I'm sorry to be the bearer of bad news but pointed pellets don't tend to do well at those distances.By far your best bet is with JSB or Air Arms in the 10.3gr weight, next would be the 10.6gr H&N Baracuda Match or if you're lucky you may find a batch of the Crosman 10.5gr Ultra Magnums to group well.Are you able to chronograph your rifle to see how fast it shoots a range of different weights? If energy fades when you step up to heavy pellets (compared to mid-weight 8.x grain pellets), generally that's a sign that the pellet is not matched well to the power plant.
Has anyone used the Skenco Golden Rod Long-Range Pellets in .177? I am looking for an accurate, longer range pellet for my Ignite Black Ops Gas Piston rifle... Not having good groups with the Gamo Red Fire or Crossman pointed out past 50 yards. (Maybe I need to go with a heavier pellet) Any suggestions or feedback would be appreciated!