you might want to post this on one of the AR-15 forums in their reloading section.
What issues are you having? and are you trying to use a lee factory crimp die or just the roll crimp built into the die?
CPL holder since 1991, NRA Lifetime Member, DU Member, NICET certified
"For those who would give up essential liberty to purchase a little temporary safety, deserve neither Liberty nor safety.—Ben Franklin.”