Just offhand, I think that Old Moses vs M113 would produce only a medium-sized dent.

I agree, I don't think a 6-pounder ball propelled by blackpowder will have enough energy to penetrate the aluminium armour of the M113 - but will surely scare the living daylights out of anyone inside when it hits! :D

If you can score a hit on the tracks though you might achieve a mobility kill?

The armor on the 113 is a lot tougher than most give it credit for.

BONNNNGGGG!!

Have a feeling it would scare the living hell out of anyone and make them back off until they figure out what the heck just hit them

What about an arrow? APFSDS but black powder powered. :D

Well... maybe? But I'm thinking there still would not be enough energy for the projectile to do any real damage. I can imagine it getting embedded in the armour but not actually getting all the way through and still be capable of causing damage to the internals.

When I first joined the Aussie Army Reserve, my first unit was Armoured Recce (using the M113). The entrance to the vehicle compound had a crew door (from the rear ramp) mounted to the left of the gate. It had been damaged at some point and written off so somebody decided to take it to the range and test it against the small arms we were issued.

Specifically 9x19mm, 5.56mm, 7.62x51mm but as I recall it, only the 7.62 had the energy to penetrate and that was I believe at reasonably close range (somewhere below 300m). So based on that very hazy recollection, I figure you're going to need to get that arrow up to at least 850 m/s (2,800 ft/s) muzzle velocity with at least 3,470 J (2,559 ft⋅lbf) of energy. Black powder is a low explosive, is it going to generate enough force to give any projectile those levels of velocity and energy?

This is interesting, back about twenty years or so now, we had a chance to do a live fire (mock assault breach) with war stock (AP, API and such) for my unit and most of the hard targets we got to shoot at were old M901's. After it was done we were had to go and police up the range where we had been, this gave us time to look at the vehicles. I do not know how long they had been out there, but do know that there was a British unit that went before us (their warriors were just leaving as we showed up). When we looked at the vehicles there was no penetrations that I or anyone I talked with saw. We were using M16A4, M249, M240, and M2HB's. I do not know what the warriors used but as they did not penetrate (we were guessing that the VERY LARGE dents were from their TP ammo) that it was not AP, and no HE was allowed on the range so know it was not that. This makes me wounder, we only shot the sides, my guess was that the front/back would be at least as tough (the door that I know is not solid) looked at least as much. But is it, or did they make changes to the metal of the armor as time went on, so one from 1960 is not a tough as one from 1970? I do not know, but makes me think as you could penetrate with things that we could not.

In an effort to refresh my hazy recollections, I spoke to one of the guys I joined the unit with and yes the passage of time does dull my memory far too much!
The inside section of the door was facing outwards, as in, the inner section was shot up. I believe the inner part of the door is steel and not the aluminium alloy armour plate of the outer hull. Wish I had taken a damned photograph of it now.
I thought it was the outer section but my mate has said it was the inner section - his recollection makes more sense.

Plus, they didn't just shoot it with 7.62x51, they also gunned it up with the .30cal L3 MGs (British version of the Browning M1919) that are normal armament on our M113A1) so what I thought were 7.62NATO holes are just as likely to have been .30-06. Not that that makes any difference in regard to the armour plate which a web search states for the M113A3, the armour can withstand up to 14.5mm (although I don't think there's that much difference between the armour on the A1 and the A3.)
He's pretty sure there were no penetrations of the outer section.

Note:
For anyone not familiar with the M113, the crew door in the rear ramp is a two piece affair with the outer section made of armour plate and the inner section made to withstand troopies pounding on it has they disembark when the ramp is down.
This photo from Vietnam shows what I mean.
https://i.pinimg.com/736x/04/87/90/0...tary-units.jpg

The simple answer is no, it's not going to get up to the required speed. https://www.practicalmachinist.com/v...powder-325903/

EX-41 Launcher
 

The EX 41 grenade launcher, also called the Shoulder-Fired Weapon (SFW), was a prototype multi-shot grenade launcher that was never adopted by the United States military. nstead of the standard low-velocity 40×46mm grenade used by the M203 and M79 grenade launchers or the standard high-velocity 40×53mm grenade used by the Mk 19, the EX 41 used a hybrid of the two developed by Indiana Ordnance.

