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Primers, magnum or not for loading 308?

XTR

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  • Sep 4, 2010
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    Well I searched and didn't find the answer (doesn't mean it's not here).

    What's the general consensus for loading 175 SMKs over Varget (or RL15). Trying to get a bullet that will stay super sonic to 1000 yds so I'm looking for about 2650 MV. Do you use magnum or regular primers?

    Currently I'm using Win 200 regular primers.
     
    Re: Primers, magnum or not for loading 308?

    I use 210M's, I think most people stick with the regular LR primers. with the 210m's and 44.5gr varget, Lapua brass and 175smk I get around 2700 but thats with a 26" tube. That extra barrel length makes a difference IMO. Out of my 20" 308's i really struggle to just get to 2600, I think with a 24" or longer is way easier.

    CJG
     
    Re: Primers, magnum or not for loading 308?

    I usually drop mag primers in 308 sub loads, but as was said, the standards seem to do just fine.

    maybe go mag if you were to shoot in extreme cold?
     
    Re: Primers, magnum or not for loading 308?

    Mag primers have thicker cups and SOMETIMES more bang (not always). Also, primer strength will vary from manufacturer to manufacturer. Wins are stronger, CCI's and Federals are more mild.

    If you google around a bit you can find various articles and tests where they used high-speed cameras to photograph the primer flash of various brands.
     
    Re: Primers, magnum or not for loading 308?

    With extruded powders (typically single-base), especially with the small capacity of the .308Win, a Standard Primer is entirely adequate and thought to improve accuracy. However, cases with greater than 80grs capacity can benefit from Magnum Primers.

    Some ball powders (typically double-base), Magnum Primers can be recommended, especially in cold weather conditions.

    As previously stated, Magnum Primers typically have thicker cups and are SUPPOSE to have greater brisance. Some do and some don't.

    I did some informal testing and my loads did not shoot any less or more accurately with Standard or Magnum (+15fps). As a result, I standardized on Magnum Primers across the board to simplify my life. Why Magnum instead of Standard?; My reasoning is better to have it and not need it than need it and not have it.....YMMV
     
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    Re: Primers, magnum or not for loading 308?

    Standard primers for .308

    Note: Wolf Russian Primer Magnum Primers have hard brass cup while the standard primers have a soft copper cup not more primer mixture.
     
    Re: Primers, magnum or not for loading 308?

    I am with Buffybuster...I shoot Magnum primers exclusively in my .308 long range loads with Varget. I recall an article in one of the shooting magazines about 2 years ago...where the Magnum primers shot the most accurate in a SAKO TRG-22. They fired a LOT of different loads, but the mag primer reloads were the tightest groups..even beating out the Match primers!

    I use CCI 250 Large Rifle Magnums, as they are the easiest for me to purchase.
     
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