Useing one brand of primers can cause slam fires in free floating fire pins?

Discussion in 'Ammunition & Reloading' started by Nickwashere, May 16, 2012.

  1. Nickwashere

    Nickwashere New Member

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    Ok, I am new to reloading and I know that there are two sizes of primers (large and small) and two primer set ups..(rifle and pistol) along with two strengths (regular and magnum)

    So I know that rifle primers have thicker cups which take more force to ignite.. I just seen a you tube video that freaked me out.. It said that some primer brands for rifles are designed for bolt action and do no have a thick enough wall for semi autos with free floating fire pins causing slam fires... (such as a AR15).. Is this true? It has freaked me out out.. I thought all rifle primers in proper size were safe to use on my semi auto weapon..
     
  2. Nickwashere

    Nickwashere New Member

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    [ame]http://m.youtube.com/watch?v=4gMbu-yvwfw[/ame]
     

  3. The_Kid

    The_Kid New Member

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    A slam fire is when the bolt slams into the chamber then the firing pin continues and hits the primer firing the round. It is a dangerous situation because some people might not have the firearm pointed in a safe direction when cambering a round. Slamfires don't destroy the firearm.

    Now an out of battery ignition has the potential to do damage, which isn't the same thing.

    It could be possible for a case to be not have ejected remaining in the action, whereas it could cause a slam fire out of battery... so yes it is possible, just as I would think improbable.

    This guy does a few slam fires on purpose.
    [ame="http://www.youtube.com/watch?v=xj3QtnUWCwQ"]http://www.youtube.com/watch?v=xj3QtnUWCwQ[/ame]
    It doesn't destroy your firearm, but it is dangerous..
     
    Last edited: May 16, 2012
  4. Dan308

    Dan308 New Member

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    so this guy is telling me that there are BILLIONS of rounds of .223 out there that will slamfire? Not sure I believe that one. Sounds like a gun problem more than a ammo problem.

    Why would you use a "match" primer to spray targets?
    why would you need a Mag primer in a .308??
    He didn't test any military rounds to see if they too had dented primers.
     
    Last edited: May 16, 2012
  5. res45

    res45 New Member

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    James videos pretty much covers the basics of free floating firing pins,soft primers and slam fires. I've personally had one in my SKS rifle but it was intentional as I was testing different batches of primers for that very purpose the rds. were not loaded just primed.

    A couple of things to note is that just because you use a specific primer designed for rifles with free floating firing pins doesn't necessarily mean you want have a slam fire using them,dropping the bolt on a chambered rd. not seating the primer fully into the primer pocket or a mechanical malfunction of the safety features built into some rifles can still cause a slam fire.

    James has another video on primers and seating [ame]http://www.youtube.com/watch?v=AiPu36-M9LM&feature=plcp[/ame]

    My friend Frisco Pete has an excellent articles entitled A Primer on Primers. It goes into a lot of detail on all the various aspects of primers and there different applications http://www.sksboards.com/smf/index.php?topic=56422.0

    The great majority of Mil-Spec primers are not match grade primers. They either have a thicker or harder cup material which makes them less sensitive to the firing pin strike.

    Well that depends most Mil-Spec primer are in the magnum range of primer brisance to begin with the CCI #34 and 41's certainly are and although the Win. LR isn't designated as a Mag. primer it's one of the hottest primer there are. You also have to take into account that in some reloading manuals magnum primer are denoted because of the type powders used ie ball powders,some ball powder ignite readily with a standard primer while other require a magnum primer especially in colder weather. All standard primer are not the same as far as there brisance and neither are magnum primer.
    Not on that video he was just covering the basics,but I have tested various military rds. and they dimple to one degree or another but not the same as when using soft cup commercial primer.

