Yup

In real life the 5cm KwK 38 cannot penetrate the frontal armor of the Infantry Tank Mk.IIA, aka Matilda II (A12).

The GURPS: WW2 book All The King's Men gives DR 300 for that frontal armor on the hull and 290 on the turret.

The 5cm PzGr 39 the Germans were using in Libya does 6dx6(2) pi++ with a linked 1d-3[2d+2] cr ex.

That will roll an average of 126 which will fail to penetrate the 145 DR the turret front is reduced to by the armor divisor.

This GURPS!

Likewise the QF 2-pdr on the Matilda worked against the Pzkw III Ausf G's DR 120 hul and DR 145 turret front.

The best 2-pdr round in the desert was the Shot APCBC/T Mk.I which does 6dx4(2) pi++ and averages a roll of 84 which should punch DR 168...  I say "best" but all of the AP rounds calculate to 6dx4(2) pi++ except the early AP/T Mk.IT which is what GURPS calls an SAPHE round doing 6dx6 pi++ linked 2d+1[2d] cr ex; that only punches 126 DR, barely adequate for the Ausf G.

The H has DR 230 in the front and rear and some of the G's were upgraded to the H standard by the Afrika Korps.

This GURPS!

Well It's Official Anyway

For the most part, Gun Stats is giving me stats that are very close to the numbers I pulled out of my ass by comparing the gun I was making to a gun that was already published.

At least these new numbers have the sanctity of being created by an official publication.

One interesting change has been the FG.42.  Several sources say the Luftwaffe issued the steel-core S.m.K round, which is armor piercing.

That changes the, calculated, damage from 6d+2 pi with the s.S round to 4d+2(2) pi-.

The average hit from s.S will deal 23 points of damage.

S.m.K will roll 16 on average, but that will punch DR 32.  That's better than s.S, but the pi- means that anything that gets past the armor will be halved.  So it does just 8 points on an unarmored target; about a third what normal ball does! 

It Doesn't Seem Right

Doing the Gun Stats for the Royal Ordnance Quick-Fire 20-pounder.

I'm getting the penetration numbers I expected, but not the ranges.

I am accustomed to sabot rounds outranging the full-bore rounds.

This is not true for APDS vs AP.

APDS Mk.1 gets 6dx19(2) pi++ to 5,000/24,800.

Shot Mk. 1 an APCBC (AP in GURPS) gets 6dx11(2) pi++ to 11,600/38,000.

So I dug into it.  Turns out it's correct.  I did not expect that.

It repeats with the 105mm L7/M68 gun.

M392 APDS has a range of 4,300/19,000.  M456 HEAT has 7,900/23,200.

"Normalcy" is restored when I did the M735 APFSDS round and got 11,500/34,000 for range. 

It makes sense.  The penetrator on an APDS round is relatively short and it's very light compared to the full-bore rounds.  It has a poor ballistic coefficient, more drag means less range. 

ARGH

What kind of round is a 106mm M-DN11 HEAP for the M40 family of recoilless rifles in GURPS terms?

The 106 mm HEAP M-DN 11 is a fixed round with the projectile rigidly secured to the perforated steel cartridge case by a crimping groove. The projectile has two indexing buttons 180º apart on the forward bourrelet and a pre-engraved copper drive band encircles the projectile just forward of the base. The projectile is a thin-walled aluminium shell with a conical ogive, filled with 770 g of hexogen with 5 per cent wax. The internal surfaces of the shell body are lined with 1,000 steel pellets set in resin. A nose-mounted M-DN 121 fuze may be preset for either instant impact functioning or delayed action. In either instance the usual blast effects are enhanced by the scattering of the 1,000 steel pellets. The perforated steel cartridge case may either be M93B1 or M94B1, both with an M57 percussion primer press fitted to the base. The propelling charge is 3.65 kg of M26 propellant powder in multiperforated cylindrical grain form, known in Spain as Fil 349. This round has a maximum effective range of 1,500 m, although the maximum range possible is 7,640 m. Muzzle velocity is 560 m/s. This 106 mm (actual calibre 105 mm) recoilless rifle HEAP round is produced in Spain by SANTA BARBARA SA and DEFEX SA. It is primarily intended for anti-matériel or anti-personnel use and contains 1,000 steel pellets.

