Difference between gas check and plain base?

Bill Costik

April 07, 2005 14:42

What exactly is the difference between plain base bullets and gas check bullets? I'm looking at these LBT cast bullets from the Cast Performance Bullet Company. 2 bullets in particular, one is a 275 grain WFNPB, the other is a 300 grain WFNGS. Either bullet will be used in a load for a SBH. Just wondering what the difference is, and whether or not I need a gas check bullet.

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  rimfire72

  April 07, 2005 21:47

  Depends on how "hot" you load them. A gas check is a thin metal(not sure what type metal,maybe someone else knows) base that keeps high pressure loads from deforming the lead bullet base,which will cause accuracy to suffer. Do you have a link for that bullet company,I'd like to check them out.
  
  

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  Bill Costik

  April 08, 2005 02:30

  http://www.castperformance.com/
  
  Theres the link, you can also buy them out of Cabelas, they are a few dollars cheaper per 100 bullets there.

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  Tailgunner1954

  April 08, 2005 02:46

  A gas check is a shallow cup of jacket material, that covers the base of the bullet to prevent "gas cutting" of the bullet base. The lead bullet itself has a slightly smaller base diameter that fit's into the cup (the GC's come with a slight flair, and are crimped in place over the reduced heel on the bullet during the final sizing process).
  Plain Base bullets are totaly flat lead on the bottom, and depend on "opturation" (riviting of the bullet base) to seal the bore.
  The harder the lead (less opturation) or the hotter the load (increased gas erosion of the bullet base) the greater the need for a GC.
  
  

  ---

  Some guys like a mag full of lead, I still prefer one round to the head.

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  richbug

  April 08, 2005 06:31

  Most are copper(hordady,Lyman), I have seen zinc onces once(NBC).
  
  My border collie is smarter than your honor student.

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  Iconoclast

  April 27, 2005 17:12

  Once you start pushing velocities, a gas check is a good thing, regardless of the hardness of your alloy because of the erosive effect of the hot gases on the base of the bullet. The gas checks are generally gilding metal, same as most bullet jackets.
  
  "There is nothing lower than the human race - except the french." (Mark Twain)

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