Tried some .25 Predator Polymags without the tip today.

Good test...Nevertheless, the aerodynamics of the pellet are usually destroyed when you remove the poly-carbonate tip and you will loose your accuracy at longer ranges...

Try Wadcutters or Hollowpoints instead...I personally would use Hollowpoints...Wadcutters are excellent at short distances but not accurate/efficient at longer distances.

In 25 caliber I would suggest you try these H&N Barracuda Hollowpoints, very accurate and you get the same NO PENETRATION - MAX EXPANSION effect that you are looking for while keeping long rage accuracy: http://www.pyramydair.com/s/p/H_N_Baracuda_Hunter_Extreme_Pellets_25_Cal_28_4_Grains_Hollowpoint_200ct/1048

Regards,

AZ
 
Yeah, its for short range only, but they go a lot better than the RWS Super-H-Point (not usable at all in my MKII Bobcat)
I shot a mag of Super-H-Point (11 pellets) at 26m (28.5 yards), not one direct hit on the plasticine target :D

I did get some H&N Baracuda Hunter pellets a few days ago, looks promising at 50 yards.
I have yet to test them on plasticine (if anyone wants me to)