Primer sensitivity

jce12ga

November 22, 2009 21:49

Where can I get info. on primer sensitivity, or more correctly which primers have heavier or thicker cup material?
I have been reloading for several years for shotshell and pistol and some rifle.
The problem I have come across is using some of the Wolf Small Pistol Primers in a .40 S&W Sigma pistol. I have had a few misfires and I am not sure if it is the gun or the primer. Gun is fairly new and the powder I am using has been Hodgdon Universal.
I have used the Wolf Large Pistol primers in two different .45 ACP
chambered pistols with no problems.
I have used several different primer brands over the years in the .45's and could probably count the misfires I have had in 25+ years of reloading on one hand, (well maybe two). I have also used a variety of powders with the .45 ACP loads with no problem.

Any suggestions?

My relaods are conservative and based on info. available in load books andf published data for respective cartridges.

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  perry shooter

  November 23, 2009 01:52

  The PPC group used to lighten their trigger pull but then had Misfires with many brands of primers FEDERAL was the thinnest/ softest cup so EVERYONE used FEDERAL I think the wolf primers ARE your problem not the pistol . You need to practice to become good so buy a box of winchester remington & federal AMMO try all three and if no misfires go with that brand or brands of primers.

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  jonk

  November 23, 2009 03:53

  Every lot has its duds. Sometimes you just get a bad lot. I've fired over 10,000 wolf primers with ONE misfire.
  
  But either way it's a problem in your gun so I'd fire off your remaining primers and when gone, switch brands.

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  Rocky Raab

  November 23, 2009 04:09

  Federals are indeed more sensitive, but it's due to the priming mixture they use as much as the cup. Most cups are almost exactly the same, regardless of maker, contrary to the common belief. They are built to withstand a given amount of pressure, and so a given size/type will be made to the same standards as others in that size/type. Any variation will be very slight.

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  gunnut505

  November 23, 2009 16:30

  quote:Originally posted by Rocky Raab
  Federals are indeed more sensitive, but it's due to the priming mixture they use as much as the cup. Most cups are almost exactly the same, regardless of maker, contrary to the common belief. They are built to withstand a given amount of pressure, and so a given size/type will be made to the same standards as others in that size/type. Any variation will be very slight.
  
  
  +1
  Years ago, G&A Magazine did a breakdown of exactly how thick the metal was in all commercially available primers sold for reloading and came to the conclusion that all were within a few thousandths of each other, with some military primers being thinner than civilian ones.
  The testing they go through in the mfr phase sets the standards; a weighted ball is dropped from a set height and the lots are marked as to which are 100%, 95%, etc. and any lots with less than 100% is trashed (or as common knowledge has it; sold to Wolf[;)]).

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  JustC

  November 23, 2009 17:29

  federal primers are SOFTER, in their external materials, therefore a lighter strike will create enough pressure to ignite the primer.
  
  This is exactly why the LEE hand primer tool says NOT to use federal primers. Even though most of us still use the tool, we know not to "force" a fed primer in the tool, because the pressure exercted by the tool may set off a fed primer if it is cocked or sitting funny upon feeding.
  
  The primer exterior material make-up will cause the differences. CCI etc are hard compared to federal,..I can actually feel the difference when seating federals versus other brands.

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  Rocky Raab

  November 24, 2009 04:11

  Federal cups might be annealed to be softer, but the reason for not using them in a bulk priming tool (Lee or any other) is the priming mix.
  
  There are two types of such mix in use today. They are known as "normal" and "basic", based on their pH value. Federal uses basic and everybody else uses normal. Because of its chemical makeup, the basic type is more sensitive, thus igniting easier. If they are allowed to be in close proximity to others and one ignites, their sensitivity means they are very likely to mass detonate.
  
  This has happened in the Lee Auto-Prime, and in other tray-type and tube-type tools as well. Lee warns users about it, saying not to use Federals at all, and limiting the numbers of other primers (by name) that should be placed in the tool at any one time.

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