SQUEEZE BORE | High PEN High VELOCITY (War Thunder Sd.kfz.221 (s.Pz.B.41)

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SQUEEZE BORE | High PEN High VELOCITY (War Thunder Sd.kfz.221 (s.Pz.B.41)
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Intro Music - • K-391 - Everybody | Ho...

[@badbutton5869]

Fun Facts Phly, i used to be a Machinist before enlisting in the Army, and made Barrels for everyone from Remington, to Colts, and this is found in almost every rifled, (Land and grooved applys to larger calibers) barrel in modern firearms and tanks. Though not to the extent of the B.41. Mostly down to sub millimeters of a difference. Every modern day rifle, and hand gun barrels are designed this way. While the whole barrel is typically rifled there is a certain point where the bullet meets the rifling. This is called the "Bite". The “bite” of the moving bullet during shooting, is subjected to the greatest stress to barrels overall. As you said these barrels didn't last long as they squeezed a 28mm out of a 20mm. Let's take a 7mm mag rifle for an example, most 7mm mag barrels at the end of the bore is more of a 6.95mm. To get the same effect, just not as drastic. The more you know.

[@riheg]

Bad Button fascinating stuff

[@johnbeauvais3159]

That's why you can check the condition of the barrel erosion by sticking a cartridge down the muzzle. The casing should not touch the muzzle

[@badbutton5869]

This is correct. If you take say any, but for an example a 308, and try to put fit on the exit end of the barrel or muzzle as you were, if not worn out, should not be able to fully fit. That is why for squib loads, you should always try to push the round back out of the receiving end, or chamber.

[@johnbeauvais3159]

Bad Button interesting you mention .308 because that was where I learned this trick, I was buying a navy converted Garand and wanted to see if there was any life left in the barrel. Also interesting not the S&W Model 1905 revolver chambered in .38 S&W was such a weak round that it couldn't be shot out of a 6" barrel because it lacked the pressure to exit the barrel

[@hazed1009]

Bad Button thanx for info

[@kibblez9241]

Phly, I think you are misunderstanding how the squeeze bore works. The round is a 20mm penetrator with metal skirts or flanges on the shell. These skirts give it an increased diameter to 28mm and are designed to be crushed inwards as the round progresses down the barrel. This enables a 20mm round the have the same amount of charge behind it as a 28mm and results in a projectile with vastly higher velocity.

[@rastas3742]

This

[@sauronthedarklordofmordor2990]

I believe that this greatly reduces the life of the cannon

[@kibblez9241]

LOTRSAURON you are correct. The barrel could only handle about 500 rounds before needing to be replaced. But in general early high velocity guns had relatively short service lives even with normal barrel construction. For example the Russian ZiS-2 57mm had a service life of about 1000 rounds. And funnily enough, the North Koreans still use the ZiS-2. A NK ship was intercepted smuggling weapons from Cuba back in 2013 and they found ZiS-2 ammo on-board.

[@Baked_Ziti]

@@kibblez9241 +1 for education

[@FrohSim]

Also of note, this is all pretty much the same principle (and I'd imagine mostly replaced now by) for velocity increase as discarding sabot. Smaller projectile, larger relative charge.

[@PhlyDaily]

old music i cri

[@hydrixs6996]

PhlyDaily Hi! I did ur first comment, please teach me your ways please.

[@davidshuvalov6311]

Nice profile pic

[@ten10old80]

PhlyDaily fly a me 163 B with the minimum fuel load

[@GRIM56]

I love that music

[@Hunter-rr5ue]

The only thing you should see is Hans death stare

[@pupinator98]

love the shock from about 3:45 to 4:00 or so as he casually pens a T34's side at 400m or so

[@viktorvincze909]

Why does this thing even have crew replenishment?

[@bojanradic6440]

Eric Sales not eny more

[@riheg]

Viktor Vincze Donaugh Trump

[@maximecarpentier9597]

Viktor Vincze i think in arcade there is still the last man standing mechanic

[@jmac2o229]

cocaine

[@yungdomino4718]

Because fuck you thats why

[@Arthurzeiro]

The zis-30 has some memable competition.

[@riheg]

ArthurAlcantara Donaugh Trump

[@amacare123]

Marcel Huchwajda wut.

