Scott,
I used my Lyman 450 to seat the gas checks on powder coated 55-grain RCBS 22 bullets. However, I used two top punches one in the lubri-sizer like normal and the other simply pushed into the sizing die with the flat end upward. the top punch aligns the bullet and the other acts like a pedestal. You set the gas check on the pedestal and bring the top punch down to seat the gas check. Nice flat surface to work on and plenty of room even for big fingers.
