using 30-50mm vs better then standard protected IFV (SPz Puma, Namer, BMPT-64) is pointless -all of them have protection better (for +/-30.) then penetration values - even for telescopic munition. So there is no nececcery to use bigger then 40mm gun.
And programated air-burst effects (like in SPz Puma) is better idea then using low-pressure 100mm gun, and have no space for infanty inside. In fact modern heavy INF will be able to destroy for +/-30. only by ATGMs.
Thats the reson why on Puma is "only" 30mm + 2x Spike ATGM's - but germans tested double caliber 30/50mm canon for never-exist Marder-2. For the other hand - IFV ussaly in NATO doctrine cooperate whit MBT's.
for refresh:
Protection was mentioned in two articles in Polish mlitary special press:
1) Thomas Meauter, Puma - niemiecka platwiorma bojowa przyszłości, RAPORT-wto 04/2004, s.46-48
[Thomas Meauter, Puma - germans future combat platform, RAPORT-wto 04/2004, s.46-48 ]
2) Wojciech Åuczak, Puma siÄ™ ujawnia, RAORT-wto, 1/2006, s.44-47
[Wojciech Åuczak, Puma's appear, RAORT-wto, 1/2006, s.44-47]
Abstract:
In level (A) - 31,45t:
- whole IFV protected against 14,5mm ("anti armour" round - like 14,5mm BS)
- front (in +/-30.) SPz Puma protected against at least newest 30mm APFSDS, and HEAT warhead like in "RPG-7/18, SPG-9", glastic plate (upper and lower front hull have bigger protection - the same like in level "C")
- bottom hull protected against at leat 10kg exsplosive under
In level(C) - 40,7t. (with crew, ammo, etc -43,5t)
- front IFV (+/-30.) protected against APFSDS "middle caliber" (~40-60mm APFSDS) and the latest RPG warhead
- side hull protection against RPG warhead (HEAT) (for +/-30.?) and EFP and 30mm APFSDS.
- roof protected against bomblets, cluster munitions, etc.
It's look that SPz Puma have in fornt (in A and C level) protection like ~220mm RHA against APFSDS and ~600mm vs HEAT.