I am new to reloading and was trying to measure the lands of my rifle. It is a 721 300H&H. I used the cleaning rod and marked it and measured the marks and got 3.724 but all the reloading books say the col 3.600. how do i know if my bullet is in the rifleing. I loaded an empty case and bullet to 3.700 and the bolt shut fine and wasnt hard to close. any ideas would be helpful.