How to determine maximum cartridge length.
What you need:
• Cleaning rod (plastic-coated preferred)
• Sharp-point felt tip pen
• Accurate measuring device
How to do it:
• Make sure the rifle is unloaded.
• #### the bolt and close it, so that the firing pin is retracted.
• Insert the cleaning rod from the muzzle end, until it stops against the bolt face.
• Holding it tight against the bolt face, make a mark with a sharp felt-tipped pen on the rod.
• Remove the rod and set aside.
• Open the bolt and remove from the rifle.
• Take an unloaded bullet (not a cartridge, bullet only) and drop it into the chamber, so that it stops against the lands of the barrel.
• Use a pencil or other short object (wooden dowel, screwdriver) and press the bullet tight against the lands and hold it there with one hand.
• With the other hand (or get help if needed) insert the cleaning rod from the muzzle end until it stops against the bullet, without pushing the bullet away from the lands.
• Make a mark on the rod with your felt-tipped pen.
• Accurately measure the distance between the 2 marks on the rod.
• This distance is your maximum loaded cartridge length for the bullet used, in your rifle’s chamber.
• Subtract 1 millimeter (~1/16 inch) from this length for the optimum cartridge length.
• If you switch to a different bullet, repeat this process for the new bullet.
• For some older rifles with long leads (ledes?), this determined maximum cartridge length may be too long to fit the magazine box and the max. length will have to be adjusted accordingly.
