I would keep the same bullet but ditch the pellets . Go to loose powder . Start around 90 gr and go up in 10 gr increments til you find the sweet spot . I would be willing to bet 110 to 120 gr 777 or 90 to 110 gr Blackhorn would improve your groups but you just need to work up the best load and see . Good luck . If you shoot trie 7 swab after every shot .