AR primer question

Discussion in 'Ammunition & Reloading' started by noahlanier9, Jun 11, 2013.

  1. noahlanier9

    noahlanier9 New Member

    From what I have read, reloading 223 for a AR a magnum primer is needed to prevent accidental fires when 'sending the bolt home.' in my manual (Lyman's 49th) they use a Remington 7 1/2 primer and from my understanding it is not listed as a magnum. I have read a lot of stuff saying it has a lot of the same qualities and will work. What do you guys think? Thanks for the help, I'm still a newbie trying to figure this reloading stuff out.
  2. Sniper03

    Sniper03 Supporting Member Supporter


    I will not beat around the bush! That is total BS! Standard primers are just fine for reloading 223 or 5.56 casings. So many articals written by these prima donnas of Guns and BS Magazine articles who would like to impress people with their infinite wisdom but are simply full of it! But as I have reflected standard primers are just fine.



  3. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

    I have loaded and shot literally tens of thousands of rounds of .223/5.56 ammo. I have used both standard and magnum small rifle primers. I have NEVER had a slam fire. I would recommend you not use Federal primers as they tend to be the most sensitive available.

    As an extra precaution, always load from the magazine. The resistance of the feed lips will slow the bolt carrier just enough to keep everything fine. If you were to drop one in the chamber and let the bolt slam on it, you MIGHT get a slam fire.

    If I were in a colder climate and using ball type propellant, I would opt for a magnum primer to get the cold, hard to ignite powder going properly. In Texas, it does not get cold enough to cause problems.
  4. c3shooter

    c3shooter Administrator Staff Member

    The difference between a magnum and standard primer is that a magnum has a pinch of powdered aluminum mixed into the lead azide priming compound. On detonation the aluminum is ignited, producing a hotter burn with a smidgin longer flame time (measured in microseconds).

    The hotter flame does a better job of igniting the powder in a quicker manner. It has ZIP to do with slamfires.

    What COULD make a difference is the relative hardness of the metal of the primer shell. And while this can vary to some degree from one maker to another, do not see this as being a real contributor to slamfires.

    Point about loading from the mag is a salient one for ANY magazine fed firearm. To drop a round INTO the chamber and them slam the bolt into battery is making the gun do things it was not designed to do.
  5. gunnut07

    gunnut07 New Member

    I use Wolf Small Rifle Mag primers for all my AR loads. Only because they are the most accurate and they are cheap. Or were cheap.
  6. aandabooks

    aandabooks New Member

    I use Remington 7 1/2 SR Benchrest primers in my .223 reloads and run TAC powder. They re the combo that my reloading guru recommended and so far I've been happy with the results.
  7. mseric

    mseric New Member

    What is needed to prevent Slamfires is to make sure the primer is seated fully and below flush.

    You can use any Small Rilfe primer you wish as long as you seat them properly. All but one that is. The Rem 6 1/2 is designed for low pressure rounds like the 22 Hornet and are not to be used in the 223.

    BTW the Rem 7 1/2 is a Mag primer.