 

That sounds like a normal, everyday, HE round with the pellets added to make up for the thin skin of a recoilless round. 

7.62x51mm Purple Tip

Japan decided that full up 7.62 NATO was too powerful for its purposes, but also wanted to remain ammo compatible with US forces.

So they made a 7.62x51mm NATO rifle and issued a reduced pressure load to its troops.

For years I didn't have much information on it.

The internet has grown since then.

It's a 139gr bullet at 2,300 fps from the same barrel length as a H&K G3.

The G3 sends a 146gr bullet downrange at 2,625 fps.

The Japanese round, according to Gun Stats will do 5d+2 pi out to 700/2,900.  The G3 does 6d+2 pi to 840/3,500 (High Tech says 850/3,750) and so does the Type 64 firing NATO spec ammo!

The Type 62 GPMG, with a longer barrel will do 6d pi out to 730/3,100 and 7d pi to 900/3,800 with NATO spec ammo.  That 900/3,800 is the same as what the M14 calculates to, but High Tech says should be 1,000/4,200; plan accordingly.

Why did I figure this out?

I made something of a 'verse hopping setting and the players start as tourists at Ayer's Rock Urulu in Australia when the Japanese invade in 1994 inspired by Tom Clancy's Debt of Honor.

I knew the Type 64 rifle fired a reduced power round, but didn't know things like bullet weight and velocity so I made some shit up and called it good when the players captured a couple guns.

Ever since then, I periodically check up to see if more information has escaped the relentlessly classified JSDF records.  It's this kind of secrecy that had the Japanese using the Type 64 in 1994 instead of the 5.56 Type 89!

Anomaly

I'm still wrestling with Gun Stats and round nose bullets.

.30 M1903 uses a 220gr, 1.308" long bullet fired at 2,300 fps.

.30 M1906 uses a 152gr, 1.123" long bullet fired at 2,700 fps.

1903's ranges are 1,240/5,200.

1906's ranges are 890/3,700.

Longer bullets do tend to hold velocity better and, thus, go farther.

The advantage of the lighter, faster, spitzer rounds was supposed to be the flatter trajectory not extended range.  This should show in the Accuracy column.

But it doesn't because of the length to diameter ratio of the longer bullet getting a +1 and the relative velocities being in the same bracket. 

.30-06 does have a lower ST and Recoil with 9 and 3 versus 10 and 4, making it easier to shoot.

I don't think, as a whole, this passes the reality test. 

Penetration

Sometimes it seems like a given round is underperforming in GURPS.

But it's a game, not a simulation...

For example, the WW2 M82 APC (APEX in GURPS terms) does 6dx10(2) pi++ with a linked 6d+2[4d+2] cr ex.

That was calculated from a formula that gives all six dice their average value of 3.5 to, mostly, match the muzzle penetration value against rolled homogeneous armor.

Thus that round will penetrate DR 420 or rolling a 21 on six dice or ((6x3.5)x10)x2.  Dr 420 is 6" (152.4mm) of RHA.

But you could roll a 6 on six dice, do 60 damage and penetrate 120 DR or 1.7" or 43.5mm.

OR you could roll a 36 on six dice and do 360 damage and penetrate 720 DR or 10.3" or 261.3mm. 

Officially it penetrates 143mm or 5.6" or DR 393 or 6dx9(2) pi++.  At the muzzle.

Gun Stats gives it a little extra performance.

Realistically, that 393 points of damage should be at the muzzle and it should get smaller as the range increases.

But you can roll all ones for 6x10 at 1 yard and all sixes for 36x10 at 6,660 yards.

Again, game.

Balance between playable and accurate.

It's hard to strike sometimes.

The randomness of the dice and the chance at unrealistic results allows the game to account for anecdotal stories where people went, "Did you see that shit?"

