I read that might be the case. I had 6 blanks prepped for assembly. I trimmed one of the other kits some (saw lots of brass shavings coming off the trimmer) and it was better, but still needs some more. I will likely need to trim the remainder blanks even more, turn them again so they are the correct diameter and refinish. Checked elsewhere and this seems to be a common problem.
Funny part is they mention to not over trim the blanks as this will cause issues, when it appears that is exactly what you need to do.