I shoot low power so anything over 10.5gr leaves the barrel like a moody teenager.
best accuracy at 30 yards is the 8.4grn jsb shorts, aa Diablo fields and jsb 10.4 heavies not far behind. At 50 yards the AA Diablo fields have the edge and at 100 the AA Diablo are considerably better. 40mm spinner not much of a challenge
I find my barrel to be very dirty, it needs cleaning every tin of pellets, I have just given it a good polish hopefully this will help a little.
my groups are very similar to Hoytwon,
30 yards with AA Diablo fields 38 shots
.
At 50 yards the groups open a little but still good.
I have shot about 3-4 thousand pellets through mine now, I have done some upgrades to the internals to make it smoother/better but it is still not up to the standard I am totally happy with, I will be fitting a LW barrel to mine in the near future as I am not 100% convinced by the stx barrel liner system at the power levels I shot at. At higher power levels it may be totally different.
I am sure my impact has some serious potential but i need to do more work and pellet testing to find the state of tune where is matches my other guns in terms of accuracy and consistency.
Bb