I shot these pellets last year in my FX 500. Velocity was 1040 fps if I remember correctly. They shot very well at that speed but were a little more wind sensitave than the 25.4 grain. The 25 grain GTO's are 16 grain I think. At 1040 fps it was like shooting a sub sonic 22 long rifle. I shot some pigeons at 70 yards plus and they were DRT. I still have a few and will shot them in February in Arizona.