The older Nosler reloading manuals had a method that only required a bullet, a cleaning rod, and a fine point sharpie. It's simple, easy, and understandable. I haven't looked to see if the technique is in the newest manua
- Close the bolt
- Run the rod, with the solid patch pushing jag, into the barrel as far as it will go
- holding the rod against the bolt face, mark the cleaning rod at the precise end of the barrel with the Sharpie.
- remove rod and bolt and drop a bullet (sharp point forward) in the barrel till it lodges against the lands. Tap the back of the bullet lightly with the rod, so the bullet will stick in the lands.
- Run the rod into the barrel gently till it reaches the tip of the bullet, and while holding it in place, mark the rod with the sharpie, at the precise end of the barrel.
- The distance between the sharpie marks is the cartridge OAL that will touch the lands.
- now you can set your bullet seater die to seat to, or just off, the lands.
Be sure you have a flat faced tip on the cleaning rod for both measurements or the tip of the bullet will enter the open end of the rod and give you a bad measurement. Also, dropping the bullet into the chamber so that it reaches the lands can, with some rifles, be frustratingly difficult. I take a wooden pencil, double up some tape, stick it to the eraser, and stick the bullet base to the tape and use that way to put the bullet against the lands.
The method works fine, unless you need the absolute umpteenth in precision of measurement. And unless you don't have a fine point Sharpie, you don't need to buy anything.