I've found H&N Spitzkugels to be very accurate in my 3 .25s.Good luck!
I have a Hatsan Model 95 and Edge both in .25 that shoot right about 17fpe and an AirTact in .25 that shoots right at 20fpe with the JSB'sand why they were one I suggested. Hopefully one or even 2 of them will fit the bill for what you're looking for.Most of my shooting is 30 yards or less so the .25's (I also have .177, .20 and .22) work very well for short range pesting.