Powder for Necked Up 6.5 PRC

Rockdoc173

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Minuteman
  • Aug 26, 2014
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    I necked up a 6.5 PRC to 7mm in a SA Archimedes with a 28" barrel. My first test loads used 52.5 to 57.0 of N-165 in .5gr intervals producing this graph.
    1670676039628.png

    I loaded up 10 more using old 168 VLDs I had going from 55.0 to 59.5 of N-165. I haven't fired those yet but I don't think I'm going to make the last few due to pressure, they're pretty compressed. So, here's the question: I need more speed out of the 166 ATips with less case volume so, do I go faster powder? If so, how much faster? I have some 4831SC that I'm going to try out, or should I look at going into the N-550 to RL-17 range? I guess I'm not understanding sufficiently the relationship between case volume, burn rate, and velocity
     
    I think h4831sc would be perfect in that setup. I run it in 6.5prc and it is a little fast burning for a long barrel and heavy bullets. Bumping up to 7mm should put h4831sc perfectly in the range.

    The 7-6.5prc is popular with f-class shooters. You might search around on those forums too.

    I went back and re-read your post. If you are truly just looking for more velocity, you might be at the limit of the cartridge. Sometimes you can only squeeze so much juice from a lemon. The easiest way to get big gains in velocity is bullet weight........better bullets (lighter weight and higher BC).

    Ern
     
    Last edited:
    The whole reason I did this build was to tickle a steel target at 2k and have more energy than a 6.5 PRC. Quick math keeps a 153 ATip >M1 all the way out to 1700. With the 166/168s I'm not getting close to that. I need the velocity because I need the BC. If I can't make that happen, I'll just switch to a 6.5 PRC barrel and move on. I'll check the FC forums for it though. Thanks
     
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    Reactions: Jackomason
    I got ya. I like your style Dude.

    Thats a cool project idea, let us know how it turns out......I think you are on the edge of working and not working.

    Btw - H4831sc has been great for me accuracywise......but if you need the velocity too it may be a waste of time, it always seems to be midrange on velocity.

    Ern
     
    I necked up a 6.5 PRC to 7mm in a SA Archimedes with a 28" barrel. My first test loads used 52.5 to 57.0 of N-165 in .5gr intervals producing this graph.
    View attachment 8017924
    I loaded up 10 more using old 168 VLDs I had going from 55.0 to 59.5 of N-165. I haven't fired those yet but I don't think I'm going to make the last few due to pressure, they're pretty compressed. So, here's the question: I need more speed out of the 166 ATips with less case volume so, do I go faster powder? If so, how much faster? I have some 4831SC that I'm going to try out, or should I look at going into the N-550 to RL-17 range? I guess I'm not understanding sufficiently the relationship between case volume, burn rate, and velocity
    How did you neck it up? Stepped mandrels or strait to .284?
     
    I'm tagging in for this. I have another thread going but I ordered a barrel last week.

    I've got
    H1000
    H4831
    N555
    H4350
    IMR 4350

    So far I've been able to fit 60gr of h1000 under a 180 hybrid @ 2.955" oal. This was just to see how much would fit and not an actual load.

    166 Atips may be the ticket in a short action. But there doesn't seem to be many reports on them.
     
    • Wow
    Reactions: HOOFER
    Just put 58.7gr in and all fit well. It was compressed but couldn't hear it crunch.

    This is what F-class john is running at 2925fps. Not sure what that means for me at a much shorter OAL but the powder fit!