[@ChaosphereIX]

Now where is my Little John adapter for the Matilda and other 2pdr guns!? Could be a module like added armour.

[@flippedstug9517]

That would be such a major upgrade it would warrant a new BR, so it would have to just be a separate vehicle.

[@ChaosphereIX]

The Matilda is an exception to that, at 3.0 it is overtiered anyways. So with the adapter, it might even be competitive.

[@qwerty123il]

It will increase penetration but reduce damage with the smaller round... would it really need a huge BR increase? Let’s be honest the 2pdr sucks so badly

[@Rev-Counter]

I heard that the ammo used for the adaptor was more effective than the standard 2pdr anti-tank ammo, so many crews used the new ammo without the adaptor.

[@masonlariscy530]

ChaosphereIX It would be something that would actually make the Matilda useful

[@Ashfielder]

Hey, uh hey play the squeezebore top tier!

[@riheg]

Toby Wood Donaugh Trump

[@PersimmonHurmo]

11:57

[@jwellipweid2076]

@@PersimmonHurmo you dont get the joke, do ya?

[@PersimmonHurmo]

@@jwellipweid2076 no u

[@jwellipweid2076]

@@PersimmonHurmo not a great comeback

[@saltykrug]

Oh man another armored car!!!! I friggin love them! The Germans and Brits had so many, I wish they'd add more armored cars into the game, there are plenty of moderns ones too!

[@spc1481]

Yeah, I totally agree with you. :)

[@Insomniac3d]

@kirk shipp well this aged like a fine milk

[@sebastianprimus3804]

Im glad gaijin doesn't forget low tier tank

[@pikkuvarpunen-2.7182]

Unlike some of its' competition. *cough* WG *cough*

[@pikkuvarpunen-2.7182]

Correction, they give out a free garage slot because you end up selling the crap tank. :P (Gregg rules, ok?)

[@Demospammer9987]

>Requires Rank III to get a Rank I event vehicle

[@NathanOkun]

The Squeeze bore was essentially an APCR/HVAP with the outer casing being designed to be crushed inward so it acts much like an APDS with the outer casing still attached, but trailing the tungsten-carbide bullet core like a short arrow shaft instead of flying off completely. The British had one called the "Littlejohn" attachment that added a screwed-on long squeeze-bore barrel add-on to their old 2-pdr tank/anti-tank gun to make it able to penetrate the smaller German tanks (maybe a Panther at point-blank range in the rear, like the old 75mm Sherman against a Tiger I from the rear). The special APCR-like ammo only was squeezed in that extension, so only it, not the whole gun, wore out fast and could be replaced by merely screwing on a new one. When APCR and APDS came out more frequently for regular guns, this jury rig for older guns went away as too expensive.

[@spork9255]

I read up on it on wikipedia, the round itself is the same as a 20mm round but has these ridges on the side that make the round 28mm in diameter on the ridged part; the ridges get squeezed down with the barrel until they are bent back to make the whole round 20mm and able to exit the barrel. These ridges don't allow any gasses to escape past the round until it exits, resulting in a very high muzzle velocity.

[@elijay8373]

"I'm so good at this game" *Kills 40th AI in a row*

[@monolitwoods]

HANS GET ZE ENGINEERING MANUAL

[@yayeet7274]

Did you actually know that during the early Blitzkrieg years this was used as a mobile air support caller?

[@arrantownsend9774]

Who would win? Every tank ever\one sqeezy boi

[@ironduke5058]

Nothin Poppin lol you watch comment awards ey

[@ironduke5058]

Who would win Advanced,one of the most modern tanks In the world the M1Abrams Or *One squeezy WW2 German boi*

[@ironduke5058]

The Gaming Fascist Yeah I know no shit they're outdates you can't expect the WT models to be the most modern and actual models,the army wouldn't allow it.

[@atomsmasher9279]

Nothin Poppin who would win the American T34/ one squeezy boi

[@Dushess]

@@atomsmasher9279 a 2.8 cm in a right spot, of course.

[@fireraid2336]

Lol that was me in the Type90 towards the end.

[@hitoshisawa8479]

Fireraid233 😂😂

[@randomt-9034]

"If you feel useless, remember that French low tiers and this vehicle has crew replenishment."

