I am fairly new to rifle reloading and it amazes me at how much is involved with loading rifle ammo. A little info before my advice. I use a Lee single stage press with Lee dies and load 223 ammo. I offered to load some 45-70 for a friend that acquired a set of Lee dies, 100 cases and 100 Hornady bullets with a gun he bought. I looked around at some recipes and gave him a choice on some powder and I picked up some primers. Now for the advice....READ ALL INSTRUCTIONS THAT COME WITH THE DIE SETS BEFORE USING!!!! Rookie mistake on my part!!! The instructions for the Lee die set I have for my 223 says when installing the seating die, screw the die in until it contacts the shell holder on the ram then a 1/4 turn tighter and tighten the locking ring...says it right there in the instructions. The mistake I made was I "ASSUMED" that it would be the same set up for the 45-70 seating die seeing how it is a Lee Die in a Lee press, boy was I wrong! I disregarded the instructions and set it up the same as my 223 die and went to seat the bullet in the first case. i would press a little then measure and adjust, press a little more measure and adjust. I was getting closer to the COAL and adjusted again and as I pulled the handle and applied a little extra pressure to my amazement I now have a case that looks like an accordion in the middle. I decided I should read the instructions and they said to put an empty case in the shell holder, pull the handle to extend the ram, screw the die in until it first makes contact with the case then set the locking ring(I backed off just a smidge after it touched the case)...and adjust the seat accordingly. Next one loaded and seated was beautiful right off the press. So pretty cut and dry, read the instructions, even if it is the same brand die in the same brand press...don't make the same rookie mistake I did by "ASSUMING"!!!