Posted by denny mcdaniels on May 23, 2025 in Rifle Cartridge Reloading
Writing by John Nosler on page 151 in the Nosler Reloading Manual Number ONE on how to determine at what point a bullet comes in contact with the rifling so maximum overall cartridge length. The only tools required is a set of calipers, empty unprimed case, the bullet that you wish to reload for, and a cleaning rod.
1-The first step is to insert a bullet through the chamber and make firm contact with the rifling. Then insert a ramrod from the muzzle all the way until it comes in contact with the bullet tip. Now mark the ramrod with a marker, this established the distance from the bullet to the muzzle.
2- Remove the bullet and close the bolt on an empty chamber. Again, insert a ramrod from the muzzle and have it rest on the bolt face. Mark this spot on the ramrod, the two markings represent the maximum overall cartridge length which allows the bullet to just contact the lands.
3- Assemble a dummy round (no powder and primer) to that length and test, you want to establish that this length will indeed allow the bolt to close and that no rifling marks appear on the bullet. If there is rifling marks, seat the bullet deeper. The end result is your max COL, from there experimenting is still advised to determine what is the best overall length for that bullet.