[@blastdude89]

The projectile carried two external flanges; as it proceeded toward the muzzle, the flanges were squeezed down, decreasing the diameter with the result that pressure did not drop off as quickly and the projectile was propelled to a higher velocity. The barrel construction resulted in a very high muzzle velocity - up to 1,400 m/s. The bore was fitted with a muzzle brake. The horizontal sliding breech block was "quarter-automatic": it closed automatically once a shell was loaded.

[@frizzoraffo]

Can call it a sort of APFSDS, the round had a 20mm diameter with squeezable fins. It travels so fast because the pressure is used more efficently along the whole lenght of the cone-shaped barrel.

[@stalinium4769]

I love the old I intro song pls use it more often it makes me nostalgic...

[@9999AWC]

Got a challenge for you Phly: To have fun while playing the He-162 Salamander in RB. That's it! No need for kills or being 1st or any of that. You just need to have a good time phlying the Salamander.

[@totenkohpf4976]

The way this works is they are taking your standard 20mm bullet and putting into a 28mm shell casing. The chamber designed to hold it snuggly. The barrel setting depends on the maker but it is lined up with the barrel tip. The round is squeezed as it travels down the barrel starting from the initial starting diameter from the shell back down to 20mm allowing all the force of the larger powder charger to push the slug at a greater velocity than is reachable with standard munition shell types. Which in this case taking a 20mm bullet and instead of necking it for that diameter like normal the neck is increased to 28mm with just a small amount of squeeze room in the shell. The germans also made a 75/55mm cannon with squeeze bore for another scout design

[@j.muckafignotti4226]

The Krafty Krauts experimented with several squeeze bore guns during WWII, culminating in the Pak 41. It used a crushable tungsten collar as an obturator for the squeeze process during firing. The reason this barrel/round was abandoned was the cost and difficulty in manufacture. It did exceed 1200 m/s though.

[@AnikaJarlsdottr]

awwww, it was so sweet that the xm1 towed you away from the bombs, that was some cute af older brother vibes. I love it ^w^

[@spakes6561]

Everyone including Phly, it’s called a Taper Bore. It uses Tungsten shells as it was the most dense and durable metal known to man, and as it traveled down the barrel and was squeezed the pressure in the barrel would increase which in turn increased velocity

[@circleofsorrow4583]

Haha...no.

[@AKGuru4774]

PhlyDaily: As a machinist and custom gun shop owner, The B.41 had a slight change in MM every 8.5 inches, it would be 1mm smaller. That means it is squeezing that 28mm steel core down less than 1/8th of a MM per 8.5 inches, which is pretty drastic to say the least. But it is also very unlikey to explode inside the barrel. I have made certain competition shooters rifles into squeeze bore rifles. As in the rifle is .308", I make the rifles first 12 inches .308", next 8 will be .3065, the last 6 will be .30575" using solid copper bullets only. Results were rather, surprising. Increased pressures drastically after the first 16 inches, but seemed to produce and maintain velocity and accuracy.

[@Colonel_Overkill]

The way a squeeze bore works is actually the shell fired has a ring around it like a mushroom head and as it goes down the bore it is compressed until it ends up being the final size as it exits the barrel. These were developed first and while there were many problems with them, the general concept was developed further into the APCR and APDS concepts that came out later. This is a gross over simplification of the technology but gives a basic understanding of the principles involved.

[@xXxTripleHxXx]

The projectile had an out layer of ectra soft tungsten to allow sqeezing it to a smaller diameter. This means the pressure inside the barrel is alot higher because the round has much more resistance to being eccellerated. The requirement of tungsten was one of the main reasons Germany did not continue to use those guns. Its appeal was to get more penetration compared to regular setups. Another use was the littlejon adaptor that was used to extend the servicelife of the aging 2pounder gun found on for example Matilda or Valentine tanks. Im curious why Gaijing does not add a Matilda with this configuration as it would cure its "bad gun" syndrome pretty darn effectively

[@HMSHOOD1920]

No, the outer was of an aluminium alloy, the inner core was made of tungsten.

[@rodneypayne4827]

Bring on the Sd.kfz 222 Go cart with bit more armor!

