Why did you change the bit in 1st place? Any particular reason? What bit do you use now (pics)?
I'd suggest trying eggbutt - it's very smooth and shouldn't cause any pinching or rubbing in corner of the mouth (I got eggbutt/loose ring combo for my paint just recently, and my qh goes in eggbutt since day 1).
"Life isn't about waiting for the storm to pass: it's about learning to dance in the rain..."
"When we are no longer able to change a situation - we are challenged to change ourselves."
"How people treat you is their karma; how you react is yours."