4K, Grief, SK-105 Kurassier, Patagon, and everything else based on them

[dy031101]

One thing about the SK-105 that confuses me the most is its main gun......

It is said that the turret of the SK-105 is derived from that of the AMX-13...... that I can see.  But is the main gun still the lower-powered French one, or did the Austrians somehow manage to fit a version of the L7 (or something compatible) into the turret?

Thanks in advance.

[Arc3371]

AFAIK its identical to the AMX-13 and EE-17

[Weaver]

It must be the smoothbore in the original version, because there's an -A3 upgrade whose principle feature is the M68 (105mm L7) gun. Don't know if they ever produced it though.

Nice family of vehicles: the troop carriers are extraordinarily low though. Good tactically, but I'm not sure how comfortable they are for extended periods. There were all sorts of unbuilt prototypes too, including ATGW vehicles and a SPAAG with the French VDA turret (2 x 20mm Giat, search radar plus optical fire control).

[dy031101]

Wikipedia (I know it's not the best source, but nothing else I can find in any way identified the gun other than calibre) states that the main gun of the SK-105 is a rifled gun......

Is there a more reliable source of info on French-made tank guns?  Thanks in advance.

[Weaver]

Sorry, my memory's at fault: the gun was always rifled, but initially it's AP round was fin-stabilised HEAT (which made me think it was a smoothbore) and it was later upgraded with a new APFSDS round. The -A3 model with the M68 gun is probably more powerful, and might also have advantages in ammo compatibility with other systems.

[rickshaw]

Sorry, my memory's at fault: the gun was always rifled, but initially it's AP round was fin-stabilised HEAT (which made me think it was a smoothbore) and it was later upgraded with a new APFSDS round. The -A3 model with the M68 gun is probably more powerful, and might also have advantages in ammo compatibility with other systems.

French 105mm guns fired the OPUS-G HEAT round which used a slipring running on ball bearings.  The round was fired from a rifled gun (as used in the 105mm AMX-13 and AMX-30 and Isherman, as well as the Kurassier).  The slipring decreased the spin imparted by the rifling to optimise the Monroe effect of the HEAT round while still imparting some degree of stability on its flight.  The 85mm RCL L35 "Carl Gustav" utilised a similar system but utilising a teflon slipring. Basically spin and HEAT don't mix very well,  The spin from a conventionally rifled gun decreases the penetration of the HEAT warhead significantly.