Pressure Question...Agree with this?

Discussion in 'Reloading' started by cohunter14, Nov 25, 2012.

  1. cohunter14

    cohunter14 Well-Known Member

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    I am just getting in to reloading for my 300 RUM and was curious if you experienced reloaders agree with this small article: Primers (Pressure Signs)

    My primers look like #2 on this list with just a minimal amount of flattening, which I thought might be a sign of too much pressure. However, based on this write-up, I can actually increase my load. I just want to make sure I have this correct before moving forward. Thanks for any information!
     
  2. Mikecr

    Mikecr Well-Known Member

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    Of pressure signs, primer appearance is pretty much the least meaningful.
    What is meaningful to any reloader is whether brass extracts from the chamber with a 'problem', or not. Typically, with rational load workup, a problem is preceded by several validating 'signs'.
    Lookup pressure signs.

    Your reloading reference is also validating to what you see. But there are often local factors(like your sizing, barrel, temps, lot of powder/primer, bullet seating, etc) that affect the REAL outcome.
    With this, again, the only real problem is just that. And if it's not a problem then it's also just that.

    I don't care about flattening primers. In themselves, they don't hurt a thing. They don't mean my pressure is 4Kpsi over somebody's book max(and who cares). They don't directly mean my primer pockets will loosen(a problem). They are one sign.
    Now if I'm 2.5gr over several reference source's max, my chrono validates this, my primers are flattening, I have a webring forming, and extraction is getting difficult? It's time to predict a problem in brass life atleast, and how will I manage this?
    Well, if my load is performing real damn good, I might live with tossing cases after a few firings. That's one solution many point blank BR shooters adopt(not me).
    Otherwise, I'll back off & seek a better load(better for me).

    A reloading problem, like accuracy, is locally defined by the reloader. Just use common sense and caution. Stay engaged with it.
     

  3. cohunter14

    cohunter14 Well-Known Member

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    Thanks for the info Mikecr! I have not had any other real pressure signs on the case or in the extraction, so I just wanted to be sure that I had the primer-flattening idea correct. Based on the link I posted, I should easily be able to work up on that load, but I just wanted to be sure.
     
  4. BountyHunter

    BountyHunter Writers Guild

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    Due to primers having different cup hardness, it is hard to establish overall pressure by that alone. It is often misleading.

    Ejectors marks and extracton are more reliable.

    Actual pressure testing of primers has shown that you can have a 5000 PSI difference with just a primer change.

    That is another reason, if you change one component, start testing over.

    BH