sabot rounds on 7TP
 

Polish tank units 451 and 459 (7TP) have sabot rounds in 1939. Is that correct? I always thought that the Germans were the first to use it in 1940.

Mario

Re: sabot rounds on 7TP
 

If I still had my notes from 7 years ago I might be able to tell you exactly what it represents but I don't. What I do know is 9 years ago the 7TP did not have "sabot" and 7 years ago it did so it's not a mistake, it was deliberately added.

I will also draw your attention to MOBHack Help for information on "sabot" rounds


so ammo in that column can be anything but regular AP

Re: sabot rounds on 7TP
 

Definitely Poland had no improved AT rounds. There were used two types, APHE and AP-T, with similar weight and construction. Penetration 8 suggests some APCR, like German rounds. On the other hand, penetration of a basic round should be IMO improved - now it's 5, while according to a Polish source it penetrated vertical 60mm @ 300m (48mm @ 500 m) - seems it was slightly better, than Pak-35/36.

Michal

Re: sabot rounds on 7TP
 

So what is that "sabot round" they have?

Re: sabot rounds on 7TP
 

Something that they should not :smirk:

Re: sabot rounds on 7TP
 

Well if Blazej Ciepluch ever shows up on the forums again we can all ask him what it is as I'm fairly certain it was his addition.

I can take it out..... but --it was out---then it's in ---then it's out again--- style of OOB work really gets old after the third of fourth time around

ALSO there is a 37mm wz.36 L45 that is also on a L7P and it has 4AP pen... the 37mm wz.37 L45 has 5 AP pen and it's found on other L7Ps

Don

Re: sabot rounds on 7TP
 

Well, it's not my fault :smirk:
I have never found any mention about works on APCR for Polish Bofors 37mm - and surely such things weren't issued. Maybe it's similar case, as these wishlist-super-guns in SPMBT. I'll take a closer look at the Polish OOB in several months, anyway.

Michal Derela

Re: sabot rounds on 7TP
 

It was definitely added back in the DOS days due to lobbying from somebody, with data etc. Something tickles my lonely little brain cell about it.

The old conversations on the subject are probably somewhere buried deep in the obsolete Yahoo! discussion forums, but since I don't have a password for that any more I cant check it. (Nor would I want to troll through the old fluff there, I don't think it had a search function).

But as Don says, it is quite typical of OOB maintenance stuff, somebody randomly queries something done back in the prehistoric days and expects us to be able to instantly remember why the SDKFZ4321 has a left-handed cup holder fitted. Usually, our answer to that has to be along the lines of "we are just as clueless as you, mate"!;).

Andy

Re: sabot rounds on 7TP
 

IIRC "sabot" is sometimes used to represent rounds with very limited performance like the AP used in the French 37mm tank gun. Something about the performance of normal AP dropping off in a liniear fashion with range while sabot drops faster with range and thus is a better representation of a weak low velociy AP round that penetrates something at short range but not much at, say 500 meters.

Dont know if that is the reason?

The Germans were the first to use "sabot" in combat in the form of APCR in 1940, but experiments had been going on since the 1920ies, first with Gerlichs taper-bore hunting rifles, then with a cooperation between Larsen in Denmark, where Gerlich worked, and the French resulting in subcaliber rounds for the French 25mm anti-tank. Still experimental in 1940 and not issued, but IIRC the French shipped all their research to Britain and the US. Janacek in Czechslovakia also did some work on taper-bore guns, resulting in the Littlejohn adapter for the British 2-pdr later in the war. Don't know if the Poles ever worked on something similar, but they did experiment with some very powerfull rounds for their anti-tank rifles - IIRC they were full-caliber, though.

Re: sabot rounds on 7TP
 

A sabot round in WW2 is usually an APCR. Its book muzzle AP value is higher than the plain shot, but the sabot range is less than the plain shot's so the pull-down for range will happen faster. Later better-designed APCR ammo can have a longer sabot range, but it still will be less than the AP range due to the "shuttlecock" effect of firing a full bore round with a "skirt" of lightweight metal that slows it down faster.

