"Accuracy of HE. Shells" Topic

I'm reassessing the way to handle direct firing of HE shells, primarily firing at vehicle targets. Right now I add +1 when firing at moving targets. I'm thinking of adding +1 for all HE shells.
One thing I found is that HE shells do not have tracers so are difficult to determine the trajectory of non-hits. Thus correcting aim is somewhat difficult.

Now the link below gives advice that hits from HE shells can do damage to tanks. But, it fails to mention that it is harder to hit with HE shells.
link

It was reported by Germans that captured 75mm French guns when using captured Polish AP shells consumed unusual high numbers of shells trying to hit tank targets in Russia. The Polish Anti-tank shells had no tracers.

Also, the first German 75mm HEAT shell (HL) used a re-purposed HE shell casing which also didn't have a tracer. Later HEAT shells added tracers.

It is the direct fire drills and skills of the crew that should be taken in to account more than the ammunition.

The ammunition would come in to effect when hitting the target, but until it hits, it wouldn't have much bearing on the results.

To do direct fire you first have to guess the range (if not known) apply a bearing and elevation to the equipment, whch is then adjusted accordingly after each shot.

Sure, some tracer would help to follow the round to the target (and make it easier for the target to see where it was coming from), but you still need to apply a new bearing and elevation each time regardless.

Unless the French guns and the Polish ammo were designed to be used with each other they would have a reduced effectiveness. If perfect obturation is not obtained, or the driving band isn't fully engaged as the round travels through the barrel, then you will have a lot of inaccuracy.

This is speaking as a gunner that has done direct fire.

which is then adjusted accordingly after each shot.

Adjust according to what?

Adjusted to how far it missed, e.g if you have missed by 50m left, the next shot will be fired 50m right. This is very simplistic, let me know if you want more info. I'm assuming you are talking about HE fired from AT guns against armour, HE indirect is another world entirely, but I was an MFC for about 10 years.

Yep, what foxweasel said.

the fall of shot is observed and the gun needs to be adjusted via the bearing and elevation hand wheels to bring the barrel on to the target based on where the previous round landed.

Bearing = left or right
Elevatoin = up or down (fell past the target or fell short of the target)

As noted above, HE shells are relatively easy to correct as they make a great big bang when they hit something. Unlike AP shells which don't (and for which tracer may be helpful).

They of course often have different ballistic characteristics, but that is more of a sighting issue.

I was reading some accounts of the early Eastern front recently, and I was surprised how often the Germans successfully used HE to disable KVs etc by blowing the tracks off with direct fire.

I'd leave accuracy vs tanks the same. As others said, while you may not have a tracer, you do get a big explosion so you can see how far you missed by. Don Featherstone said that the first shot usually missed at any range but the second shot had a high probability of hitting the target. He did not specify ammo. Also of note, when firing HE at an armored target, you need a direct hit, like with armor piercing, to get an effect.

While it does make an explosion when it hits that is not a point to adjust from but a large cloud. Also if it is high the shell carry another 100-300 meters beyond and then be at ground level when it goes off so the distance wouldn't be discernible. The gunner would have to bracket and drop the range down 200-400 meters like they would if at sea and ranging with splashes.

Actually, this becomes one of those 'Rules tells a Story' type things where the author can add his opinion to the rules.

Did all WW2 anti-tank rounds have tracer?

Like I mentioned I found that the 75mm Polish AP shell and the earliest German HEAT shell HL didn't have them.

Based on reading various references, tracers were more important with the higher velocity AT guns. With their flatter trajectories and the lack of an explosion tracking their flight made them necessary.

Particularly as range estimation was less critical with high velocity rounds and observing the lateral error of more importance.

But then, that is just based on references or histories.

With the higher trajectory of HE rounds, range estimation is more important and line can be determined by the impact explosion.

All of this is, in my view, of more importance when firing at a moving target or one at longer ranges.

Crew training and familiarity with the weapon indeed have more influence than the type of ammunition. US Rangers had 75mm on half tracks for D-Day, they trained and were able to put shells through bunker embrasures regularly…..

Weasel,
Yes, from what I've found almost all WWII AP rounds did have a tracer. Exceptions maybe pre-war rounds.

Mobius,
I could not really find anything about tanks crews having specific problems firing HE rounds without tracers. The Germans did have a HEAT round for the 105mm gun that has a tracer element. I found diagrams of the German 75mm Gr. 38 HL/C and 88mm Gr. 39 HL (later war rounds) did have a tracer element. They could also be used as HE against unarmored targets.

There is an account in Michael Green's book "Tiger Tanks" on Page 32 about a US Sherman in Tunisia that surprises a German 88 on it's flank. The Sherman TC estimated the range at 800 yards, and missed. Corrected to 600 yards, another miss. Meanwhile the 88 is laying the gun on his tank and he corrects to 400 yards. The round knocks out the 88 just after it got off a shot (Snap Shot?) and barely missed him. Evidently the TC was able to observe and correct at 400 yards about .3 seconds TOF. It was probably the M48 HE round which from my checking did not have a tracer element but it appears at least in this engagement the TC was able to observe and correct. As you know, one engagement does not qualify for establishing a standard.

