6.5CM Changing brass from Norma to Prime & Laupa - charge info needed

Crang

What me worry?
Full Member
Minuteman
  • Apr 13, 2006
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    Texas Hills
    I have a great load worked out for my Tikka 6.5CM using Norma brass with a 42.2gr charge of H4350. The brass is nearing the end of its life. I am going to switch to Lapua brass but also have a pile of Prime headstamped Norma brass. So 2 questions:

    Is the Prime brass identical in every way (case capacity mostly) except headstamp so I can just use the same charge and not even worry about it?

    How much of a charge reduction are you seeing to get the same velocity in the Lapua brass? Looking for info to the .1 of a grain from someone who has made the switch, not a general 'about a half a grain'.

    My time got super limited lately with a new job and an extra range trip to get it worked out and fine tuned will set me back more weeks than I have. I'll be really grateful if someone an save me a couple weeks to figure it out. Thanks so much-
     
    The only answer I have is about charge weight differences. Drop your Norma charge and work up slowly using your Lapua brass until you reach the same velocity. Load up 2 to 3 rounds in .2g increments and chrony them all. You'll find the velocity fairly quick and easy.
     
    The only answer I have is about charge weight differences. Drop your Norma charge and work up slowly using your Lapua brass until you reach the same velocity. Load up 2 to 3 rounds in .2g increments and chrony them all. You'll find the velocity fairly quick and easy.

    Thanks. Thats what I would normally do. Just pressed for timing and looking for a shortcut if someone has it figured out already!
     
    As you said, Prime is Norma brass and I like its performance so far in my .260. I have about nine loadings so far on my Prime .260 brass and pockets are still good. I anneal them about every 2-3 firings, which seems to work pretty well.
     
    As you said, Prime is Norma brass and I like its performance so far in my .260. I have about nine loadings so far on my Prime .260 brass and pockets are still good. I anneal them about every 2-3 firings, which seems to work pretty well.

    I'm on my 4th loading of the Norma and a few of the pockets are feeling a bit looser but still have a ways to go. I run them a tad on the hot side. I did recut the primer pockets and take a deburr tool to the flash holes. Noticeably more shavings than the Lapua but in my accuracy node I have been getting ESs as low as 5fps on 5 shot groups. Would like to have loads worked out for both Norma and Lapua as I stock both size primers and just buy whatever is cheapest on any given day.