I am pretty new to reloading (1 1/2 yrs) and came across a problem last night...

I bought a new die set, Lee, and new brass, Winchester .257 Roberts +P, and tried to reload some ammo last night. When I seated the bullet to the recommended length the bullet would fall back into the casing. I even tried to crimp the bullet in place but it still just pushed right back into the casing. The question I have is what am I doing wrong?

Thanks for your help,
Ben

what die set?
full length, neck size or collet?
Dace

It was a full length sizer

I take it you are resizing new brass?
Adj the die untill it contacts the shell holder. turn it in about another 1/4 turn. try it there make sure the decapper is just punching through the bottom of te case. use some lube inside the case mouth so the expander is smooth. you can adj up or down fro there to get the desired size. you may want to remove the expander and check the size you never know when you might get one thats a little oversize.
DAVE

I will try adjusting the decapper/sizer and see if that helps

Thanks,
ben