[@Rev-Counter]

Yess!! It should be easy to do as well, just the turret of the 140/1 and a few minor changes :)

[@cpt.mirones5109]

same on the puma its a bit of a shame they leave these easy work out

[@endlesnights3817]

It's a different turret from the 140/1 That's the turret from the Sd Kfz 234. The only bit that's the same is the front plate. Though they do appear similar.

[@Tadeas_Plachy]

This principle was invented and patented by Czechoslovak small arms designer by name of Janeček. He made few anti-tank rifles based on that principle which were used by Germans in WW2 and they became the base for some anti tank guns (also used on British WW2 tanks). The projectile had hardened core surounded by sort of hollow jacket which was easily squezzed to smaller diameter. It allowed for use of bigger shell casing with greater powder filler for higher velocity. But smaller diameter projectile had superior balistics and drag characteristics to larger calibre.

[@jonathanzobel1662]

the Brits also used the squeeze bore principle on their 2-pdr with the littlejohn adapter. Wot already has the gun on their Matilda tank. Historically the adapter doubled the velocity and penetration to nearly 120mm of pen. So basically it could knock out a tiger 1 frontally if it was close enough. But the 40mm 2-pdr round was squeezed into a 30mm round so it may not have nearly the same shrapnel effect.

[@alanwatts8239]

13:24 that was so funny holy shit XD

[@jheybrent]

I hope the British gets their Little John Adapter as well

[@FirstLast-cg9ic]

Jhey Brent Bondoc why u got upsidedown flag of Philippines, we’re not in war

[@laundreu]

The way squeeze-bore and taper-bore guns like the sPzB41 and company work is pretty simple. There's a high-density core, usually tungsten but sometimes hardened steel, surrounded by a soft metal casing. When it's fired, it travels through the tapering barrel and the soft metal is swaged down, so the high-density core doesn't have the lightweight casing slowing it down through air resistance. (This also increases the pressure in the barrel, giving an extra bit of oomph.) APDS does the same thing, by discarding the casing once the round leaves the barrel and leaving the penetrator flying free, but unlike squeeze-bore guns, you can fire bigger HE warheads out of non-tapered barrels.

[@Supernionra]

The squeezebore principle used by German guns, such as this one and the Waffe 0725, is fairly simple to understand. Notice how it's an APCR round in-game. The round (similar to APCR), before it's fired, has "fins" that give the shell a diameter of 28mm. As the shell travels down the barrel, the barrel diameter gets smaller, which compresses the "fins" on the round, which gives it a new diameter of 20mm. This gives the shell a makeshift pressure seal that increases the pressure in the barrel so it leaves at a higher velocity. There are some good images and photos of these shells online.

[@WorldatWar21]

KV-2 watches video. KV-2 laughs .

[@edwardarruda7215]

KV2 round dosent even need to be direct hit.

[@Feffdc]

We need Kv-2 squeese bore

[@riheg]

T M Donaugh Trump

[@Progamer-ih8sb]

Tiger 2 see ur message Tiger2 laughs...

[@DroopyPenguin95]

Pro gamer I-Go Ko sees your message. I-Go Ko go cry in a corner

[@FoxRacingGaming]

"" HANZ IZ THAT YOU?! "" .... "" NEIN! "" "" GO , AVAY "" XD -PHLYDAILY 2018

[@beardo52]

The Germans used several different guns of the squeeze bore type. The actual projectile remains the same size, (20 mm)it is the Flanges attached to the projectiles that deform. Further, only Tungsten carbide projectiles were useful in this type of weapon, as just making Steel shot go faster results in the shot disintegrating on impact with Armor. They were used for only a short time by Germany as they had very little Carbide available to them, and Hitler order remaining supplies for the making of Machine tool cutters. Also, it's Wall-O-nia, the non french part of Belgium.

[@BlitzFromBehind]

The word ya'll looking for is tapered bore, not squeeze bore just FYI. (squeeze bore is the principle, tapered bore is the actual physical part) And it's not an APCR projectile. It was 2 sets of "rings" that fold down as it travels down the barrel. This allows the pressure to build up thus the muzzle velocity increases. And as a tidbit the barrel life on those things was like a 1000 rounds.

