I just received RB model's metal barrel for bronco's German 88mm flak 41. The barrel basically full length, reaching all the way to the breech block.

This gun is supposedly the same caliber and same barrel length (71 calibers.) as then kwk43 gun on the tiger II, jagdpanther and nashorn. But comparing this barrel side by side with dragon's metal barrel for the nashorn, which also reaches all the way to the breechblock, I was amazed to find that the RB model barrel was substantially longer, by almost half an inch. Further,ore the back part of the barrel if also substantially thicker.

Now we're those two gun barrels actually that different in length and thickness?

I am willing to believe the flak gun barrel could be slightly longer because tank guns were often designed with a shorter but fatter chamber, which allows the cartridge case to also be fatter but shorter, making the round more handy to handle in the confined spaces of an armored vehicle. But half and inch would scale out to almost 18 inches in real life. Are flak 41 and Kwk 88 barrels really that different in length despite both being nominally 71 calibers long?

Was the wall of the flak gun barrel really substantially thicker than the wall of the tank gun?

I was under the impression the tank gun was basically derived from the AA gun.

The 8.8 cm Flak 41 wasn't the basis for any tank guns. Further development of the 8.8 cm Gerat 42 led to the PaK 43 anti-tank gun, PaK 43/41, PaK 43/1, /2, /3 1nd KwK 43 tank gun. The FlaK 41 used an 85 5mm long cartridge; the PaK 43 guns used a cartridge which was 822 mm long.

Rounds for tank guns developed from FlaK weren't "fatter". The KwK 36, used on the Tiger I, fired the same exact ammunition as did the FlaK 18, 36 and 37 which was 88 x 571 mm.

So what is your answer to the main question?

Google is your friend.

You essentially answered your own question. If both barrels are 71 calibres in length, they are the same length. One wouldn't be longer or shorter than the other. in 1:35 scale, the barrel length is 178.51 mm. Again, the Flak 41 and KwK 43 are two separate weapons and have nothing in common other than overall length.

Don't use model kit barrels for dimensional comparisons. Here is a [1:10 drawing of the KwK 43. You can take measurements of the barrel thickness from the drawing:



The differences between Pak 43/1, /2, /3, /4 and KwK 43 were gun mounts,breech blocks (vertical or horizontal), position of the recoil buffers to fit in a particular vehicle and pinion mounts. Otherwise, it was the same gun.

I forgot:

Using 1:1 dimensions, measure the diameter of the barrel at any given point, subtract 88, divide the remainder by two and that will give you the approximate wall thickness at that particular point.

You're welcome.