OK, I wasn't exactly sure where to start this topic. Anyway, I just got interested in armor, and a few things unavoidably came up. What happens if the tank gets hit, but the armor is not breached? The tremendous kinetic energy of the round, the heat, the sound - how does this effect the crew? What were the chances of survival if the hull did get breached? When you read about "this-and-this many tanks were destroyed" it's easy to forget that there were people inside. Is it a death-trap as I imagine, or does the crew have time/chance to get out? (It's not just about the modern armour - the "vintage" stuff, too.) How about HE rounds? ejecting some molten metal inside the hull does not seem very healthy to me...

Some accounts I've read of Brit crews in M4s were that the round (esp. AP) could and would pass through one side and out the other, not singeing a hair on the crew... That said, without their cans on they would've been deafened...Others (ie. commander )have been blown clean out of the turret, quite a distance only to have survived... guess this hints at the high pressure from the heat/energy created inside the tank just begging to exit... Sorry but that's all I'd know
Cheers
Brad

In this case you might want to specify a time period. Modern stuff has been known to blow the turret off the tank, whereas WWII stuff the shot would oftentimes just bounce off. The common problem with more modern rounds is spall. Particles of armor will break of when a round penetrates and go zooming around the cabin at hundreds of feet per second. Bad for the crew if you know what I mean.

There's also the explosion of the high explosive which concusses inside the tank. The overpressure of the concussion can be fatal.

When I was a gunner (back in the mid-1970s) we fired HESH & HEAT rounds at target hulls and vertical sheets of armour so that we could see what the effects would be.
From the scabs of steel & jets of white hot metal that would be flying around the inside of the tank I wouldn't give much for the crews chances.
According to our instructors the aim was "minimum damage to the vehicle, maximum damage to the crew" - perhaps so that the vehicle could be recovered and returned to use?

From interiors I have seen, two things happen frequently... when there is a breach, gear and shards of metal (including bolts) go flying around like a grenade in a garbage can.... quite nasty.

Another common result in older WWI era tanks (through korea) was that molten liquid metal would simply spread a mist of heat inside the crew compartment, and often would "cook off" the interior ammo, if the stream hit the right places. This would often lead to a massive explosion with the turrent blown from the tank itself.... nasty results again.

In the newer tanks munitions of today, there are high velocity titanium shells that make a tiny hole--- but the pressure is enough to suck a boot through that small hole! Imagine what that would do to your guts and gear...

The real guru on modern armor would be Blaster76... he was a field officer in the armored calvary... he could probably share a lot more insight in both cases.

You're basically talking about the effects of two different approaches to "tank-busting". The old solid AP shot, the crew had some hope of survival, as if it passed through without hitting you, you ended up with a hell of a headache, & probably bleeding from the ears, but still breathing. Presumably some crewmen who weren't actually hit died anyway due to what Napoleonic sailors would know as "breath of the shot". There were cases of 88mm solid shot passing in one side & out the other of British cruiser tanks in the Desert without hitting anything vital, this was due to the thinness of the armour. However Matildas that were hit the crew were always killed, because the round lacked the kinetic energy to get out again, the armour being much thicker, so it just rattled around inside. I'm not sure if this was possible with an M4, depends on the range I suppose. There were tales of rounds going in the front & out the back (through the engine?!). If the round didn't penetrate, apart from being deafened (!), the crew would be unharmed (viz pictures of German armour after action with solid shot stuck in the armour, the usual "fix" was just to weld it in place!). The effect was described as similar to sticking your head inside a bell while someone rang it!
With the modern approach (HESH, HEAT, hollow charge whatever), the survival chances are slimmer, because they use the armour against itself, either burning through injecting a molten jet into the interior, or blowing off a "scab" which then rattles around inside. This technology was employed in WW2 in bazooka, PIAT & panzerfaust rounds, but against thick frontal armour they were unlikely to achieve a penetration.

BTW if you want to know more about this factor in WW2, I'm currently reading a book by George Forty (himself ex-RTR), Tank Warfare in WW2, full of crew reminiscenses from both sides.

The book Panzer Aces has many first hand discriptions of tanks that have taken hits. It is also a good read.