[@krippster1798]

Kv 2 squeeze barrel

[@otaviocamanho1135]

Phly, i have a good challenge for you!! Play the M48 in stock configuration (you can uncheck the modifications making it stock) Or...play the M48 using only the APCR shell. Good luck, you will need it Attempt #60

[@riheg]

Otávio Camanho Donaugh Trump

[@Fast85FoxGT]

By FAR the worst stock ammo grind in the game is the m48, but as soon as you get m82 and HEATFS it changes the whole tank up

[@otaviocamanho1135]

Bad enought to pen a Ru251 at point blank and not angled , hit the main ammo rack, and the ammo absorb all the damage and gets "orange"...true story

[@ODST6262]

28/20MM was developed as an airborne AT gun for the Fallshirmjager. It is a 20mm HVAP round with a tungsten core and metal skirt that makes the round 28mm in caliber. Squeezing the skirt down increases the time in the barrel allowing the gas pressure to both build and push the round for a longer period of time. Barrel wear was worse than a conventional 20mm but it is hand loaded, not loaded from a magazine so the rate of fire is slower. This gun was also made in 47/45mm, and 77/75mm. The problem that stopped production of the gun was ammunition production was halted on these guns as well as on the HVAP (PzGr 40) ammunition in 1942, except for the 50mm PzGr 40 as it was the only German anti-tank gun that was effective against a T34. All of the guns continued in use until the ammunition was used up. Ammunition manufacture was stopped because the tungsten was needed for tooling for production, and Germany had a limited supply of tungsten.

[@ShortThrowShifting]

The Gerlich principle is what this gun employs. The shell itself is a fixed 20mm diameter, however, the shell has 28mm driving bands made out of a synthetic material, often hardened rubber, which wear down as the shell travels down the barrel. These driving bands make a complete seal with the barrel, and, through this, you can utilize a much larger powder charge/casing, and the further down the barrel the projectile travels, the smaller the surface area the gasses have to act upon, increasing the velocity exponentially. Very little (if any) gas escapes around the shell, making it very efficient. That being said, the Gerlich weapons required frequent cleaning of the rifling grooves, the shells were costly to produce, and rapid fire for prolonged periods could easily overheat the barrel. There's also a 75mm Gerlich gun that was produced in limited numbers.

[@aguirregaston13]

thanks phly for putting that intro music again in all your videos

[@alexandru.g8746]

*muffled eurobeat intensifies*

[@BDNeon]

They did this concept with larger guns too. There was a larger 42/28mm which was analagous to the 37mm pak 36 but had double the penetration, and a 75/55mm which could penetrate over 200mm of armor at close range. The reason the idea didn't persist and these weapons didn't become standard issue with the exception of the 28/20mm is because the rounds were traveling so ludicrously fast that they required tungsten cores, solid steel rounds would have just shattered when hitting tank armor at that velocity. And tungsten was hard to come by in wartime blockaded Germany, so when stocks ran low they ditched the larger calibre guns but kept the 28/20mm in service because it didn't require much tungsten for its proportionately much smaller rounds, and was light and handy and high performing enough to be a useful gun.

[@ordikaskirita5234]

PhlyDaily, what you are actually playing is called a Gerlich Gun or Gerlich Rifle, so named after its inventor. They were first used with frightening effect in North Africa versus the Allies, surviving pieces were used up until there was no more tungsten penetrators available or the barrels gave out. The concept was valid. Because Post War in co-operation with Israel a 60mm version was developed and installed on Israeli Shermans, lets say T-62 tanks had a very hot reception.

[@MeronBridgeMR]

*DRIFTOOO???*

[@maruftim]

ye German engineering.

[@jiroproduction8831]

0:01 when i drive this ducky. It’s annoyed me

[@metzgerdan]

Most tapered bore guns fired tungsten ammo those had a core (tungsten) and something like a sleeve made of some other malleable material (aluminium or lead) that would provide gas seal and rifle profile the tungsten core would not get in contact with the barrel as would damage the barrel. Most of these guns were made for paratroopers (Fallschirmjäger) and mountain division (Gebirgsjäger, Vinatori de munte) guns that were carried by people or animals not mounted on cars or rarely mounted on cars

[@drewisaac9884]

it's called apcnr or armorpiercing composite non ridged. The Shell has a 20mm core and side skirts made out o a softer lighter metal like aluminum. When the shell gets propelled out the bore those skirts are pushed flushed against the side of the shell making it more aerodynamic. the high pressure isn't the only reason the muzzle velocity is so high. it has a lighter shell. Armor piercing Composite non rigid has the advantage over APCR because it is more aerodynamic than APCR. APCR has a lower crosssectional density meaning it is more effected by drag.