An AT gun kicking up a lot of dust could obscure the round without a tracer.

I shoot an M1 Garand at 600 yards (iron sights) and can spot the vapor trail of the 30-06 round at about 400 yards and walk it into the bulls eye at 600 yards with a 10x spotting scope. I'd think it would be fairly easy for an unbuttoned TC with 6x binoculars to spot a 75mm round without a tracer out to about 1 second TOF without much of a problem but have never tried it (not sure if it would leave a vapor trail to spot being slower than a 30-06). If the rounds goes to the left or right of the target it would be fairly hard to determine an under or over just like naval gunfire.

I also remember being able to watch 81mm mortar rounds with the naked eye on their way up and down too.

I guess the big question is could the AT gun spotter see the shell or vapor trail in flight to correct or not? Evidently not because the Germans noted it took 10-12 rounds to KO a tank with the French gun and no tracer.

Wolfhag

OOps!

FWIW the diagrams of the German 75mm Gr. 38 HL/C and 88mm Gr. 39 HL (later war rounds) that show a tracer element are Allied drawings and I think they may be wrong. The German diagrams do not show a tracer.

Wolfhag

There was a discussion on the Axis History forum about the 75mm HL shells. Also posted with photo cut-aways of 75mm HL/A, HL/B and HL/C with tracer. Not so with the earliest one the HL.

As foxweasle and Shelldrake said. You adjust fire based on the first round/salvo, etc., … the fall of shot …

The old story was if shells landed behind your position.

Then in front of you position.

You've been bracketed.

The next rounds will be on target … you.

Legion 4,
I think Mobius has a handle on the process. I think his challenge is how do you modify shots to bracket when you don't know where the last one went.

Wolfhag

Correcting fall of shot when firing HE is relatively simple even if the round is not seen. In this case it has usually gone beyond the target and probably fallen in dead ground. This is caused by incorrect estimation of range, so make a bold correction i.e. drop 400, and fire again. Once you've seen a round land you can then adjust onto the target. This is the method we use for adjusting mortar fire and I would think a similar method is used for artillery or when firing HE from tanks.

I agree Wolfhag … I was just adding a little context …

Wasn't there something on an introduction to a US modern manual that stated that it took and average of 13 shots to hit with a WWII Sherman? So they are probably bracketing.

Legion,
I know, I'm guilty of supplying "color commentary" on multiple occasions. I just wanted to bump the discussion because I'm curious about this situation too.

Mobius, IIRC the 13 rounds to get a hit is in the intro of a tank manual but does not supply any details about ranges, errors, practice, combat, etc. Personally I disregard it as I have not come across any AAR's or personal accounts of that happening. If it were SOP in WWII the Allies would just be arriving at the Siegfried Line.

If you bore sighted that French AT gun you'd expect a 75% chance to hit on the first round at 300-400 meters on a 2 meter high target. Typically gunners would continue firing at targets until they saw flames or crew bailing out. If it did take 10-12 rounds to KO a tank at least half of them may have been hits, we just don't know.

The problem I see about the verifying the number of rounds to KO a tank is you don't really know what rounds were effective and which ones were overkill and counting is done after the battle. In the video of the Pershing vs the Panther in Cologne the Pershing gunner hit at about 50m and then fired two more rounds into the Panther when it was clear the tank was on fire and crew bailing out. After the war the gunner was questioned about putting two additional rounds into the Panther. He responded by stating that the Panther had his gun pointed at him and he was not taking any chances.

I think the tank manual states precision fire / bracketing is used for all round types if the ranging shot missed unless using the Battle Sight / Burst on Target method which is typical at targets out to about one second TOF but for that the gunner must sense the tracer or result, that's harder for an AT gun.

Wolfhag

Totally agree with Wolfhag on the question of "rpt" (rounds per tank) – far too many variable conditions to justify any attempt to identify a single relevant value. Taking just one example – the Italo-German defense of Point 104 in the Desert Campaign. It was a dug-in and well prepared position with the ranges along all likely avenues of approach pre-measured and marked with white-painted stones.

B

Wolfhag is correct, bracketing was used for all ammunition types at anything but short range. 1st round hits/kills are only found in hollywood and on the wargames table. (German propaganda claims notwithstanding)

And as tech and training evolved, like today. The 1st round kill became more of a reality. If any tank took 13 rounds to hit/kill a target today. It would probably be equipment malfunction/failure before it would be gunner error. Probably …

No Tank Cdrs I knew would stand for 13 shots to hit/kill a target. But again, WWII and Korea did not have the tech nor training for tanks and their crews as there is today. Or even a few decades ago. When I had been attached to Tank units, in the mid-late '80s.

The single largest source of missed targets when shooting at unknown ranges is range estimation error.

Modern laser-rangefinder fire control systems basically eliminate this.

Yes … tech does make things more accurate and in turn more effective, i.e. deadlier …