New Projectiles

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by RockZ, Dec 25, 2008.

  1. RockZ

    RockZ Well-Known Member

    Messages:
    899
    Joined:
    Mar 10, 2006
    Last edited: Dec 25, 2008
  2. JeffVN

    JeffVN Well-Known Member

    Messages:
    620
    Joined:
    Mar 19, 2004
    I know some guys that are shooting some of Noel's .375 banded solid bullets. They require a very fast twist for the caliber.

    I have a gain twist barrel (14" twist gain to a 7" twist - finish at 32") on order from Bartlein for my 338LM Improved (should be delivered in early 2009) and will post results when I get the barrel delivered and test some of the bullets.

    Jeffvn
     

  3. RockZ

    RockZ Well-Known Member

    Messages:
    899
    Joined:
    Mar 10, 2006
    Jeff,
    Great, look forward to the results. I have a 338Lapua Improved also but with a 9.3 twist. It shoots the 300smk's great and I am also going to try the HAT's. It's new so I am not wanting to rebarrel,yet. I have a Stiller Tac 300 to build on and was looking at various bullets to help decide on the next caliber. Looks like their are alot of good 30cal bullets coming out as well.

    Are you going to build a 7mm Holy Grail to shoot those 7mm bullets?
     
    Last edited: Dec 26, 2008
  4. Tyler Kemp

    Tyler Kemp SPONSOR

    Messages:
    1,461
    Joined:
    Aug 10, 2006
    Rock I'm looking to build a 338 Lapua Ackley, any way I could buy a dummy round off you?
     
  5. RockZ

    RockZ Well-Known Member

    Messages:
    899
    Joined:
    Mar 10, 2006
    Tyler,
    I noticed before you mentioned you needed a dummy round, I thought someone was going to send you one.
    I would have sent one out had I known you didn't get it.
    No Problem send me your address, I'll send it out to you next week when I get home.
    I can put a 300SMK in it.
    What length would you like it?
    Don't worry about it, on me. Merry Christmas!
     
    Last edited: Dec 26, 2008
  6. JeffVN

    JeffVN Well-Known Member

    Messages:
    620
    Joined:
    Mar 19, 2004
    Rock

    Yes I'm building a swap barrel rig on my Stiller PreditorX; 338LM Improved for the first, and the second barrel is, in fact, a 7mmHoly Grail. I look forward to throwing some of my Cauterucio 189s at 3,300 fs.

    JeffVN
     
  7. 260shooter

    260shooter Well-Known Member

    Messages:
    271
    Joined:
    Oct 16, 2004
    Jeff

    What is a 7MM Holy Grail?
     
  8. JeffVN

    JeffVN Well-Known Member

    Messages:
    620
    Joined:
    Mar 19, 2004
    338 Norma Magnum necked down to 7mm.

    Jeffvn
     
  9. 260shooter

    260shooter Well-Known Member

    Messages:
    271
    Joined:
    Oct 16, 2004
    Jeff

    Do keep us updated on the 7MM Holy Grail. Very interested. What BC on the 189's?

    260
     
  10. JeffVN

    JeffVN Well-Known Member

    Messages:
    620
    Joined:
    Mar 19, 2004
    according to Bob, .725 at 2,700 fps and over .800 at 3,100 plus.

    I will have some real life comparrison data with the Berger 180 when I get my new 7WSM load tested, as I have Berger 180 data on it now, and will develop a load for the Caut. 189s as soon as I get a chance.

    Jeffvn
     
  11. strictlyRUM

    strictlyRUM Well-Known Member

    Messages:
    225
    Joined:
    Jan 9, 2006
    What is the length on the 189? I am running some #s and want to know what speed/twist to stabilize them. Thanks

    Jason
     
  12. JeffVN

    JeffVN Well-Known Member

    Messages:
    620
    Joined:
    Mar 19, 2004
    Jason

    Here you go:

    Berger 180 - my current lot anyway: Base to Ogive - 0.816" base to tip - 1.533"

    Cauterucio 189 - Base to Ogive - 0.845" base to tip - 1.560"

    JeffVN
     
  13. BryanLitz

    BryanLitz <b>Official LRH Sponsor</b>

    Messages:
    633
    Joined:
    Mar 8, 2007
    I'm gonna go out on a limb and make a prediction, just in the interest of academic curiosity.

    I predict that the BC of the Cat 189's will be about 4% higher than the Berger 180 VLD's. In other words, the average BC from 3000 fps to 1500 fps for the 180 VLD is 0.659. I estimate the average BC of the 189 for the same speed range to be 0.685.

    Of course I stand to be corrected; either way I'm interested to hear about your comparison.

    -Bryan
     
  14. strictlyRUM

    strictlyRUM Well-Known Member

    Messages:
    225
    Joined:
    Jan 9, 2006
    Thank you much Jeff. Well the miller formula says I am good to go.

    Don Miller's Twist Rule
    Caliber 0.284 Inches
    Bullet Weight 189 Grains
    Bullet Length 1.56 Inches
    Barrel Twist 8 Inches/turn
    muzzle velocity 2950 fps
    Temperature 80 degrees Fahrenheit (59 is standard)
    Pressure 29.92 inches of mercury (29.92 is standard)
    Sg =1.93
    Sg shouldn't be less than 1.4. If Sg is greater than about 2.0, you may gain some accuracy by going to a slower twist barrel.






    As far as BC I am guessing closer to .800 if not over. Bergers do not have rebated boattails and or closed tips like the Cauterucios. The last 176s I had I was getting a BC of .740 out of my 7RUM at 3300. Cant wait to get this project under way!

    Jason