[@joshgarner8317]

Hey phly a big Birdy (themightyjingles) said that you are going to be at tank fest this year

[@maruftim]

Ye, he said it on stream.

[@joshgarner8317]

Don't watch the streams to often

[@mr.narwhal9034]

“[insert WoT/WoW player here] gets a dose of surprise butt sex” -Jingles, probably since he learned to talk

[@samozelonka5756]

10/10 would squeeze again

[@adamblakeslee5301]

Squeeze bore compression would not only concentrate the kinetic energy of the round but cause the shell to become hard and brittle. Of course, the additional resistance would put more stress on not only the barrel but the breach. Basically, the whole thing was asking to blow up in your face.

[@GrasshopperKelly]

You can call it a "28mm squeeze bore," or a "28 to 20" if you want something short. It's primarily a 28mm. The shells are all 28mm. The same as the Matilda 3lbr with the little John adapter. The shell diameter shoved in the breach was the same.

[@mr.bruhexplains1538]

then I wanna see u play the il 28

[@mr.bruhexplains1538]

phly play the bf 110 with rockets on dev server

[@seriousgoat76]

They are air to air rockets.

[@kevinwynott7755]

The squeeze bore got its damage from having a tungsten carbide core to its round. The outer layers were soft metal. The 2.8 CM PzB fell out of favor for two reasons: The barrel wear, which you noted, and the fact that tungsten carbide was a strategic material, necessary for industrial tools,and in fairly short supply.....that LAST thing they wanted to do was go around launching The limited supply of it they had across the Russian steppes!!! There were larger versions,but never went much further than prototypes.....

[@challenger2205]

The early squeeze-bore cannon used a shell slightly larger than the output caliber, with external thin soft metal sabot outside the shell, therefore provides a large amount of energy on to a small projectile-- yeah, just like discarding sabot, but in an inefficient way...... It worked in the early days pretty well though.

[@charlieweir4060]

Best combo, R2Y2 keiun-KAI v3 and the best best landship, the Type 2 Ka-Mi. Attempt 40

[@riheg]

Charlie Weir Donaugh Trump

[@Jonashall1]

I have girls squeeze my barrel all the time. I usually don´t last long either.

[@JK-ei7wr]

Jonas Hall …clearly you're a 30yo virgin

[@hazed1009]

Jonas Hall lol

[@whatarenames1395]

Your Typical Boss you clearly don’t understand a little “innocent” humor.

[@jonahsmith2708]

@@JK-ei7wr the joke went straight over your head

[@JK-ei7wr]

It says I wrote this comment a year ago yet I feel like I wrote it a few days ago…😬

[@boitle]

The rounds were made specifically for the gun. They had an outer shell of soft malleable metal around a solid core. This is why it doesn't blow the gun up.

[@old_guard2431]

I would say it is primarily velocity and the tungsten core. Round is not much heavier than the MG 151/20 (OK, an airplane gun) but velocity - 1400 or so m/sec versus 800 or so m/sec. In a way you could see it as a precursor to the sabot round - get a thin very hard projectile moving at an insane speed and it is not going to be inclined to stop.

[@darvinblack7599]

The round is 20 mm all the time. It just flies through 28 mm space. The conical shape keeps same pressure through all the barrel, which gives bigger speed to the bullet.

[@ronaldthompson4989]

The sPzB 41 is a purpose built antitank rifle (infantry weapon replaced by panzerschreck) that was fed 20mm tungsten slugs with 4mm long aluminum flanges.the LittleJohn adaptor for the British 2 pounder was the only conversions of old guns worth noting

[@Vexman2200]

The sPzB 41 28mm gun is a crazy cool concept, they had squeeze bore cannon of 42mm and 75mm too. It squeezes a 28mm to 20mm round. the only issue is the velocity of those guns slows down fast and generally were known to have only close range penetration that drops off relatively fast. really great concept. I could only imagine what it would be like if they had a VK903 which had standardized version setup for a tank called the 28mm KwK 42 and could have implimented a clip of sorts like the Pz.Kpfw II

[@ecash00]

This is before they used Sabots.. its a neat trick to use a 120mm cannon for a 90-100mm shell Wrapped in a sabot... It was a way to use MORE powder to fire a lower size..

