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Thread: Primer question - Large Rifle vs. Magnum Large Rifle

  1. #1
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    Default Primer question - Large Rifle vs. Magnum Large Rifle

    Does anyone know if a magnum large rifle primer can be used in place of a regular large rifle primer ?

    And if so, does one need to adjust the powder charge any? I've read that with small rifle primers
    there is no difference in charge from a regular primers to the magnum primers, just the cup is
    thicker to handle the higher pressure so you don't get blown primers with higher pressure loads.

    The reason I'm asking this is I'm about to run out of Alcan regular large rifle primers and have
    a large amount of Alcan magnum large rifle primers to use. The rifle and load I'm using these in
    is for my K-31 Swiss, current load is 41 grains of 4064. So I'd like to use these primers but am wondering if I need to decrease the powder charge if there is a bigger bang with magnum primers.

    Thanks for the input

  2. #2
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    To use a mag primer in place of a standard and keep it about the same reduce the load by 1/2 grain powder. A rule of thumb and not exact, your mileage may vary. HTH
    Ineptocracy (in-ep-toc'-Ra-cy) - a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers.

  3. #3
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    The difference between a standard primer and a magnum primer is the compound in them. A magnum primer has more brissance which is more fine particles of aluminum in the compound that when fired drives deeper into the case load of powder breaking apart more powder granules and starting the powder burning further into the case which insures large loads of slow buring powder will ignite better and quicker. As Bud said reduce your powder charge and work up from there. The primer cups are the same with standard and magnum primers. The difference is in the compound used.

  4. #4

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    I found the primer cups of Remington small rifle # 7½ magnum to be more resistant to flow than the standard #6½ primers. The #6½ gave me fits in a falling block Martini in 22 Hornet. The #7½ took care of the flow, but did not provide good accuracy in the small case.

    I ended up trading for a bolt action in 222 and never looked back!

  5. #5
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    Quote Originally Posted by Ken in Iowa View Post
    I found the primer cups of Remington small rifle # 7½ magnum to be more resistant to flow than the standard #6½ primers. The #6½ gave me fits in a falling block Martini in 22 Hornet. The #7½ took care of the flow, but did not provide good accuracy in the small case.

    I ended up trading for a bolt action in 222 and never looked back!
    The 7 1/2 Rem. has a thicker case than the 6 1/2 and in my opinion, the 7 1/2 should be used for all small rifle applications. I had nothing but issue's with the 6 1/2's in 222 Rem, leaking primers, primer flow and firing pin punctures. After damaging a bolt, I learned quickly and switched to the 7 1/2's. The bolt back in 1963 cost me $45.00 to have sleeved.
    Matt
    "When you tax away the rewards of effort, you destroy the motivation to achieve"

  6. #6
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    Another factor is the composition of the powder. Some powders require a magnum primer to sucessfully light off the powder. I tried some surplus 4895 that specified a mag primer. I tried a LR rifle primer to see if if the recomendation was true or not. It was true. I only loaded three rounds to test.

  7. #7
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    You are correct on the powder issue. I always look to see what primer was used during their testing in the particular reloading data I am using. Although, I only load 222, 223 Remington and 22 CHeetah using converted 30BR cases that use a small rifle primer. Everything that I load requires the magnum primers!
    If you are shooting any cartridge that requires a small rifle primer, anything over 36,000 CUP requires a BR or Magnum style primers. The 6 1/2 just doesn't have the capacity to handle the pressure.
    Matt
    "When you tax away the rewards of effort, you destroy the motivation to achieve"

  8. #8
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    Truth is you must do your homework with primer changes. Wolf or Tula primers (any Russian primer made by Murom Device) has zero difference in output, the magnums merely have a thicker cup. CCI #34 are considered to be magnum output which makes sense as they are mil spec and must operate reliably at -40 F. Some "normal" strength primers have comparitively high output while some match primers have a very "soft" output. Its your eye behind that reciever, I always drop to minimum charge and redo the testing when switching components. See links below for some interesting photos on primer output. BTW the Remington 6 1/2 is designed to be soft and Remington's website use to tell you to only use that primer for (if I remember correctly) the 22 Hornet. It has been sometime so I might not have the right chamber there.

    http://riflemansjournal.blogspot.com...mer-study.html
    http://riflemansjournal.blogspot.com...mer-study.html

  9. #9
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    Quote Originally Posted by Matt Anthony View Post
    The 7 1/2 Rem. has a thicker case than the 6 1/2 and in my opinion, the 7 1/2 should be used for all small rifle applications. I had nothing but issue's with the 6 1/2's in 222 Rem, leaking primers, primer flow and firing pin punctures. After damaging a bolt, I learned quickly and switched to the 7 1/2's. The bolt back in 1963 cost me $45.00 to have sleeved.
    Matt
    You used Rem 6-1/2 primers in .222 reloading and damaged the bolt back in 1963??
    Last edited by Hefights; 06-29-2012 at 07:09.

  10. #10
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    Here we go, found it on the Natchez website:

    "Warning: Remington does not recommend this primer for use in the 17 Remington, 222 Remington, 223 Remington, 204 Ruger, 17 Remington Fireball. Use the 7-1/2 Small Rifle Bench Rest primer in these cartridges.

    # This 6-1/2 Small Rifle primer is primarily designed for use in the 22 Hornet."

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