https://en.wikipedia.org/wiki/EX_41_grenade_launcher

http://www.fbodaily.com/cbd/archive/...5/55sol001.htm


https://www.youtube.com/watch?v=dmoKSwtbJlg

A case of taking two old weapons systems and mashing them together was the Yugoslavian SO-122. In the 1950s, Yugoslavia received 599 M4A3E4 and 1 M4A3E8 (which makes page 39 of the Soviet Combat Vehicle Handbook hilarious in hindsight). In 1956, they began looking at how to replace the 76mm gun, which was rapidly becoming obsolescent. Their solution was a number of M1931 (A-19) cannon that Yugoslavian partisans had captured from German forces during WW2 (which had in turn captured the guns during the invasion of the Soviet Union). They built a new turret and shoehorned the same 122mm gun used on the IS-2 and IS-3 heavy tanks into a Sherman. The prototype also replaced the M4's engine with the engine from the T-34-85, but this was not planned for production models in order to keep the conversion quick.

The prototype was ready by 1965. Its weight had increased to 33.5 tons, but the overall performance was similar - acceleration had dropped slightly, maximum speed increased slightly to 50 km/h, and fuel consumption was roughly halved by using the V-2R engine. 100 of these were supposed to be built, but the retirement of the M4 hull in 1966 put an end to those plans.

The SO-122 in-game:
Use the M4A3E8 on page 39 of the Soviet Combat Vehicle Handbook. Replace the 76mm with the following:

122mm A-19 (Rng 400 for all shells)
AP Dam 27, Pen 55/47/40/26
HVAP Dam 27, Pen 71/62/52/34
HE C:15 B:27, Pen 11C
HEAT C:10 B:22, Pen 42C

Ammo load should probably be around 40 shells. The tank appears to have kept both internal machine gun mounts, though they would likely have taken something like a PK/PKT rather than the M1919A4.

With their lack of armor and big, slow-firing gun (Rld 1), this falls into the "eggshell with a sledgehammer" category of armored vehicles. Working as a tank destroyer from ambush would likely be their best strategy.

When a Nock Gun just isn't enough volleying for you:

https://www.forgottenweapons.com/per...rel-flintlock/

And from the same museum in Liege, there's this interesting piece: -
https://www.grandcurtius.be/en/museu...rimposed-loads

The museum website has some information Ian didn't cover (most notably barrel length), so here's a rough guesstimate at the 14-barrel rifle's stats:

7.5x30mm Conical Black Powder
Mass 6.09 kg
Magazine 2(14), Rld 2 per barrel (14 per lock, 28 total), Dam 1, Pen Nil, Bulk 6, ROF 7, Recoil 2, Range 50

The weight of 14 barrels plus 2 locks plus 1 stock plus ammunition comes to 24.4 kilograms, but I divided it by 4 to get something closer to how the gun's mass appears when Ian handled it. Range is maximized at 52 meters if it's a 31mm black powder charge, but I rounded both because I could. I used a conical round rather than ball because of the polygonal rifling. It's not very powerful, but it is intimidating.



The Chambers machine gun is terrifying because of the potential for flashback detonating multiple rounds at once.

Abrams TTB
 

Has anyone had any thoughts about the Abrams TTB (Tank Test Bed) demonstrator and how it might have developed into an operational vehicle?
It seems GDW might have used the TTB and how it would be as a production vehicle with their Abrams "Giraffe" (which is essentially a refined version of the concept).

I haven't seen much online about the TTB but as it was a demonstrator, it's not like it had a huge presence anyway.
Here's a few pages about it: -
https://tankandafvnews.com/2016/03/1...-future-tanks/
http://warfaretech.blogspot.com/2015...-unmanned.html
https://soapbox.manywords.press/2017/11/29/m1-ttb/
https://www.steelbeasts.com/topic/10...ttb-and-cattb/

Airfox
 

Aircraft don't make it into most T2k campaigns, and Romania probably isn't a setting many (if any) most ref's/players have any experience using, but here's an attack helicopter that almost was.

http://www.aviastar.org/helicopters_eng/iar-317.php

It's featured in Modern Fighting Helicopters by Gunston & Spick (1988)- they thought it was a promising platform that would see a lot of interest/orders from developing nations, given its price-point and tried-and-true engine (it's based on the Alouette III) but, after the Romanian revolution, the project was cancelled. AFAIK, only a couple of prototype/demonstrators were built.