[@tatejordan385]

It's not as amazing as it first sounds, these squeeze bore projectiles are only about 20mm to begin with but the they have metal skirts on the side that food into relief cuts in the sides on the projectile. The whole concept is to create a very good gas seal like the old minné balls of the civil war, but with different execution. As the gas pushes the projectile down the bore it is squeezed by the sides of the barrel until it reaches the target diameter of 20mm where it then has a straight section for the rifling, which because this is a squeeze bore, the projectile has a very good grip on the rifling

[@USSWisconson]

"You would think we'd be able to engage this T-34" ~famous last words.

[@lunarpollen]

someone else has probably already commented, but the round isn't 28 mm compressed to 20, it's a 20 mm round with flanges attached to make it 28 mm. You wouldn't be able to compress a round, but the flanges are "squeezable".

[@NathanOkun]

The narrow APCR and APDS projectile cores, being of a heavy non-steel alloy (TC or DU), and hitting at a very high velocity, shatters the armor and blows it into the tank like extra very fast bullets ricocheting around, doing this a lot more than the slower, larger regular AP rounds, even though the larger rounds make up for this when they penetrate by making a bigger hole with fewer fragments per areas holed but a larger hole to compensate.

[@Shitbird3249]

It it’s the sabot before sabots uses a softer metal like tungsten also expensive at the time for Germany, and it mainly just a band put around the shell to achieve the velocity thus penetration along with proper round material.

[@Para-tc5uv]

28mil squeezed to 20 Enemy: Time to die Phily: I don’t think I will *continues to eliminate 8-10 people*

[@praetor678]

Tungsten core wrapped in light alloy finned out. Fired the light alloy squeezed down, (folded back) and the round exited barrel at 20 mm. Extermely fast but loses speed quickly because it still has the squeezed down alloy wrapped around the tungsten core. Think of it as a sabot that doesn't discard. Tungsten was needed for machine tools more the as ammo. There was a larger gun that they also made 4.2 cm Pak 4. Shell came out as 28 mm. Airborne weapon.

[@praetor678]

Pak 41

[@christopheranderson2520]

It was also called a taper bore gun. They used tungsten carbide rounds but was not used that much because tungsten was important for tool production. But they were very effective.

[@General_Griffin]

The barrel of that gun doesn't explode because the slug of the cartridge it uses isn't solid around the outside, meaning they basically have flanges going lengthwise down the slug that get smashed down, increasing pressure and thus velocity. Very interesting! But what's more, in 1942 the Pak 41 75/55 mm cannon entered service. This thing pushed a 16.5 pound projectile (which is massive for a 55 mm round) at around 3,600 FPS or 1,100 M/S at the muzzle!! With a maximum range of 4,500 meters! That is absolutely fucking insane!

[@speedycake5824]

at a guess the squeezebore basically starts the shell as apcr but by the time it leaves the barrel its basically AP shot because the barrel effectively makes the shell more dense

[@shturm6915]

More than 2 years on, the Sd.Kfz. 221 with 20mm squeezebore is still good. Just find a good camping spot and fire away, if you’ve done everything properly you’ll soon get some easy kills.

[@markprior7971]

This is a taper bore gun not a squeeze bore. It uses APCNR ammo (armour piercing composite non rigid) with a collapsing skirt. Based on Gerlich's patent the bore decreases gradually along it's entire length while a squeeze bore tapers in one short section only. Squeeze bores were usually add on adapters for older guns.

[@collinboyd6337]

The only part that typically squeezes is the skirting (like on an airgun pellet (both 1/4 way from tip and at the end). The center that does not squeeze is solid tungsten. Thats the penetrator. The germans ran out of tungsten and thats why these guns were not common 28/20, 42/37, 75/55 (and one other but I forget the size)

[@snotcycle]

when you consider a squeezebore 28/20mm think about the fact that the material has to go somewhere, this lengthen the projectile as it is squeezed. The ending effect is a very long pointy projectile (very high sectional density) and thus acts similar to an APFSDS round. Especially considering APCR rounds have a tungsten penetrator.

