We are getting a T-34 85... so what tank gun of the tanks is best?

[Motherland]

Ya mean that ... right now... we dont have an accurate gun sight???    Sometimes I wish that HTC would accept help from volunteers to help devise and code some of the little things that could and would help the game along.  I can only imagine there would be an army of coding volunteers if they openned up.  Everything from fixing gun sights to improving graphics, to researching stats, facts, and testimony of the planes and vehicles in the AH2 game.

We already see that with maps and skin, which are all player created (including most of the default textures).
However, I, and apparently HTC as well, think letting players get into the coding may be going a bit too far.

[TDeacon]

All,

I have created a Wish List thread for adding an Assault Gun to the game, along with an outline as to why this might lead to interesting gameplay options.  Serious and thoughtful comments are solicited. 

Go here:  http://bbs.hitechcreations.com/smf/index.php/topic,243156.0.html

[Iron_Cross]

This has nothing to so with acceleration. Penetration is a function of either energy, or momentum. What you're describing is momentum, which usually is a poor substitute for kinetic energy when it comes to penetration.
SNIP

You are right this has nothing to do with acceleration.  As soon as the projectile leaves the barrel it ceases to accelerate.  The powder can no longer impart kinetic energy and momentum to the projectile.  The Russians could not get the energy, so they compensated by upping momentum.  I was trying to get that through to the people who think just because it is similar in caliber to the German Flak 36 L/56, and British 17lb, that it will perform as uber as they are.

As far as your little example.  Try sending both projectiles through 3" barrels.  The 9mm will bounce off too, but the .45 will still put the perp on his butt.

[Cthulhu]

You are right this has nothing to do with acceleration.  As soon as the projectile leaves the barrel it ceases to accelerate.  The powder can no longer impart kinetic energy and momentum to the projectile.  The Russians could not get the energy, so they compensated by upping momentum.  I was trying to get that through to the people who think just because it is similar in caliber to the German Flak 36 L/56, and British 17lb, that it will perform as uber as they are.

As far as your little example.  Try sending both projectiles through 3" barrels.  The 9mm will bounce off too, but the .45 will still put the perp on his butt.

True, .45 definitely has more knock down power (courtesy of that momentum), but I was talking about penetration of armor. Totally different animal. I could get into strain rate and speed of plastic deformation of the armor, but that would probably bore this crowd.

Wait.. I think it already did.

[*PAPA*]

Penetration of a tank round is dependant on ballistic coefficient (mass, surface area, and drag) and velocity. I don't even know why "momentum" is even being discussed here as it's not in the equation.

[633DH98]

Momentum (p)=mass(m) * velocity(v)

[Squire]

The Russian 85mm shell was a 21.5 lb shot with a muzzle velocity of 899 m/s. The energy of the round leaving the barrell was on par with both the 17 Pounder, and the 88 L/56.

Armor Peircing Capped Ballistic Cap (APCBC) shell for all three guns in meters per second:

85mm: 21.5 lb at 899 m/s
17 Pounder: 17.0 lb at 884 m/s
88 L/56 (Tiger I): 22.25 lb at 811 m/s

It was the quality of the shell that decreased its performance. A problem that persisted through the war for the Russians, although the shells were certainly "good enough" in most cases to get the job done, and the Russians did develop APCR (tungsten) rounds for their T-34/76 and T-34/85 to help with penetration.

[Cthulhu]

Penetration of a tank round is dependant on ballistic coefficient (mass, surface area, and drag) and velocity. I don't even know why "momentum" is even being discussed here as it's not in the equation.

It has nothing to do with surface area or drag. Has everything to do with mass, sectional density, modulus and strength of the penetrator material and the target material, and impact velocity. Both energy and momentum are dictated by the mass and impact velocity. (Thanks 633DH98 ) This is generally referred to as "terminal ballistics".

What you're talking about is "flight ballistics", which will allow you to calculate the appropriate elevation to hit the target at a given range, but it won't tell you if you're going to kill the target.

Just for grins, I went out and found a link to one of our older programs here at Lockheed.

http://en.wikipedia.org/wiki/MGM-166_LOSAT

Scroll down close to the bottom where it says:
"Video of LOSAT in action"  (5000 fps Baby! )

The missile was later downsized because it was too lethal.

