How to measure your rifle’s seating depth.


Step 1: Insert the bullet into the neck of the fired case.  It should fall freely into the case with no resistance. 

 

Step 2: Remove the bullet from the fired case and press the case neck lightly against a flat surface to create a small indentation in the case neck so that it will grip the bullet.

 

Step 3: Insert the bullet, base first into the case so that the case just grips the bullet by itself. Just get the bullet started into the case, don’t seat it too deeply.

 

Step 4: Completely color the bullet with a felt marker.

 

Step 5: Gently insert the case and bullet into the chamber of the firearm and close the action.  Do not pull the trigger.

 

Step 6: Carefully open the action and gently remove the case.

 

Step 7: Retrieve the bullet. It will either be stuck in the lands of the barrel or still in the case. If the bullet is stick in the lands, it can be removed with a cleaning rod. If the bullet is still in the case, gently remove it with your fingers taking care not to mar the ink and proceed to step 8.

 

Step 8: During Step 5, the lands will have contacted the bullet and pushed it back into the case neck to scrape the ink off of the bearing surface of the bullet.  Simply push the bullet into the case until the edge of the case neck is just to where the ink has been scraped off.

 

Step 9: Carefully measure the overall length of the dummy cartridge. This overall length is called your “rifle seating” depth. It is where the bullet contacts the lands of the barrel.  This length is different for every type of bullet depending on ogive, meplat, etc. This process should be repeated three to four times to obtain a consistent average. 

 

Step 10: Set your seating die to seat at a depth between .015” and .03” less than your rifle seating depth.

  • When loading E-Tip® bullets, seating them .050” - .100” away from the lands typically produces the best accuracy. 
  • Lightweight bullets may need to be seated further from the rifling. A depth of one bullet diameter inside the case neck gives good neck tension for ignition.
  • The overall length must be short enough to function through the magazine.
Last update:
2013-10-31 22:58
Author:
John Bullet
Revision:
1.0
Average rating: 4.63 (8 Votes)

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