible drive tank.

Tandem charges are tricky. The Mormon weapon sneaks through from the front (0.63"/16mm residual penetration into the fighting compartment) if shot at a very specific point on the upper hull. However, adding another 1.5"/38mm RHA spaced armour layer midway down the tunnels on either side of the driver (the most vulnerable area of the upper hull front) allows it to defeat the tandem HEAT pretty effectively across the entire 30' aspect. There's also a bit of growth potential in the design - around 9.7st (8.8mt) before the vehicle bumps over the loaded ground pressure requirement, with generous space in the hull front, hull sides, turret interior front and turret exterior sides for NERA. The final thing to note is that the dimensions of this thing are simply hilarious: 26'/2.9" (8m) long without the gun, 41'/6" (12.65m) with, 16'/4.9" (5m) wide and 13'/1.9" (4.01m) high. The Maxcat is house-sized, yet cramped. Edit: the turret is very tricky to work out, as the ERA is arranged at two angles and there's a lot of ways it can get hit. As near as I can tell a shot from the 2"/4" directly from the front and hitting the side panel ERA, turret skirt, air gap and front armour still gets in.

While waiting for the competitors to continue their work, I got bored and decided to produce a design at the other end of the scale: This is the Maxcat, an experimental heavy wheeled AFV which uses a rather insane hydraulic drive system which uses three engines to power the 14 individually-articulating road wheels (each provided with hydraulic motor). The drive system is a power hog, and requires the use of an elaborate hydraulic control system to make it all work. The final wrinkle is that the inner set of wheels need a complex geared torsion bar system to provide the correct amount of travel using stubby torsion bars. The results are impressive, however: the Maxcat sports a 120mm/L60 gun with the same ballistics as the pre-war M58 (including a useful APDS round based on the one used in the old British L1A2), and has impressive survivability thanks to the large distances between the outer hull and the major components. The hull front has respectable KE resistance (260-350mm RHA equivalent depending on the angle and the region targeted) and frankly insane CE resistance (well over 1000mm of RHA equivalent in some places). The turret front is actually less protected over all, but still manages up to 270mm/750mm KE/CE resistance depending on the angle and area hit. The brow armour is also notable, and gets around 300mm/>1000mm KE/CE resistance against attacks from the front. The Maxcat weighs in at just under 70st unloaded, and hits the minimum range requirement by dint of six massive fuel tanks with a maximum capacity of just over 1150 gal. It hits 90km/h on roads, and will try to do the same offroad if the driver is foolish enough to open the throttle. With all of the above, the Maxcat is designed to be an MBT in all but name - meant to take on all comers head-on and win. It would probably be an expensive, resource-devouring maintenance queen at base, but while out in the field it would be an unholy terror to anything foolish enough to get in its way.

Agreed. It would peel off HHS plates, but leave the base armour relatively unmolested.

I think it depends on whether it's the original version (probably the version current for this competition) or the hypothetical up-armoured ones, and whether you're talking frontal arc or a side shot. A quick look at the original submission shows 200mm LOS RHA, an air gap and 60mm LOS HHA. So around 350mm RHA penetration equivalent should do it. This equates to about a 100mm HEAT-FS or a really, really beefy gun firing AP. Like, significantly more potent than the M58. Given the limits of APFSDS in this competition, you'd probably be looking at something in at least the 125mm range if that's what you want to sling. For side shots you're looking at something like 160mm RHA equivalent penetration to get into the turret, which puts you in the realm of super-hot 75s and the 90mm M3

The design was originally based on Unimog components (although everything except the tires has been changed at this point) and a moggie is an unremarkable cat...