[wulfie]

I actually spent a lot of time on subjects like this long ago, in a a different life. This including talking to Veterans (German, Russian, American, British) that actually crewed these vehicles in combat.

For armor penetration:

1. 17 pdr. This gun has armor penetration roughly equal to the 75L70 of the Pz V. This is with APCBC. The 17 pdr. also used discarding sabot rounds in combat, which were not overly common but they were available (a few rounds of the total loadout) and this increased the penetration by about 50% overall.

2. 88L56 (The Pz VIE/Tiger I MA). APCR was available for this gun, but was fairly rare. It was also very nasty. 88L56 APCR hit as hard as 88L71 (that's the gun the Pz VIB and JPz V carried) APCBC. By 'rare', we're talking 1 or 2 rounds per vehicle, to be used only in the event that something really dangerous came along that 88L56 APCBC could not handle (there weren't a lot of Allied MBTs in this category, ever).

3. 88L53 (T-34/85), 75L48 (Pz IVH), 76L55 (M4). With 'standard' APCBC, these guns all have almost equal penetration (read below).

4. 76L41 (T-34).

There are a few things to remember.

Solid AP has an increased chance of 'shot shatter' if the round is impacting armor plate that is thicker (this includes 'effective thickness' due to sloping) than the diameter of the shot. This explains why there are situations where the 88L53 could be more lethal against certain types/thickness of armor plate than the 76L55 even if the 'base penetration data' is very similar. It is also partly why tungsten core rounds came into being, and why depleted uranium rounds exist today - high to ultra-high velocity rounds penetrate better and are less likely to shatter against hardened plate when they are made of dense material.

http://www.freeweb.hu/gva/index.html - I cannot stress how excellent this site/info is regarding the topic at hand. Go and read every page of this site if you are interested in gun and armor data from WW2. It explains in detail the various factors - round type, armor type, thickness, etc. For a very solid basic understanding of the topic, read this site several times. It is an excellent resource. Probably the best collection of data and explanations to be found in 1 place in any book and on the internet.

Mike/Wulfie

edit: added the '0' that I forgot.

[Squire]

"and this increased the penetration by about 5% overall"

Umm, I think you forgot a 0 on the end.

17 Pounder stats:

500 meters (APCBC): 180mm at 0 degrees.

500 meters (APDS): 259mm at 0 degrees.

The 17 Pounder APDS round was an extrordinarily powerfull shot, the forerunner of modern APDS tank rounds. It was the most lethal 76mm round used in WW2. The Fireflys only carried a few rounds per tank however. 

[wulfie]

in my eyes i think the 85 is match for the tiger and vice-versa but the winner will be the person who sees the other one first

The Tiger can almost always survive a frontal turret hit from the T-34/85. A frontal hull hit and the chance of a penetration at 500m is close to 50%.

Going the other way, the Tiger will almost always kill the T-34/85 with a frontal hit (turret or hull) at 1000m.

Then there is the optics issues - German gunsights were of superior make and superior design (in terms of ease of use and first shot hit probability) when compared to Russian ones. There have been some sims that accurately modeled the different sights, including sight controls, etc. and in those situations the importance of the differences becomes very evident.

http://www.freeweb.hu/gva/index.html - go there and look at the armor and gun of both vehicles.

I talked to one T-34/85 Crewman a long time ago and he commented that most Russian MBT crews liked the T-34/85 the best of all the Russian MBTs (including the Is-2). Good turret rotation rate (they fought their Is-2s like assault guns because the rotation rate was so poor), great mobility, a good gun (they could trade shots with StuG IIIGs and Pz IVHs as rough equals) and most important of all - the T-34/85 had the ability to 'pop smoke'. According to the Russian crewmen I interviewed, this was very important..."Because if the Germans missed on the first shot they never missed on the second". Smoke gave them a chance in open terrain at range.

Mike/Wulfie

[wulfie]

Umm, I think you forgot a 0 on the end. 

Yeah I did. LOL. Thanks for catching that, thanks for the heads up, etc.

Mike/wulfie