A DR 4 M1 helmet will not stop even the minimum damage of a 7d pi K.98k, but there's examples where the round bounced off.  Result of a miss by two?  A miss by one is a torso hit (ever notice that all misses by 1 go low not high?)  The GM has to provide narration to what's going on to the players.

There's examples of "no way that will penetrate" going right on through.

Things tend to GURPS.  It's what I like about the game.

I don't wanna have to do the math that calculates the impact angle against the angle of the armor's slope and the velocity at that EXACT range.

Dice will suffice. 

Gaming The System

The feint rules in GURPS are pretty simple.

There's a quick contest of weapon/defense skill rolls and margin of success is the penalty to their defense next round.   See p.B365.

It doesn't get used much because, most of the time, the players are overpowering their opponents and they don't need the bonus to land hits.

But something I noticed a while back was when you announce that you're feinting, the opponent goes all-out-attack that same turn.

They KNOW they don't need to defend that round, because a feint isn't an actual attack, and they get a +4 to hit.  If they hit, the penalty from wounding the character doing the feint more that offsets the risk of a penalty to their defense next round.

That seems unclear to ME as I write it.

Turn 1:

NPC feints at Player.  Contest gets a -3 to the NPC's defense in turn 2.
Player all out attack (determined) the NPC scores 3 points of damage.

Turn 2:

NPC suffers effects of injuries, -3 to hit.  Misses.
Player has defenses again, at -3, but that doesn't matter because the NPC missed.

Thus nobody feints!

At least not when they have the initiative and move first.

If you go after the Player, then they have to decide to use all out attack BEFORE you announce your feint.

So to make this work, you have to take a wait maneuver to let them attack first.

If you've got good active defenses, like il Gatto, then this is a good plan. 

PS: Suddenly a lot of cinematic and SCA fights I've seen make more sense in gaming terms.  If there are numerous wait and feint maneuvers going on, that explains the circling each other slinging soliloquies! 

GURPS ALL THE GUNS!

 With nothing else to do...

I took Gun Stats at the guns in this video.

GURPS: SEALs in Vietnam had the 5"/38, Bofors and Oerlikon, but I ran down the stats anyways.

And found an error in SEALs.

They used the stats for 20x110mm USN for the 20x110mmRB Oerlikon.

Here's what you need to change to make your stats right! 

AP-T is 6dx2(2) pi++, Acc 5, Range 840/4,700, ST 29M, Rcl 3.

HE is 6dx2(0.5) pi++ linked 1d+1[1d+2] cr ex, Acc 5, Range 820/4,600, ST 29M, Rcl 3. 

Ding Dong

Now that I've amended my spreadsheet a bit...

These numbers are no longer valid. 

The 16" High Capacity Mk.13 does:

6dx73(0.5) pi++ linked 6dx24[6dx3] cr ex.

Range is 17,000/39,000 (9.7/22.2 miles) 

ST is 210M.

Rcl is 6.

The 16" Armor-Piercing Mk.8 does:

6dx57(2) pi++ follow-up 6dx12[6dx3] cr ex.

Range is 25,000/57,000 (14.2/32.4 miles).

ST is 218M

Rcl is 7. 

USS Alabama with her shorter L45 guns firing the same rounds "only" gets:

16" High Capacity Mk.13 does:

6dx71(0.5) pi++ linked 6dx24[6dx3] cr ex.

Range is 17,000/38,000 (9.7/21.6 miles) 

ST is 208M.

Rcl is 8.

16" Armor-Piercing Mk.8 does:

6dx52(2) pi++ follow-up 6dx12[6dx3] cr ex.

Range is 23,000/52,000 (13.1/29.5 miles).

ST is 214M

Rcl is 9.

USS Texas with her 14"/45 guns:

14" High Capacity Mk.19 does:

6dx72(0.5) pi++ linked 6dx20[6dx3] cr ex.

Range is 23,000/52,000 (13.1/21.6 miles) 

ST is 202M.

Rcl is 11.

16" Armor-Piercing Mk.20 does:

6dx44(2) pi++ follow-up 6dx11[6dx3] cr ex.

Range is 17,000/40,000 (9.7/22.7 miles).

