Posted 3 Months, 4 Weeks ago scottie Senior Boarder Posts: 45   Can someone please advise what is the maximum case length for the .300 Win. Mag.? Do you measure the length from the base (head) till the mouth of the neck? Thank you, The administrator has disabled public write access. Posted 3 Months, 4 Weeks ago angelusbe2004 Senior Boarder Posts: 53   Morris, According to my Speer manual #13 Maximum case length for 300 Winchester Magnum is 2.620' or 66.55mm. That measurement is taken from tip to tip (Bottom of rim to tip of mouth) TOTAL length. Good Luck The administrator has disabled public write access.