Great question. I haven`t tried over 100 gr FFG in my Sidekick. Next time to the range, I am going to load her uo to 150grains. I dought it will do any good, unless you are using very heavy conicals, I think with light roundballs and ball-ets, you probably have diminishing returns and lots of unburnt powder. Now that I think about it, maybe 150 gr of loose FFG is too much for it to handle, not sure. To be honest, the highest I have ever used in any muzzleloader is 120 gr and that was with a roundball in a T/C Renegade. I have found not long after 100 gr you don`t gain much in light bullets, the powder just doesn`t burn that thoroughly. 90-100 gr is very powerfull and accurate with most projectiles. I also like the look of the Sidekick better, shorter receiver and longer fore stock. Very comfortable and sweet trigger, very accurate. Jack.