ST is 192M

Rcl is 9.

FFS Ordnance Bureau!

When the Army realized that the M2 and M3 guns in the M3 and M4 tanks weren't going to cut it for most anti-tank purposes...

OK, they didn't.  The M2 and M3 guns do exactly what they were supposed to do, and the Gun Motor Carriages were supposed to handle the stuff that was too heavy for the tanks.

So they made what we call "tank destroyers," or gun motor carriages.

The TD counterpart to the Sherman is the Gun Motor Carriage M10.

It's got a long 3" gun that's tailored to kill tanks.  This is the M7 gun on an M5 mount.

Towards the end of WW2, they started to replace the M10 with the Gun Motor Carriage M18 "Hellcat".  It too has a long 3" gun that's tailored to kill tanks.  This is the M1 series of guns.

The tank destroyer concept started to wane after the war and we developed a light tank with a long, 3" gun that had a decent chance against a tank.  This is the M32.

They all use the same round, right?

No.

No, they do not.

Despite all sharing the same caliber, they don't share the same case.

Frustratingly, The M7 and M1 guns share projectiles.  The cartridges are named after the projectile so they share designations.  76mm HE M42 for the M7 is a different round from the 76mm HE M42 for the M1.

The M7 gun fires 76.2x585mmR.

The M1 series fires 76.2x539mmR.

The M32 fires 76,2x580mmR.

The manuals that ordnance issues doesn't really distinguish between the 76mm rounds and even forgets there's more than one cartridge length.

What caused me to notice was going through the rounds for the Lee/Grant and Sherman's 75mm M2 and M3 guns.  Those guns both fire 75x350mmR.

But Ordnance doesn't specify that the 75mm Pack-Howitzer rounds are not the same.

The round that started my noticing was the 75mm M66 HEAT-T round and seeing how low the muzzle velocity was compared to other rounds fired by the Sherman.  Even lower than the shorter barreled gun in the Lee/Grant.

This is because the pack-hog fires 75x272mmR!  It gets a couple of rounds that the Sherman never got because it stayed in service a lot longer. 

It's getting sorted.

I have also made my first set of stats for a NBC round.  The M64 Chem round.  Mustard gas!  Not to be confused with the M64 Smoke and M64 HC Smoke rounds.

The Wehraboos Have Failed Me

There are no consistent sources for the weight of complete tank rounds for Nazi Germany.

Worthless AI guesses are the projectile weights. 

Bet They Were Feeling A Little Inadequate

The 8.8cm KwK.43's Pz.Gr.40/43 will do 6dx16(2) pi++ out to 5,950/17,500.

That's got more reach than the same projectile from a Tiger E.

The 8.8cm KwK.36's Pz.Gr.40 will do 6dx13(2) pi++ out to 4,980/14.600.

Those punch 9.6" and 7.8" of RHAE respectively.

The 90mm gun on the T-26 firing a M82 APC-T round does 6dx10(2) pi++ follow-up 6d+2[4d-1] cr ex.

That punches 6" of RHAE.

That's our best armor piercing round.

On the plus side, the Tiger II only has 5.9" of armor on the front of the hull.  That should only be DR 400, but it's sloped for DR 850 and the M82 round will ping...  You need 6dx21(2) to get a Tiger from the front.  We didn't develop a round that could do that until we filed the serial numbers off the Brit L7A1 105mm gun and called it M68.

On the down side, the T-26 firing that 90mm round almost has 4" of armor...  It too is well sloped and gets DR 420.  6dx10(2) penetrates that.

On the gripping side, there were damned few cats of any flavor running about when the T-26 arrived to test out the idea of what would become an MBT.

Wading Through It

Did the 76.2mm rounds today.

Did you know that East China had a long-rod APFSDS round for their modernized Walker Bulldogs?

I didn't.

I also discovered that tungsten is almost the same density as depleted uranium, a little heavier in fact.

I knocked out the 75mm German WW2 tank guns too.  They were very considerate using the same projectile in three different length cases.  Just had to change the velocity to get the stats.

