My 177 S has always been very consistent, but I have struggled with accuracy. I have messed around with different taps and shimming options to get the alignment as good as I can, pushed pellets through to check engagement with the rifling, all sorts over the years. My conclusion is that its very hold sensitive. I have found that if I rest it on my front hand it will group very well with JSB 4.53 which also give good power as they have a fairly wide skirt and sit high up in the tap. If a tap is aligned correctly then the transition to the barrel should not be that bad for the pellet. More like a smooth section of barrel before it hits the rifling. The pellets in a lot of mag fed rifles probably go through worse.