I'll call your bluff and raise you the Cheyene... Now updated and appearing as the RAIDER X!

https://youtu.be/fR-r6RR1nJM

https://youtu.be/LpQC_qpkRRE

A mix-and-match firearm this time, the LeMat Carbine. Yes, the carbine, not the revolver. Well, sort of the revolver...it's complicated.

You see, Doctor Colonel Jean Alexandre LeMat wanted to produce long arms in addition to his 9-shot revolvers with shotgun goodness in the center. So he produced 9-shot revolving carbines with either shotgun or rifle goodness in the center. Around 200 of these were made, and the handful of survivors vary in caliber for both the central barrel and the surrounding revolver. All have 20" barrels and I estimate the weight at 4.5 kilograms (seriously, if anyone can find an actual weight, I'd appreciate it, because Google is failing me on that point of research).

Revolver options:
Original (10.668x47mmBP Conical)
Dam 2, Pen Nil, Ammo 9i, ROF SAR, Bulk 6, SS 1, Rng 74
Pinfire (11mm French Ordnance)
Dam 2, Pen Nil, Ammo 9R, ROF SAR, Bulk 6, SS 1, Rng 59

Center options:
.56 rifled (14.224x31mmBP Conical)
Dam 3, Pen Nil, Ammo 1i, ROF SAR, Bulk 6, SS 3, Rng 98
.58 rifled (14.732x31mmBP Conical)
Dam 3, Pen Nil, Ammo 1i, ROF SAR, Bulk 6, SS 3, Rng 102
20 gauge shotgun
Dam 9 (close)/1x11 (medium), Pen Nil, Ammo 1i, ROF SAR, Bulk 6, SS 1, Rng 12

The powder charge is probably a little high for the original revolver load (it's roughly 63 grains), but I was trying to maximize range. The .56 rifled is a 74 grain load and .58 rifled is a 79 grain load. Again, they were calculated to maximize range using FF&S.

The 9i for reload on the first option is because it's a lead bullet loaded over loose powder, so it's slower to reload than the self-contained pinfire cartridges. The shotgun range I'm not 100% sure on, because I'm terrible at using FF&S to generate shotgun stats. For the shotgun beyond close range, treat it as a 5-round burst and two 3-round bursts.

While the carbine was apparently made into the centerfire era, I haven't seen any records of what calibers were manufactured, and I'm not sure any of them are among the 18 known survivors.

I know you do good work... but these formulas in FF&S and WTG are STILL driving me crazy. Here are weapons with a fairly low sectional density and TERRIBLE Ballistic Coefficient being driven by [low velocity] BLACK POWDER to boot. Yet when I even run the formulas you get SHORT RANGES around a hundred meters in a game where high-velocity smokeless powder loads with excellent Ballistic Coefficients are hitting 75m to 80m max. The Range formula seems off by at least 1/3 too much. I noticed this in your entries on the Primitive Weapons Thread too. I think the Forum needs to brainstorm the modification of those formulas.

On my quest to make the perfect Twilight 2000 Sheridan I think I've finally found it.

Believe it or not but way back in 1967 there was already concerns that the M81 (as it was then) Gun/Launcher may not be a good idea. As such Rock Island Arsenal did a crash program of four other weapon systems to fit in the M551 turret should the M81 develop problems.

Of the four only two were recommended mainly due to space problems, although it was mentioned that if serious redesign work was done all four would fit in the turret. The two weapon systems were:

- M32 76mm Cannon, the same as was on the M41 Walker Bulldog
- XM180 105mm Gun/Howitzer from the XM104 super mobile lightweight howitzer (which really should have gone into service)

Of the two the XM180 was the preferred weapon system as it coupled low pressure and trunnion loading with high damage output and ammunition that was still largely in service.
This weapon fired much faster than the existing M81 because it didn't need a compressed air purge to blow out the bore so the combustible cartridge cases wouldn't ignite prematurely. It's likely that by the time of the Twilight War an A1 version of the gun/howitzer would have been developed with a bore evacuator for even faster firing. Notably the XM108 could fire any 105mm howitzer ammunition in US stocks and new racks for the vehicle gave a stowage of 50 Rounds. (I note the UK ammo has a squash head round)

If the M551A1 is the M81-armed standard version with vision upgrades and a minor modernisation package that would make the M32 76mm the M551A2A1 and the XM108 105mm the M551A3A1

Here's an image of the gun way back in 1967
https://i.redd.it/gznrgk1x00w31.jpg

Raison d'etre
 

That's an interesting concept, Chalk. The XM180 would make a great light assault gun for MOUT*, but it kind of loses the Sheridan's raison d'etre as an AT-capable light tank for Airborne forces.