The 75mm HEAT round they came up with in '38 is truly pathetic.  At least by modern standards.

The Hl.Gr.38B only does 6d+1(10) cr ex with a linked 6dx3 cr ex.

The improved Hl.Gr.38C does 9d(10) cr ex with a linked 6dx3 cr ex.

6d+1(10) penetrates a mere 220 DR, just a tad over 3" RHAE.

9d(10) will get past 315 DR, or 4.5" RHAE.

While that's adequate for early WW2, I'd gotten used to Twilight and the M456's 6dx5(10) cr ex linked 6dx3 cr ex.  That punches 1,050 DR or 15" of RHAE.

M494 Update

Back here I had the damage for the 105mm M494 APERS round at 3d cut.

Gun Stats changes that to 1d-2 cut.

The 14 hits at 50 yards only does 2 per hit now and that's 42 damage.

Not a red-mist, but very unhappy with life.

10 consciousness rolls and 3 death rolls tends to make people grumpy. 

Knock Knock

A 16"/50 Rifle Mk.7 firing a 16" HC Mk.13 round does:

6dx80(0.5) pi++ linked 6dx24[20d] cr ex out to 16,160/37,300

16" AP Mk.8 does:

6dx51(2) pi++ linked 6dx12[20d] cr ex.

Updated from here. 

It's hilarious calculating these things in grains!  133,300,000 grains for the exemplar Mk.13 round.

Explosive D has an REF of 0.95 not 1.13, so that changed things a mite. 

US Cartridge 105mm APFSDS-T M900

My old stats for the M900 were:

6dx34(2) pi++ inc; 6,000/18,000 - That's good for punching 518mm of RHA at 0°.

Gun Stats gives:

6dx33(2) pi+ inc; 8,140/26,700 for APFSDSDU.  503mm penetration.

6dx39(2) pi+ inc for long-rod APFSDSDU.  594mm penetration.  "Long-Rod" is defined as a penetrator being 15 times longer than its diameter.  The M900 penetrator is 25x603, 23 and change to 1.  It's a long-rod.

A bit short of both benchmarks I found back in Feb '25.  The round's performance is still classified (sorta) so there's not a lot of official information, but a great deal of "already leaked" information.  War Thunder thinks 522mm.

But 6dx39 is in the ballpark of what I think it should do. 

It's a game, so the important thing is the relative values come out about right even if the precise numbers don't quite.  Gun Stats even has a section about how to use stated penetration values to determine damage.

Take the RHA penetration in mm * 0.787 / armor divisor and that gives dice.  6dx34 in the case of 522mm!  But, like I said in Feb '25, I think it punches more, so I'm going with the long-rod numbers!

Moar Gun Stats Shenanigans

In the world according to High Tech, an M1 Carbine does 4d+1 pi damage.

An M4 Carbine does 4d+2 pi damage.

I don't think that .30 Carbine really does almost the same amount of damage as 5.56.

Gun Stats thinks it should be 4d pi-.

That better suits its reputation, I think; and it fixes a long running problem with where the line between high and low velocity is with small caliber rounds.

Gun Stats has a little table for the length/diameter ratio by caliber and if a .30 round is LDR of less than 3, then it's pi-.  The 110 grain bullet of M1 carbine is definitely under 3.  2.24, to be exact.

I've long suspected that an errata should have been made for it, but Hans-Christina Vorsitch long maintained that 4d+1 pi was correct. 

It's Not Just The Kick

Playing with GURPS: Gun Stats has brought one stat to the forefront.

Rcl, or recoil.

At first glance, this is how hard a gun kicks and you'd think that the more it hurts your shoulder, the higher the Rcl should be.

But...

The game effect of the Rcl number is how hard is it to get a second shot on target.

A bolt gun is going to be harder than a double rifle because you have to work the action.

A semi-auto gun has moving parts that might make the gun move more and make it harder to get a second shot on target, even if the action absorbs some of the pain transferred to your shoulder.

I was calculating some of the big game rounds and noticed that a break open action had significantly lower ST and Rcl than a bolt gun.

Case in point: .375 H&H.

