Cartridge Cases

Ambrose

September 05, 2014 11:26

I've been working with a new-to-me 7x64 rifle and bought a box of 50 Hornady cases. The local shop had a box of Remington cartridges so I got those, too. Loaded some of the Hornadys and shot them and some of the Remingtons, too. Out of curiosity, I weighed some of the cases. I was surprised to find the Remingtons weighed 204 gr. and the Hornadys, 184. Now, I've often heard cautions about reducing loads when using military brass since supposedly military brass is thicker and has less powder capacity but I don't recall 20 gr. difference in military vs. commercial in .30/06. 20 years ago, working with the similar .280, I was using Remington brass but acquired a couple boxes of Norma cases. Firing reloaded Norma cases alongside of Remingtons with the same load produced 80 to 110 fps less velocity per my Oehler depending on the load. Weighing the cases, the Normas were again 20 gr. lighter than the Remingtons. Probably no big deal, switching from heavier to lighter cases, you just lose 100 or so fps, but the reverse might create a nasty surprise! I know I'm going to do more case weighing from now on.

0

• 

  gunnut505

  September 06, 2014 18:45

  With a disparity of 20 grains, you need to fill a case with water, then weigh that.
  Try it with cases you've used for good accuracy, and compare the water weights.
  Easiest way to figure out how big the interior is without sectioning and running calipers all over them.

  0
• 

  jonk

  September 07, 2014 13:42

  What the last poster said is good advice. Point being: one case could have a lot thinner head but thicker walls, the next brand could be reversed, but the interior volume could be the same or at least a lot closer than just weighing the case would indicate. Heck, different lot of brass with a slightly different alloy could account for a few grains difference in a rifle case annyhow.
  
  I never saw the point of weighing cases due to these possible discrepencies, when it is the interior volume that matters.

  0
• 

  charliemeyer007

  September 07, 2014 17:26

  I always try and buy my rifle brass 200 rounds at a time from the same lot. I usually don't seek a new lot until I'm down to 50.
  
  I fire form the new brass with a good cast bullet load. Then uniform/de-burr the flash holes, trim to length then champher inside and out the case mouth. Use one box for load development, when I get the load the rifle likes I load the rest of the brass. Generally I have only one load per firearm.
  
  I like Norma brass in anything except 44 mag, it didn't the standard shell holder. A real pain in the bucket of range pick up's blasting ammo.

  0

Please sign in to leave a comment.