Was there ever an AT round developed for 105mm howitzers? Something that could be used when the SHTF?

*And with "Beehive" rounds, it would be deadly against infantry in the open.

Seem to recall the M101 howitzer having a HEAT round. While not a sabot round, it can have a decent punch if used in the correct way.

I think the problem is with smokeless more than BP. The Springfield Model 1855 rifle-musket was noted to be effective to 500 meters and deadly to 1 kilometer, firing 14.7x23.5mm BP Conical (.58 with 60 grains of powder) from a 101.6 cm barrel. Arguably the range should be around 125 so that it has 125/250/500/1000 as its range bands, using long as effective range and extreme as the range at which it can (with major luck) inflict casualties. Actual calculated range is 89, which is 28.8% low. I know from tests a while back that the formulas really have problems with the Whitworth, which hit targets at 1.8 kilometers in trials.

The GDW rules also don't have a good way to simulate the trajectory problems of black powder that required better range estimation than with high-velocity small-caliber smokeless powder. Black powder rifles had plenty of accurate range, but they needed accurate range estimation to be of any use, and that's something that could probably use a house rule.

I think the problem for the LeMat specifically is that I went for the powder charge that maximized range, which is almost certainly heavier than what was used, since the .58 BP exceeds the service charge for the rifle-musket. I don't know what charges were actually used, and lighter charges would reduce range.

(A lot of this is cut-and-pasted from the FB page)

Importantly this whole process was reversible. You could swap guns and racks in a few hours.

The way I see this thing going down is that the ammo for the M81E1 is going to get used up and they simply don't make it anymore. At that point these weapons and racks are shipped out to divisional workshops and the systems swapped over. M81E1s in still good condition are shipped back up the chain to where the few remaining M551 units are that are near supply chains that have the ammo as spares.
Yes, it does lose tank-killing ability but hey, TOWs are everywhere. If the crew really want to go tank hunting they can keep a MILAN in the bustle rack :)

Otherwise they have two jobs; the first is skirmishing with other recon assets. Now the flyboys and the satellites are gone it's back to going-out-and-having-a-look. This means you'll be meeting PT-76s (which, as I posted earlier on a long micro-essay, isn't actually a scout vehicle but something entirely else), BRDMs and the odd BMP.
The second is infantry support. Unlike IFVs the big honking gun can drop entire buildings and break open bunkers. They were actually used like this in Panama.

The "beehive" rounds were the famous APERS-T. It was used extensively in Vietnam in anything that used a low recoil barrel.
It's been replaced with a special airbust setting on the various fuzes that lets you use standard shells, this is the mechanical time–super quick (MTSQ) fuze. With this you can set the shell to blast nearby targets but it also gets those in trenches, crawling or otherwise in cover.
Who'd be an infantryman?
I'd still put one or two APERS-Ts in the rack if I had a chance for targets of opportunity.

Elsewhere we've done some discussion on what the range and rate of fire would be.
Now, obviously the default information for this would be Paul's standard NATO 105mm howitzer. However I don't know which gun Paul based this on, and if it was a semi-automatic breech as is on the XM180 mentioned or the manual interrupted screw on the M103 105 mm Howitzer off the M108 (they tried to fit this originally and it would have meant moving traverse gear, something they didn't want to do). Also howitzer fire rates are based on "sustained fire" shooting, whereas direct fire rates are usually much higher as you're essentially in a shit-has-hit-the-fan situation. I'm not sure what if the direct fire range listed in Paul's rules are the same as something with a dinky little barrel like the XM180. I'll leave that answer for the specialist cannon-cockers here.

I believe there were only three different weapons tested. Two of the four were the M32 76mm, one with the M76 recoil system (from the M41) and the other using an adapted M81E12 recoil system (from the M551).