It's a good example because we can still get double rifles in it, as well as bolt guns.

A Winchester Model 70 Safari is 8.5 lb. loaded and has ST 11, Rcl 5.

A Chapulis Iphisi is 9.3 lb. loaded and has ST 10, Rcl 3.

The difference in mass is not the deciding factor, but the change in constant from 0.5 for bolt guns and 0.25 for break-opens.

Despite the RoF 1 for the bolt gun making it seem like there's no reason for the Rcl value, there are rules for firing faster than the Rcl number suggests.  All that manipulation of the bolt comes to the foreground there.

A double gun, however, just needs you to pull the other trigger.

Gun Stats significantly alters the ST and Rcl requirements of some guns down to the point where it's conceivable that an averagely stat'd big-game hunter could fire two rounds with good effect.

Gun Stats is generating ranges that are more in line with what I've read about African hunting than what High Tech said they should be too.

Bigger Bar

I found new information about the bear referenced by Ron White.

The 7mm part of the routine bugged me.

Turns out it was 7mm Remington Magnum, and a semi-auto rifle not a revolver.

The bear tared out at 1,600 lb., so it's ST 23 not 21.

It absorbed 12 rounds, total of 7mm Rem Mag. 

7mm Rem Mag does 7d+2 pi.  Average roll is  26.  24 penetrates for 24 points of damage per shot on average with FMJ.  A soft-point would do 7d+2(0.5) pi+.  The average roll would get 20 to penetrate for 30 damage.

The only semi-auto I can find that has more than 5 shots that's chambered in 7mm Rem Mag is an AR10 derivative from Great Lakes Firearms & Ammunition, the GL10.  There's a lot of red flags with the story, see below...

Because of the recoil (Rcl 4), prolly gonna take one shot per round and not the full 3.

BALL
First shot drops the bear to -1 with a consciousness roll and half move and dodge.
Second shot drops it to -25, consciousness roll and death roll.
Third shot drops it to -49, consciousness roll and death roll.
Fourth shot drops it to -73, consciousness roll and death roll.
Fifth shot drops it to -97, consciousness roll and death roll.
Sixth shot drops it to -121, auto-death.

HOLLOW POINT
First shot drops the bear to -7 with a consciousness roll and half move and dodge.
Second shot drops it to -37, consciousness roll and death roll.
Third shot drops it to -67, consciousness roll and death roll.
Fourth shot drops it to -97, consciousness roll and death roll.
Fifth shot drops it to -127, auto-death.

Clearly our ranger rolled below average on his damage dice, and appears to have missed a few times with the first magazine.

Oh, and it's appropriate that I GURPS'd this all up because it appears to be an internet hoax! 

According to Gaber and department records, the bear was shot Oct. 15, 2001, on Hinchenbrook Island at the mouth of Prince William Sound, by 22-year-old airman Ted Winnen from Eilson Air Force Base.

Winnen was deer hunting, but bear season was also open. He and a friend spotted the bear fishing along a river about 40 yards away. They decided it was a shooter, but the bear disappeared in the underbrush. It had not seen or smelled the hunters. It reappeared about 10 yards away. Winnen shot it through the head with a .338 Winchester Magnum (not a 7 mm mag.) and bowled it over. He then emptied the rifle into its vital area to make sure it was dead. It did not charge the hunter(s) as was claimed.

Official records showed that the bear was an Alaskan brown bear and measured 10 feet, 6 inches from head to toe and weighed an estimated 1,000-1,200 pounds. It was a nice, trophy brown bear, but it wasn’t 12½ feet at the shoulder and didn’t weigh 1,600 pounds. Nor was it even close to breaking the world record.

 1,200 lb is back to 21 hit points.  .338 Win Mag does 8d pi.  That's an average roll of 28.

I'm going to assume that "through the head" means a skull shot, so 24 penetrates for 96 points of damage, dropping the bear to -75 in one shot.  That's one consciousness roll and three death rolls, and clearly the bear did not make one of them (a total of 59% to make all three death rolls is, of course, not a sure thing).

The real account still GURPS!