375/408 Banded Solids Test

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Augustus, Mar 1, 2009.

  1. Augustus

    Augustus Well-Known Member

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    As stated in another thread I have recieved my rifle from Lawtons. It is a 30 in 8 twist on an 8000 action in a Manners stock bedded by Lawton. Noel Carlson presented me with samples of prototypes of his banded solid 375 bullets. He sent me samples of two different configurations. The first is a copper 431 gr. and the other is a brass 417 gr of identical demensions. The copper by far is the most interesting of the two. I started out with 130 gr of US869. The holes were round and there was no excessive pressure. I continued to step it up and attained 2965 fps with 150 gr of US 869. At this point the bolt became a little sticky and there were slight ejector marks on the case. The cases from Jamison are first class, I only used 3 cases for the tests and have 32 loadings on each case. There have been no split necks and the pockets are still good. I encountered stability issues at the higher velocities and Noel is tweaking the design to correct this. At lower velocities accuracy is very good, 100 yd 3 shot groups were .3 to .4 moa. The most outstanding display of accuracy was a 1/4 min. three shot group at 600 yds. At 1020 yds a half min. was attained. I was having more ES than desired on velocity at the lower velocity end of the spectrum which caused vertical stringing at distance. This was caused by the 125 gr of BMG which left a huge amount of the case unfilled. The load that produced 2900 fps was 145.5 gr of US 869. This load produced ES in the single digits and showed no signs of excessive pressure. This bullet could probably be driven very close to 3100 fps from the 408 improved versions. Think of this, you have a 431 gr projectile traveling at 3100 fps with a BC ------ OK here goes----- around 1.2 +. Fowling is a non- issue. Cleaning this rifle takes less effort than any of my custom 308 barrels. I fired into a couple of different medians and the nose bends past 90 degrees. I shot one into a clay bank, when it was recovered it was a round circle with the center touching. Anyway we are on the verge of seeing something awesome, if Noel can make the tweaked version fly as well at 2900-3100 as the first ones did at slower velocities, long range shooting just got a boost.
     
  2. davewilson

    davewilson Well-Known Member

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    very interesting, thanks for the report. can you describe in a little more detail what you mean by the bullet was a round circle with the center touching.( i'm sure nobody will notice the 1.2 B.C.)
     

  3. Augustus

    Augustus Well-Known Member

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    Upon striking a median these bullets have a very predictable habit of the first 1/2 inch of the long thin nose folding to one side. It dont seem to take a lot of impact for the nose to bend ninety degrees to the body. When I fired it into the clay the nose completely folded back and the body also bent causing the recovered projectile to look like a doughnut with a little tiny whole in the center. Right now I cant tell you how fast this will happen when striking a game animal; however it dont seem to take much to get at least the first 1/2 inch of the nose to go ninety degrees. These bullets are copper and after they have been perfected there may be a oxygen free copper version that will deform more quickly. Just as it is I think on Mule deer and Elk this thing would be devastating. The hunting applications of this projectile is still a big question mark. We will see. I dont know if it would be legal in some states.
     
  4. JeffVN

    JeffVN Well-Known Member

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    Thanks for the update. It sounds like Noel is getting these bullets done right.

    JeffVN
     
  5. Augustus

    Augustus Well-Known Member

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    The 338 bullets fired from a 408 improved case traveling at 3300 - 3400 should really fold up. The cases are very good now and if an SMK can be driven to these velocities the banded solid can be driven faster. I would not be surprised to see reports of 3500+. I have not fired a 338/408 using any projectile but i am hearing some of the Improved versions are pushing the 300 SMK the 3300-3400. Run the numbers of a 1+ BC bullet driven at 3500. OUCH!!!
     
  6. davewilson

    davewilson Well-Known Member

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    does he offer any of the 338 bullets and can we look at these any where?
     
  7. Augustus

    Augustus Well-Known Member

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    I have a few of the 7 cal 338 bullets, as far as I know there are no rifles built to fire them yet. You can pm Noel and he will probably send you a sample or post pics. I have a 9 twist on the way and I will try them out of it. I dont expect them to stabilize in anything less than a 7 twist.
     
  8. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Sounds very interesting and very impressive performance for sure.

    What do they cost?

    Unfortunately, here in Montana, they would not be legal for big game hunting as they are not an expanding bullet.
     
  9. Augustus

    Augustus Well-Known Member

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    Fiftydriver, I think that is a question for Noel Carlson, I have a pretty good idea but I think Noel will come on and share that after these things have flown a little more and are proven. As you know one can pay a very heavy price for prematurely offering a product for sale. As stated in an earlier post I did experience instability at higher velocities, Noel is sending me the tweaked ones next week and I will post the results. Noel wants these tests to be transparent. He is confident the kinks will be worked out PDQ.
     
  10. davewilson

    davewilson Well-Known Member

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    i have a friend that has a 338/378 with an 8 twist 40" barrel. i know he was going to try some of the Lehigh's. he'd probably test some. i assume you mean the 338 is 7 calibers long?
     
  11. noel carlson

    noel carlson Well-Known Member

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    Kirby, Dave,

    These Von Karman projectiles are seven calibers in length, and are designed to function optimally from an exponential gain-twist barrel with an exit rate of ~20 calibers. In the case of Terry's .375, this would translate to a 1: 7.5" twist, which is slightly tighter than the 1: 8" constant-twist Lawton employed with a degree of success recently.

    The .338 would require a still tighter rate of 1: 6.75".

    A recent fall in copper prices has helped my pricing structure. The projectiles will be more than competitive with comparable solids, but I want to make the necessary refinements prior to formal marketing.

    2,800fps-plus barrel exit perturbations/blast instability needs to be resolved in the, otherwise, dynamically stable flight properties of this design. There is also need to ensure that the engraving bands are stout enough to be interchangable with a constant-twist rifling geometry.

    It should be noted that this is only the first component of a complete ELR barrel/cartridge system.

    Best,
    Noel
     
    Last edited: Mar 3, 2009
  12. RockZ

    RockZ Well-Known Member

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    Noel,
    Good to see you over here now. This is the site to fine tune your hunting projectiles without a doubt. Many great hunters and very knowledgable shooters. They will appreciate your work.
    I'm looking forward to getting my 300wsm up and running to shoot your 30cals to optimize the efficiency of an already efficient cartridge.
    The oxygen free copper expandables should be awesome for hunting as well.
    It is going to be an interesting project.
     
  13. noel carlson

    noel carlson Well-Known Member

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    Hello Rocco,

    ... And thanks for the welcome.

    I expect imput from participants at this site will aid greatly in development of dedicated VLD hunting projectiles.

    -Noel
     
  14. JeffVN

    JeffVN Well-Known Member

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    Do we have any new information on these tests? I'm still waiting for the gaint-twist barrel for my 338LM Improved, so I've not started testing yet.....

    I did receive my GS Customs 295 grain banded solids, which are only slightly shorter in overall length then the 318ZA that Noel sent me to use as a mock up bullet for getting my reamer cut (that is still in the works too, but is expected back very soon).

    JeffVN