My son used some old kits that were here to make some pens for friends. He needed more and bought several styles from PSI. He noticed that the new kits had mechanisms that were hard to press in. Like very hard. All of them were that way and he worked around it by removing a bit from the diameter of the brass piece on the twist mech. Has anyone seen this or have any idea if we are doing something wrong? Or is there a brand of kit that is any better? He was using the tailstock to press them in. The difference between ID and OD was about 0.003".