Sticky bolt lift & brass

Discussion in 'Reloading' started by muleman1953, Apr 12, 2012.

  1. muleman1953

    muleman1953 Well-Known Member

    Messages:
    204
    Joined:
    Oct 17, 2010
    I've been working up loads for a 300RUM, with 225BTHP Match bullets and Retumbo. I started seeing some slight pressure signs at 96gr and the gun shot great at 95.5. Even though I'm not seeing Pressure on my brass it is starting to have the last of the bolt lift hard to pop up & pull the spent case out. I've even had 2 that pulled of the Extractor & I had to push out with a rod. I've checked most everything & I'm thinking now it's Pressure even though the brass Mics out & looks OK.
    Any Thoughts, I could use some Advice, maybe I'm overlooking something.

    Thanks in Advance, Wayne
     
  2. barnesuser28

    barnesuser28 Well-Known Member

    Messages:
    2,808
    Joined:
    Mar 2, 2012
    does your brass have fouling on the outside of the case necks?
     

  3. muleman1953

    muleman1953 Well-Known Member

    Messages:
    204
    Joined:
    Oct 17, 2010
    Yes, What's that mean?
     
  4. Biggs300

    Biggs300 Well-Known Member

    Messages:
    133
    Joined:
    Feb 15, 2011
    Clean the case lube from your brass and you will notice less fouling.
     
  5. barnesuser28

    barnesuser28 Well-Known Member

    Messages:
    2,808
    Joined:
    Mar 2, 2012
  6. Bart B

    Bart B Well-Known Member

    Messages:
    2,483
    Joined:
    Dec 25, 2005
    It is normal when loading that hot of ammo to have the bolt bind a bit when it's opened. Hodgdon data lists 89 grains of Retumbo as a max load with a 220 grain bullet producing 61,000 psi. Plus, if the bolt face is out of square too much, that'll also cause a sticky bolt lift. And if you're just neck sizing the fired cases, that will double the chances of having a sticky bolt lift from insufficient clearance between the chambered fired case and the chamber walls.

    Did you check the fired case heads of any signs of brass extruding into the bolt face cutouts? A bump on the case head where the ejector hole/slot was when it was fired indicates pressure's 75,000 to 80,000 psi.

    I'd back off that powder charge to 89 grains and see what happens.
     
  7. Max Heat

    Max Heat Well-Known Member

    Messages:
    385
    Joined:
    Feb 26, 2012
    Does the brass show a circular "bright" pattern, right around the outside of the primer pockets, but NOT extending all of the way to the edges?

    I've been experiencing that lately (along with & caused by, a tight bolt), so I have NOT been firing the gun. I did try lowering the powder charge by 5 grains, but the result was still the same. So I am thinking that there must be excessive head space. Since I have a new barrel on order, I'm not doing anything until that barrel is ready to go on.