With APDS the opposite will be true. APDS drops the sabot rather than carrying it (and its wind resistance acting on a lighter shell) all the way to the target.

However a sabot round can cover other AP ammo, usually of a greater muzzle penetration than the regular round. However the French 37 shortie was a special case where the HE range was average, but a "sabot" round of limited range C/F the HE range was used to cover the poorly performing AP without slugging its primary role of putting out little HE shells. otherwise either the HE range would have had to be abysmal, or the AP round would over-perform due to its matching the main gun range (which is used for AP and HE).

Sabot ammo uses the sabot AP value, and the sabot range is used to determine the pull-down factor for range.

AP, HEAT and HE use the regular gun range, and for AP it is that range that is used for the pull-down factor.

SP 101 as explained in the Mobhack help, the effects can of course be seen by running APCalc for various weapons.

Andy

Re: sabot rounds on 7TP
 

I never heard of any special AP ammunition to Polish 37mm cannons in '39. Not to mention sabot rounds.

Re: sabot rounds on 7TP
 

I've said it before, we've put it MOBHack on the weapons data page---------" NB-- Sabot is simply a second AP type with different max range and/or AP value"------ and I have no doubt I'm still going to be saying this 5 years from now......... "sabot" ammo can be anything from real sabot to a different kind of regular AP ammo. It could represent a newer type of sabot round and the ammo in the AP column could represent an older type of sabot round if sabot was all that was issue as "AP". ( that would be applicable only in MBT )

The last DOS version of the Polish OOB the 7TP did NOT have "sabot" ammo. A year and a half later the first Windows version did. I'm fairly certain who it was who provided that info but he hasn't posted on the forums for quite some time and the prevailing wisdom now is this is wrong. OK , fair enough but all that's been offered is variations on " I've never heard of this".

It *could* have been that he had info on some experimental shells and added it in..... IDK..... if could be that it was simply a mistake but the entire ammo count changed so that's less likely. ....it could be he just made it up for fun but I find that even less likely so there was some basis for him adding a "more advanced" AP round for that gun and not only add it but add more of it after November 1938-----but IDK. I could and probably will take it out which means every scenario and campaign using a 7TP built since 2006 will show errors and have to be rebuilt.. but hey...... I do that every release anyway but the fact remains SOMETHING caused him to add this "more advanced AP round" and it's really too bad we can't hear what he has to say on the matter before I pull it out.


Don

Re: sabot rounds on 7TP
 

We have several months to find out, I think. As I've said, I have never found any info on works on improved 37 mm AP rounds, while I'm interested in Polish armour for at least 25 years (and for 15 years I run a webpage about it), and I'm trying to track the news. Surely such ammo wasn't issued. Besides, there was no need for improved AP rounds, since standard round was enough to deal with all contemporary German and Soviet tanks (its performance was slightly better, then Pak-35/36). Penetration 8 is the same, as German tungsten APCR. Future Polish tanks were to be armed with 40-55 mm guns instead.

Michal

Re: sabot rounds on 7TP
 

"Problem" solved. I contacted Blaz, the "sabot" has been removed.


Don

Re: sabot rounds on 7TP
 

Just a little comment on the French 37mm L21 gun (SA18):

The round you have modeled as sabot (AP Pen 3) was in fact one of the first service APCR rounds for tank guns. The original AP round for that gun was a naval design dated to the 1800s (basically a simple steel shot) and had a much lower penetration, something like 10-15 mm at 100 meters (90 degrees).

Many countries which purchased the FT-17 after WW1 did not get the improved French ammo. Finnish tests of the original AP ammo showed that it was incapable of penetrating 10 mm armor quality plate at 100 meters and was therefore nearly useless even against lightly armored vehicles. The French seem to have realized that some time in the 1930s and went for the best possible AP round they could design for that gun, since they had it on so many of their light tanks. Muzzle velocity was 600 m/s, which was pretty impressive for that gun.