Greetings all, I've been pulled on as a judge for this one, so none of the following should be construed as competition so much as... encouragement. This is the Mogcat: It's designed to exactly nail the minimum specs, while being relatively easy to produce and long-legged. It sports a 3"/76mm main gun, a bunch of machineguns and the sort of conveniences you'd expect from a late-40s design (gunner's panoramic sight, wet ammo racks, internal firefighting equipment and smoke launchers). It's otherwise very bare-bones, and comes in at all of 10.3st/9.3mt. I'll add further specs as this goes along, but for the moment all you have to know is that this is the minimum, lowest bar that I can think of. This thing is intended to be the product of unimaginative minds working at what passes for the ordinance department in the Lone Free State - men who spent their lives designing incremental improvements on machineguns and recoilless guns, and think that their lightweight 3" gun is a world-beating novelty. For what it's worth; what I would like to see is something that grabs the requirements by the balls and works out a way to wring something that can beat @N-L-M's Norman design in a reasonably fair fight out of the thin gruel that the Provisional Government has put out. Remember that the Texans don't know what they don't know - their official line is that the arrival of Deseret light tanks is some sort of shocking revelation. But they aren't stupid - the smarter engineers will already be looking at what they could do with their given automotive and gun tech, and what was achieved in the pre-war era, and are probably staying up late at night worrying about their conclusions. Update 1: I had a think last night, and decided to swap out the turret crew to a commander-loader and gunner configuration instead of the T-34-esque commander-gunner and loader configuration (now included with the rest of the pictures). Here's a bonus picture of the vehicle in travel configuration - turret rearward and gun in cradle: Update 2: Here's some more stats on the vehicle, in the prescribed units... Description The Mogcat is a 6x6 armoured scout car designed for mobility and extended operations. The design boasts an innovative engine, drivetrain, suspension package and gun, all built with an eye to ruggedness and light weight. The Mogcat's 3-inch cannon is able to provide useful anti-armour (APHE and HEAT-FS) and anti-infantry (HE, canister and shrapnel shell) firepower, while the plethora of machineguns it sports allows it to tackle dismounted infantry and light vehicles with confidence. The combination of purpose-built drivetrain components, long operational range and firepower makes the Mogcat a strong contender for the present production contract. Major dimensions and mass Crew: 3 (driver, commander-loader, gunner) Length: 16'/9" (hull), 19"/4' (gun forward) Width: 6'/7"m Height: 9'/6"m (top of commander’s cupola) Unloaded weight: 8.7 ton Loaded weight: 10.3 ton Ground pressure: 4900lb/ft2 (unloaded, muddy ground) to 5785lb/ft2 (loaded, muddy ground) Axle loading: 3.4t/axle loaded Mobility Engine: 4-cylinder turbodiesel, 732cu displacement, 200-280HP PWR: 19.4HP/t loaded, detuned Ground clearance: 17.7" Max road speed: 60mph Max offroad speed: 20mph Operational range (on road/offroad): 850mi/500mi Protection Armour: 2" LOS on hull front (1" RHA @ 60°) 0.8" LOS on hull sides with 30° angle (0.8" RHA @ 90°, 0.5"mm @ 45°) 0.6" RHA on hull rear 0.5" LOS on hull bottom (0.4" RHA @ 45°) 2" LOS on turret front (1.8" RHA @ 30°) 2" CHA mantlet 0.8" LOS on turret sides with 30° angle (0.6" RHA @ 25°) 0.6" RHA on turret rear 0.4" RHA on roof 0.4" RHA on turret floor 2" RHA turret neck ring and splash guard 0.4" Aluminium turret basket, skeletonised 3.2" smoke dischargers (2 reloads). Fuel tanks on driver’s sides improve protection against threats from the front. Ammunition stowage in wet racks in turret bustle, turret floor and driver’s compartment. Internal fire control system (BCF canisters in engine compartment and fighting compartment, driver has access to removable CO2 extinguisher). Firepower Turret ring diameter: 4'/5" Main gun: 3" L/40 medium-pressure gun, 12" recoil travel Ammunition stowage: 50 rounds main gun ammunition stowage +30/-10 degree elevation. Ammunition: 3"x15.2" cartridge (3.7" base, 19lb max all-up weight) APHE: 13.9lb, 2425ft/s, 3.5" RHA penetration at 1000m HEAT-FS: 15.4lb, 2295ft/s, 9.8" penetration HE: 13.7lb (1.35lb fill), 2460ft/s, 0.4" RHA penetration APFSDS (spindle-type, 15L/D ratio, maraging steel penetrator): 1.5lb, 5900ft/s, 6.5" RHA penetration at 1000 yards. Secondary weapons: .30 cal coaxial MG (600 rnds) .30 cal gunner's MG (600 rnds) .50 cal commander’s MG (500 rnds) Additional features Long-range transistor radio. Vehicle intercom system. Ancillaries (fire tables, gunner’s quadrant, traverse markings etc) for indirect fire missions. Commander has access to panoramic sight (x1) and telescopic sight (x4) for target acquisition and lay-on. Turret traverse is electric (30 degrees per second rotation). Fume extractor on main gun Large hatches in hull rear allow easy servicing of engine and gearbox. Storage lockers in hull rear flanking the engine for personal/supplies stowage. Hydraulic jacks on the hull bottom between the first and second wheels and at the rear make changing tires easier. Update 3: I reworked all the images.

Thanks. What are the dimensions on the 16.0R20 tires, just so I can double-check my math? Edit: the tires I used are 345/80R20s, which have a total diameter of just over a metre and are 34cm wide.