I also have a Hoyt Ultramag ,and a 5 pin sidewinder. I have my sight housing down all the way except for half an inch or so. And I put my 20 toward the top and worked my way out to sixty. Still have roughly at least 5/8 of an inch till my bubble. I don't know what kind of rest you shoot but maybe it is to low? Just quessing. I don't know what else would cause this. Don't give up on it yet trying starting you pins more toward the top possibly look at you rest. Hopefully this may trigger something. Though this is just my opinion hopefully you figure it out I love everything about my ultramag setup it has been wonderful.