[@Lord.Kiltridge]

It doesn't squeeze the whole bullet. The projectile carried two external flanges; as it proceeded toward the muzzle, the flanges were squeezed down, decreasing the diameter with the result that pressure did not drop off as quickly and the projectile was propelled to a higher velocity.

[@deanmurphy7307]

For WWII the machining on that barrel must have been phenomenal for it to drop in measurement consistently.

[@thatguynameddan2136]

All about that increased cross-sectional density. Soft outside with a tungsten penetrator core. Wonderful deformation of the outer jacketing even if it screws rifling hard as hell. Gave a lot of life to the brit 40mm as well.

[@masonlariscy530]

I'm pretty sure the ammo was a lot like APCR ammo where you had a small diameter penetrator made out of a hard metal (hardened steel or tungsten) and a skirt made out of soft metal and unlike in APCR where you'd fire out a normal barrel and lose a lot of velocity quite quickly due to the skirt increasing surface area and reducing the overall density of the projectile in a gun that changes diameter the barrel gets smaller and hugs the skirt of the round to the penetrator thus allowing for a greater projectile density and less surface area thus improving aerodynamics and long range velocity

[@kevincostello3856]

German Taper- Bore ballistics was incredible for it's time.

[@kanyeeast8450]

The Germans actually made a 50mm squeezebore, which at either 10 or 100 meters, had around *195 mm of pen!* I would love to see it added to the game as say, a gun truck or towed arty from a truck.

[@CaptPatrick01]

If Simulator battles were truly simulator, then every time you fire this gun the barrel will slowly fade to yellow, to orange, to red, then it breaks itself and you have to use the repair function to replace it. Also, best way to use iit in top tier would be to seek out and ambush lighter vehicles, such as dangerous ATGMs and IFVs in densely cluttered areas, using your small size to conceal your movements. You are equipped with what is essentially a glorified Anti-Material Rifle on wheels.

[@viliamskoruba9782]

Those barrels had lifetime around 400-500 shots if i remember right. Sooo.

[@viliamskoruba9782]

Even if it had 100 shots lifetime it would be enough to not break in single battle.

[@Andrew-mv5kt]

11:45 - "she blew off an A-13"

[@johnohlhausen2741]

I think the phrase you're looking for with the swagged 28-20mm squeeze bore round is "heavy for caliber".

[@brennlbern]

It's 28mm cannon in 20mm barrel, the heat(from friction) and pressure can thin it down to 20mm as longer it gets become a form of sabot with more mass.

[@brennlbern]

"Nadelschütze"

[@paul.facciolo6985]

Well it kind of makes sense it shrapnels better than an apfsds 105 because after the sabot is gone most modern apfsds rounds are only ~28-30mm, also the lower velocity results in more shrapnel.

[@spiderjerusalem8284]

I love the SdKFZ models, they look like oversized VWs with guns.

[@heirofaniu]

It isn't the entire round that gets squeezed, the round actually has a "skirt" on it which is what creates a gas seal and is actually the part of the round which gets squeezed against the bore of the rifle.

[@gustavusadolphus425]

Its called a taper bore gun, one of the three calibers of such weapons made. It is also a 28mm, not a 20mm. it exits the barrel as a 20mm round but enters the breach as a 28mm

[@stevendenton8994]

Its also making the projectile denser ....and the squeeze bore would make it behave more as a sabot....wild idea! But unique

[@GirhenZabi]

The Germans measured their squeeze bore ammunition with the before-squeeze diameter, so 2.8cm s.Pz.41. I think this is also a general practice among other users of squeeze bore weapons.

[@modelmagician3743]

Tungsten 20mm slug surrounded by a softer special cocktail mix metal. This is going to be fun to play, I think what would be hilarious if gaijin added the Kubelwagon with it back seats removed and a 20mm Flak38 fitted in its place. The Germans actually produced these.

[@arnoldkearimal]

2.8 cm sPzB 41 was the official designation from what I can tell....it was classified as a 28mm, even though the tungsten round squeezed down to 20mm. Also, it was classified a "heavy anti-tank rifle", as well as a light AT gun.