I'm new to casting my own bullets, so bear with me. I cast some Lyman 311291 boolits 170g with gas checks. They will not chamber in my M1917 or in my M1903 National Match rifles. So I kept seating the boolit deeper. I've heard to "never seat below the bottom of the neck". Putting the gas check at the bottom of the neck yields an OAL of 3.032"
Do I seat the boolit deeper or am I doing something else wrong?