Just When You Think You Have Seen It All

Discussion in 'Reloading' started by Colorado Cowboy, Jun 28, 2011.

  1. Colorado Cowboy

    Colorado Cowboy Well-Known Member

    Apr 23, 2011
    I've been reloading for over 50 years...all types of metalics and shotgun. I built rifles and reloaded for 22-250 and 25-05 BEFORE they were factory calibers. Just telling everyone this so you know I've been doing this awhile.

    I have a commercial Mauser actioned .300 Wby that was given to me. It was imported by Stoeger in the 60's. Nice gun, but wouldn't shoot well at all. Would not group, no pattern to shots, just all over the map. Looked at the barrel and it was shot, lots of throat erosion. No telling how many rounds had been thru this baby. I had worked out a load that would shoot the best, but not good at all (at least for me!), best I could do was about 5 minute groups, yuk!!

    Put on a new Shilen match SS barrel and started breaking it in. With the other baseline load and some factory I had, the best I could do was about the same as the old barrel (huh!). Started from scratch. Inspected all cases, checked for OAL case length, full length sized and reprimed them. All cases are Weatherby. I like Nosler Partition for elk, but decided to load up some Sierra spitzer BTs too. I really like Reloader 25 for the big cap cases and this is my powder of choice. Loaded up 3 ea of each powder charge with 1/2 grain increases from the lightest load. Did the same for the Nosler and Sierra bullets.

    Went to the range yesterday and did a little work. None of the Sierras shot well at all. I got to the last 2 Nosler loads and got one group that all 3 holes were touching (at 100 yds). I now felt a little better.

    The load that shoots the best.....a 1/2 grain LESS than what I had tried initially (my old baseline load). Go figure.....never in all my years reloading did a half grain of powder make THAT much difference. Now I'm loading up a few to take to the 500 yard range to seal the deal (I hope).
  2. Grumulkin

    Grumulkin Well-Known Member

    Dec 22, 2010
    I've seen 0.5 grains of powder being the the difference between 1 MOA groups and way less than 0.5 MOA groups. Different powder have longer or shorter, shall I say, flat spots in the pressure/powder charge curve where where adding a little powder makes a little or a lot of pressure difference.

    In a 300 Win. Mag., I've found H4831SC has a pretty narrow optimal load range while in a 7mm Rem. Mag., RL-22 has a pretty wide range of powder charges where accuracy is about the same. I guess the problem come in when you assume that checking powder charges in 1 grain increments makes you miss the sweet spot or when a powder with a narrow good accuracy range is temperature sensitive.
  3. Tikkamike

    Tikkamike Well-Known Member

    Dec 26, 2009
    WOW I have never seen that either, that is pretty extreme
  4. LRSickle

    LRSickle Well-Known Member

    Jun 8, 2009
    Wow, that is extreme. With that narrow of a sweet spot it would have been easy to miss it and try loads under and above it. I'm wondering if, with such a narrow sweet spot, how much temperture change will effect your groups. I'm not familiar with that powder but with RL22 high temps will cause my groups in my .257 Wby to open up at 70 degs and up. Just a thought.