Gee revchuck, that is why the bullets I reload work well witht he same resizer in my XD but one out of 100 will not fit into my STI barrel. It gets jammed. I took the jammed ones and mic them and they are bigger than the rest. So I must be getting Glocked brass here and there mixed in and they are not getting sized all the way down. I never had this problem until I bought my STI. I now have the U die and wow what a difference. I sized a few brasses and mic them and there is no way anything can get by these dies. It sizes all the way down and they are small. So that makes sence what you say.