close
Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Reloading

Reloading Berger Bullets

Reply

300 RUM load development questions

LinkBack Thread Tools Display Modes
  #134  
Unread 03-26-2013, 01:32 PM
Platinum Member
 
Join Date: May 2008
Location: South of Canada and North of Wyoming
Posts: 6,068
Re: 300 RUM load development questions

Pics would be good
__________________
- Mark

You will never know how much it has cost my generation to preserve your freedom. I hope you make good use of it.
~ John Quincy Adams
Reply With Quote
  •   #135  
    Unread 03-26-2013, 02:08 PM
    Bronze Member
     
    Join Date: May 2012
    Location: Northern Colorado
    Posts: 92
    Re: 300 RUM load development questions

    300 RUM load development questions-img_20130326_123739_137.jpg

    This shows that not all primers are cratered, and maybe they dont appear to be too flattened. The ones on the left have no cratering, but the ones on the right do. These were all fired yesterday from 90 - 92 gr. These primers have a very different look, I'm not sure why. I'm extra careful on my charge weight's, and check each one with a check weight set before and after I've charged each 3 round weight group.

    300 RUM load development questions-img_20130326_124413_598.jpg

    In this view the case heads look good, I think.
    Maybe I should ignore the primer cratering. The 3 case heads are from the 92 gr loads. The warmest. I'm not convinced that I'm seeing pressure signs, but the velocity increases that I expected weren't there.

    Between 88 & 90 gr the velocities seem to be readable, but from 90 - 92, I cant read much of anything into the velocities. At 92 gr the velocities straighten back out, but not what I had expected.
    So with 210 VLD's if I remember correctly without going back and looking. This thread has gotten a bit long. Were you running 92 gr?, if so what kind of velocities were you getting?

    Last edited by cerwin; 03-26-2013 at 02:45 PM.
    Reply With Quote

      #136  
    Unread 03-26-2013, 03:35 PM
    Platinum Member
     
    Join Date: May 2008
    Location: South of Canada and North of Wyoming
    Posts: 6,068
    Re: 300 RUM load development questions

    Those primers do not look flattened. They still have well rounded edges and the cratering is inconsistent. It looks like a firing pin issue to me. You might want to consider a new assembly or at least a new spring and have it checked by a smith.

    PTG Remington 700 Traditional Non-ISS Firing Pin Assembly Long Action

    My new RUM build is getting a whole new PTG bolt and trigger assembly.

    I did say 92 gr from memory but went back and checked my notes. The actual charge was 93 gr with an approx average velocity of 3130.

    What were the light conditions when you were chronying these loads? Any clouds or shadows? Late afternoon - early evening? I have seen velocities flatten out when pressures get high and I have also seen them spike.
    __________________
    - Mark

    You will never know how much it has cost my generation to preserve your freedom. I hope you make good use of it.
    ~ John Quincy Adams
    Reply With Quote
      #137  
    Unread 03-26-2013, 03:52 PM
    Platinum Member
     
    Join Date: May 2008
    Location: South of Canada and North of Wyoming
    Posts: 6,068
    Re: 300 RUM load development questions

    These are flattened primers. This was a max load in my 7 RM. Notice the 2 factory cases with gold colored primers in the lower left
    Attached Thumbnails - Click to View Larger
    300 RUM load development questions-img_0429.jpg  
    __________________
    - Mark

    You will never know how much it has cost my generation to preserve your freedom. I hope you make good use of it.
    ~ John Quincy Adams
    Reply With Quote
      #138  
    Unread 03-26-2013, 04:39 PM
    Bronze Member
     
    Join Date: May 2012
    Location: Northern Colorado
    Posts: 92
    Re: 300 RUM load development questions

    ;
    Quote:
    Originally Posted by MontanaRifleman View Post
    These are flattened primers. This was a max load in my 7 RM. Notice the 2 factory cases with gold colored primers in the lower left
    I have a new PTG bolt body, but the firing pin assembly is the original from factory. I will replace with a PTG firing pin assembly.
    The light conditions were sunny, early morning. About 15 degree temp. I kept my ammo in my truck to about a 45 degree temp. About the same temp as the last round of testing.
    I'm thinking that amount of flattening should not be a problem. Would you think I've reached max at 92? That max shot nearly as well as the 88 gr I started at.
    At 92 gr. I chrono'd a 3090 fps avg.
    Reply With Quote
      #139  
    Unread 03-26-2013, 05:08 PM
    Platinum Member
     
    Join Date: May 2008
    Location: South of Canada and North of Wyoming
    Posts: 6,068
    Re: 300 RUM load development questions

    Your 92 gr velocity is in line with my 93 gr velocity. I think you'll be OK climbing another couple of half grain steps.

    Or, you might consider starting @ 89 gr to the lands and climbing to see if you can tighten up the groups a little.
    __________________
    - Mark

    You will never know how much it has cost my generation to preserve your freedom. I hope you make good use of it.
    ~ John Quincy Adams
    Reply With Quote
    Reply

    Bookmarks

    Thread Tools
    Display Modes



    All times are GMT -5. The time now is 03:44 PM.


    Powered by vBulletin ©2000 - 2017, Jelsoft Enterprises Ltd.
    Content Management Powered by vBadvanced CMPS
    All content ©2010-2015 Long Range Hunting, LLC