I'd take that lee die, clean it well, pull the seater plug and walk outside and throw it as far as you can. You never know when you will be able to use a seater for a project, but the die itself is too hard to turn into anything else and you may as well get rid of it unless you enjoy chasing your tail. Hornady makes a good die as does CH4D, Redding is a bit pricey but good too. Lee, well you get what you pay for. The sizing die should be fine and the powder through expander, calling it okay will be enough, the seat die is pretty much junk. Now if you persist on keeping it, if you'll get a universal expansion die either the Lyman M type or any of the other company's and expand the brass to the point the the neck rides up the inside of the die that should keep it straight fairly well (used that trick in the past) the problem is that you are overworking the heck out of the brass and it will not last as long (cover my butt here since I don't know how long you've loaded, I did not mean to open up the neck to size of the body, just enough so as soon as it enters the part of the die where the neck is; that the expanded brass rides on it 360 degrees) once seated then use the FCD die or go back with the seater die and use it to crimp and size the case back down. With Lee dies and bottleneck cases you MUST do it in two steps, it will cause a lot less headaches.