    Here is a bolt drop test I did in my SKS rifle using several different type primers all seated to the exact same depth. As you can see I dont use the CCI BR primer in that rifle.
    [​IMG]
     
    Last edited: May 16, 2012
  6. Nickwashere

    Nickwashere New Member

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    So if I am using a rifle rated primer and I am loading it correctly (not protruding and flat with correct depth) then I am doing the necessary steps to avoid slam fire (while its still possible that a slam fire could occur,i am not creating any unnecessary safety issues).. Buying one rifle brand over another doesn't significantly increase or decrease chances of slam fire..from your personal experiance..right?
     
    Last edited: May 16, 2012
  7. Nickwashere

    Nickwashere New Member

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    By the way, the you tube video on primer pocket depth was very helpfull!
     
  8. res45

    res45 New Member

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    That would be correct if the primer your using is one of those considered suitable for use in semi-auto rifle with free floating firing pins.

    Well that depends on if your talking about the AR style rifle,since I don't reload for one I can't say one way or another if all the various version of the AR's firing pin systems are standard or not,I would think they are but there is always an exception.

    As far as my 7.62 semi-auto I can tell you that they are not all standard some dimple the primers more some less but none give me any issues as long as I use a suitable primer and seat it correctly for those type systems. Finding a suitable primer is not really that big of an issue all the major brands make a primer suitable for semi-auto rifles with free floating firing pins.
     
  9. Nickwashere

    Nickwashere New Member

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    thank for the advice being new to reloading- I find it very helpful haveing access to knowledge from experienced reloaders such as yourself :)
     
  10. Dan308

    Dan308 New Member

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    I guess my point was don't use a match primer when all you're going to do is shoot a few paint cans.

    point 2, for a semi auto you shouldn't need a mag primer for the powder. I'm pretty sure a Fed-210 would set off BLc-2 anywhere in North America.


    But really I get the vid and what it implies, I've never noticed a problem when shooting commercial or reloads in my M-1
     
  11. steve4102

    steve4102 New Member

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    You can include the Rem 6 1/2 SRP and the Rem 1 1/2 SPP to your list. They are designed for Low pressure rounds and are not to be used in High pressure rounds like the 223/5.56 and the 40 S&W.
     
  12. res45

    res45 New Member

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    I would agree but sometimes you have to use what you have on hand. Match primer depending on your location are generally more expensive,there about $3 more per K from my vendor. Also Match primer are suppose to be more consistent from primer to primer and are usually made at the factory by the more experienced workers. However that is not always the case as described in this study done by the DOD. It's basically covers Lead Free Primers but read point #4
    I've actually found through my own chrono testing that the Wolf LR and SP primer I use give lower SD's than my American commercial primers with same load.

    http://bulletin.accurateshooter.com...ts-in-dept-of-defense-lead-free-primer-tests/

    Maybe or Maybe not depends on load density and temperature Fed-210's are in the Med. heat range as primer go there also not recommended for using in semi-auto rifles.

    M1 Owners Manual
    [​IMG]
     
  13. BlueTurf

    BlueTurf New Member

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    I experienced slam fires one time. I was at the range with my SA M1A. I don't know if it was the primers that caused the slam fires but I was shooting two and three-round bursts. The people around me thought I had a full-auto rifle and were checking me out real good. I assured them my rifle as semi-auto only. I started with a very clean rifle and thoroughly cleaned and inspected it afterwards. I never experienced this problem again. At the time I was shooting some loads with CCI large rifle primers. I was using the primer tool on my Rock Chucker press at the time, which doesn't work very well. Since then I bought a Lee priming tool that works so much better.
     
  14. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    Federal primers have a reputation for being "soft". Remingtons are little harder and Winchester harder still. In pistols, CCI primers are very hard. Not sure about rifles.

    The SKS is the most prone to a slam fire. I use Winchester or CCI primers and have no issues. I also removed the firing pin on both my SKS's and deburred/polished the sides. I am not so worried about the floating firing pin setting one off by inertia as I am about a stuck firing pin setting a round off prematurely.

    Ball propellents generally ignite with standard primers in cold weather. The problem is actually with the rate at which the powder burns. Cold weather and weak primers will lead to inconsistent ignition and accuracy problems. In extreme situations, squib loads can result from insufficient primer "oomph".