Assuming the XM180 uses the same ammunition as the M101 howitzer, the M327 HESH/HEP round would be available, with an 80% chance of spalling 5 inches of armor at 60 degrees obliquity. If any M67 HEAT was still around, it would also be usable, but IIRC it was replaced by the M327 pretty quickly in the late 50s.

Another benefit of Beehive rounds is that because they don't use HE, they are often quite effective for creating entry points into buildings or through walls (without the risk of explosive throwing its blast or debris back onto the vehicle or accompanying troops).

Yeah, the 76mm was tested twice; once with it's own recoil system and once with the M81 recoil system.

I've recalculated the numbers for the LeMat using best guesstimates of powder charges. The decimal measurements are caliber and grains of powder (i.e. .42-16 is a .42" ball and 16 grains of powder). The shotgun has two statlines for ball and for shot.

The 60 grain load for the .56 is the midpoint of what was used in Civil War carbines (Merrill's used 50 grains, Colt's 60 grains, and Burnside's 75 grains), while the 75 grain load for the .58 matches the rifle-musket. Barrel lengths are 19.687" (50cm) for the revolver and 17.375" (44.1325cm) for the center.

Pinfire and centerfire carbines would tend to have the shotgun barrel, while the muzzle-loader might have any of the center barrels. The 9R calibers will still be slow to load, since they require single ejection of spent cases with a non-spring-loaded punch and single loading of new rounds through a gate.

LeMat Carbine
Revolver loads
.42-16 (10.668x12mmBP Ball)
Dam 1, Pen Nil, Ammo 9i, ROF SAR, Bulk 6, SS 1, Rng 35
12mm Perrin Pinfire (12x15mmR BP Conical)
Dam 2, Pen Nil, Ammo 9R, ROF SAR, Bulk 6, SS 1, Range 62
11mm French Ordnance Centerfire (11.47x17mm BP Conical)
Dam 2, Pen Nil, Ammo 9R, ROF SAR, Bulk 6, SS 1, Range 63

Center barrel loads
.56-60 Rifled (14.224x25.2mmBP Conical)
Dam 2, Pen Nil, Ammo 1i, ROF SAR, Bulk 6, SS 2, Rng 87
.58-75 Rifled (14.732x29.35mmBP Conical)
Dam 3, Pen Nil, Ammo 1i, ROF SAR, Bulk 6, SS 2, Rng 81
20-gauge slug (15.75x13.7mmBP Ball)
Dam 2, Pen Nil, Ammo 1i, ROF SAR, Bulk 6, SS 1, Rng 23
20-gauge shot
Dam 11 (close)/1x15 (medium), Pen Nil, Ammo 1i, ROF SAR, Bulk 6, SS 1, Rng 12

GDW went with what is termed "practical accuracy" which is what the average shooter could pull off "in the field." What you are modeling would be called "mechanical accuracy" or "benchrested accuracy" for expert shooter or shooters using controlled conditions. My issue with changing the four range band model of RAW is that you will break the practical accuracy of both pistols and SMGs if you change the formula to properly address the maximum "mechanical" or benchrested range of rifles using the four range bands.

I agree with you that GDW needed to take into account the effective long-ranged accuracy but I think they just needed to add one more Range Band. The Maximum Effective Range band. This would allow those spectacular shots that are legendary today. I also agree with optics, bipods, and tripods adding to the Base Range. I just think they didn't go far enough with scopes. Why do I add another Range Band? Just look at what happens with the M16A2

Short Range = 55m, Snap Shot: Average (Skill), Aimed Shot: Easy (Skillx2)
Medium Range = 110m, Snap Shot: Difficult (1/2Skill), Aimed Shot: Average
Long Range = 220m, Snap Shot: Formidible (1/4Skill), Aimed Shot: Difficult
Extreme Range = 440m, Snap Shot: Impossible (1/10Skill), Aimed Shot: Formidable

And finally my Maximum Effective Range...
Maximum Effective Range = 880m, Snap Shot: NO, Aimed Shot: Impossible

This allows that impressive one in a million shooter WITHOUT compromising the fairly accurate practical accuracy in the RAW game. It also allows for the positive effects of things like optics and bipods with an easy to apply mechanical advantage by simply adding range.