Instead of the M die, try the Lee Neck Expander. It comes with 2-3 tapered inserts that you adjust in your press to get a nice, slightly tapered neck. Just taper enough to allow the base to insert easily and you're good to go. I've used mine for 30-303-35-45 cal's . Nice tool cheap and all calibers in 1 box.
Those are ok but I had bullets being swaged when using that lee die. Threw it in the garbage as it is useless. A M-Die enlarges the whole neck so there is no bullet swaging happening at all. A lot better design then that $0.75 lee die.
Instead of the M die, try the Lee Neck Expander. It comes with 2-3 tapered inserts that you adjust in your press to get a nice, slightly tapered neck. Just taper enough to allow the base to insert easily and you're good to go. I've used mine for 30-303-35-45 cal's . Nice tool cheap and all calibers in 1 box.
Shouldn't have thrown it out, NOE makes some excellent expander plugs that screw onto the Lee Universal Neck Expanding Die. The expander plugs are less than $10 each, whereas a Lyman M die is +/- $25 for each caliber. So You can have just one LEE die and with an assortment of expander plug sizes for a very reasonable price and a greater variety of expander plug sizes to choose from.



























