I was originally using the old design Bis Mags with the lines running down the sides which were around 10.6 gr.
When these ran out I tried the 10.3 gr Barracuda Hunter as my barrel likes a long pellet. I find them very accurate and hard hitting for rabbits out to 45 yards.
At RTs recommendation I have just bought some JSB Exact "Heavies" which are also 10.3 gr. I'll be testing these later in the week.
Cheers
Matty