Reamers ordered for new cartridge .378 Sniper-Tactical

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Black Diamond 408, Aug 18, 2006.

  1. Black Diamond 408

    Black Diamond 408 Well-Known Member

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    After talking with some people in the know, Sierra is making a Match King for the 375cal. (around 350grns)
    My original design to wildcat the 408 C-T case was to be a .375cal, but no real good long range bullets were avalible at that time so .338 got the call. Early tests from others have proved this cartridge will surpass all expectations. Using the special Lost River bullet (350grns) for this cal, groupings at 1500yds has been sub moa. The case design will be the same as my .338 snipe-tac, just with the larger neck dia. Some time this winter i will have a functioning single shot rifle(carry weight). I am thinking the 350grn .375cal bullet should hit speeds around 3300fps.

    Specs:

    Viersco 700 style action "Lightning series" 4.5#
    100% carbon fiber stock, Lone Wolf tactical 22oz.
    ABS carbon wrapped barrel, 30" with Ti muzzel brake 5#
    Mike Rock bbl
    30moa picatinny rail base
    Nightforce 5.5x22x50 NPR-2
    Twist rate, 11, 11.5 or 12 unknown at this time.

    Estimated weight 12# without optics

    Check my website for updates and photos.

    Dave
     
  2. davewilson

    davewilson Well-Known Member

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    this is music to my ears! i've thought about this cartridge for close to 2 years now and to say i want one is an understatement.

    is your case an improved version or a standard chey-tac?
     

  3. Black Diamond 408

    Black Diamond 408 Well-Known Member

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    Dave,
    I am using the same specs as my 338 snipe-tac case, the case has been improved to 35deg shoulder angle with some of the body taper removed. They are very easy to fire form and neck down, they re-size easy and extraction after firing is very good too. The first step from 408 is to 375 so it is only one push through the sizer form die. If i have a chance this weekend i will post a pic with a 375 bullet seated in the case.

    Dave
     
  4. davewilson

    davewilson Well-Known Member

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    a picture with other bullets will only be a tease until that SMK is in there. i heard about this a while back, do you have any time frame info when the 375 MK will be available? i heard chey-tac was trying to get sierra to introduce a 375 so they could start manufacturing a 375/408 tac.
     
  5. Black Diamond 408

    Black Diamond 408 Well-Known Member

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    Dave;

    Yes that is what i was told, Chey-Tac is comisioning Sierra to design a Match King bullet for the new 375-408cheyenne tactical cartridge, suspect it will be the bullet offered in their loaded ammo. I was told that there will be some test bullets arriving soon. Lost River Balistics designed a special bullet for this caliber also, this is one of several bullets they have been testing. As we all know the LRB bullets are monolithic and $$$. They have been testing the accubonds with very good results. I was told at 1500yds the groups were 10-15" across the spectrum of bullets tested. The LRB bullet had the least amount of MOA needed.
    I have no idea when the bullets will be avalible. I think they want to test a range of weights and see what works the best. 325-350grns is the range they are looking at.
    Here is a pic of a formed 378 snipe-tac case and a std 408 case for comparison. The bullet is just a plain Sierra.
    I may order a box of the LRB 350grn for testing later on.

    [image][​IMG][/image]

    Dave
     
  6. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    BD408,

    Great minds think alike I suppose. There is a 375 AM reamer on the way as well!!! Like you I was waiting on bullets to make this a go. THis is good news.

    I am getting 3300 fps in my 338 AM with a 350 gr ULD RBBT so I suspect you will easily push that level in a shorter barreled, larger bored 375 bore.

    I would prefer a bullet of heavier weight than 350 personally. I am talking to Richard about a 375 to 400 gr class bullet. Ballistically, I think the 300 gr SMK 338 bullet will equal or surpass what a 350 gr 375 cal will get as far as BC and I know the 350 gr ULD RBBT 338 bullet will top the 350 gr 375 bullet in BC.

    Still, its a good start for sure!!! THey must be listening to someone out there. Its about time Chey Tac looked into an accurate lead core bullet design. They should have done it with their 408 and it would be much more popular then is currently is.

    Just my opinion though!!

    Keep us posted to your new moster. I think I am just going to put another barrel on my light weight 338 AM when it gets finished in 375 AM.

    At that point I will have a 338 AM, 375 AM and 50 AT switch barrel rig!!!

    Good Shooting!!

    Kirby Allen(50)
     
  7. speed demon

    speed demon Well-Known Member

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    They should get sierra to make a 400gr .408 matchking also..
     
  8. Black Diamond 408

    Black Diamond 408 Well-Known Member

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    Sierra said they wont make one that big. Richard is supose to have the dies on order to make them.
     
  9. MachV

    MachV Well-Known Member

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    Wo Hoooo FINALY a long rang 375 bullet,maybe the Mach V will show its stuff.Ben known to get 5000fps outa the little 260s.I wonder if the 300 Sierra's will take the heat?

    [​IMG]
     
  10. Northman

    Northman Well-Known Member

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    Any clues about the BC of the new bullet?
     
  11. Black Diamond 408

    Black Diamond 408 Well-Known Member

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    Norhman,
    I was told they will be around the same as the 300grn 338 version.
     
  12. davewilson

    davewilson Well-Known Member

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    BD, i'm gonna ask the next logical question and i'll be a little surprized if you haven't already made a dummy round. let's put this thing on a spotter case. the shortened 50. i think the 375 cal will be enough to let it breath with around 180 gr of powder.come on,show us a picture of the 375 shorty!
     
  13. Black Diamond 408

    Black Diamond 408 Well-Known Member

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    Dave,

    No i haven't done that! I have seen it done before, Lilja's website had the reamers for it. I am in the process of building a 408 spotter imp. A improved spotter case will hold 200grns of powder, i dont know how well a bbl will hold up to this amount of powder down a 375 bore. If and when some High BC bullets become ava for a 45cal this would be another one for the spotter case. Even a 50cal Amax should be very effective, specially for the california dudes! Below is a pic of a 408 in an improved spotter case, a standard 50cal spotter loaded with a 750Amax and a 50cal BMG round with the same 750Amax bullet. My improved case only features the shoulder angle changed to 35deg and shoulder pushed foward, the case taper was not changed. 50cal Short Mag? almost the same results in a smaller package. I look for the 408 version to be outstanding. I feel the 40cal bullets are the smallest dia for case-powder ratio to bore size that should be used.
    [image][​IMG][/image]

    Dave
     
  14. davewilson

    davewilson Well-Known Member

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    that's why i would stay with the regular spotter case, would have 170-180 gr of powder and 375 bore.pretty close to the ratio you have with the 408.