375-408 Cheytac

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by nochmehr, May 2, 2007.

  1. nochmehr

    nochmehr Member

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    Hello everyone, I'm new at this forum.

    I have heard about the 375-408 Cheytac, and I wish to gain more information about this caliber. So I have a few questions that I hope you can answer:

    1. When does the 375-408 get subsonic? I have heard that it remains supersonic out to 3000 yards, true?

    2. How is the 375-408 affected by wind compared to the 50BMG?

    3. What is the bullet drop compared to the 50BMG at 1000, 2000 and 3000 yards?

    4. Can a good marksman shoot smaller groups than 1/2 inch at 100 yards with the 375-408, or is it ammo-limitations that prevent this?

    5. Can the CheyTac M310 be ordered in this caliber?
     
  2. Black Diamond 408

    Black Diamond 408 Well-Known Member

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    Welcome to the board!

    1. Reports i have seen it breaks around the 3000yd zone.

    2. The 375 will surpass the 50bmg in all catagories except for energy.

    3. I cant ans the bullet drop info

    4. 1/2" groups or less should be acheived easy with quality componants. Shooting skills would be a big help too. there are lots of variables here. My 338-408 will shoot in the .2's at 100yds

    5. This question you would have to contact Chey-Tac. I would just have it built to your specs, use a competant gunsmith that is familar with the 408 case.

    I have seen the test results from the new Sierra MK bullets that are designed for this case, they are very impressive. A test group was fired at 2400yds, i belive it was a 16" group. The bullet is still in testing, 350grn right now, it may go as high as 375grns.

    I have the reamer for the 375-408 improved...curently working on the test rifle. It is called "375 snipe-tac"

    Are you looking for a single shot or repeater?

    Dave
     

  3. nochmehr

    nochmehr Member

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    Thanks for a great answer, Black Diamond 408.

    I am not going to buy a 375/408, I'm afraid that I can't afford it right now. But maybe one time in the future /ubbthreads/images/graemlins/wink.gif Right now, I use a custom-built 338 Lapua Magnum rifle with a S&B PMII scope for long range shooting, and I really like that rifle.

    Do you know about any pages where I can read more about the 375/408, and the 375 Snipe-Tac you mentioned? I think SOE is the right place, but it seems like the site is down right now /ubbthreads/images/graemlins/frown.gif
     
  4. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    I will also have my 375 Allen Magnum out this summer as well.

    Biggest problem with the 375 cal is a supply of good long range bullets, or lack there of. You really need a bullet with a BC of over .8 to be competitive with the 338 rounds as far as ballistics go.

    Currently you have the Lost River Ballistics bullets if you want to pay $2 each for the bullets. Chey Tac I believe also has a couple bullets they are testing.

    Sierra has made a test run of 350 gr SMKs for Chey Tac industries to test in their 375-408 but I have already heard that this bullet is to be redesigned into something like a 375 gr version which I have been calling for for over a year now.

    Wildcat Bullets is also tooling up to build heavy 375 cal bullets and with some new developments with Wildcat bullets, I suspect the new 375 gr pills may be the ultimate in ballistic performance yet still offer good consistancy in a wide range of barrels and also offer great terminal performance, things the LRB bullets simply do not offer, no solid long range bullet can offer these things.

    I am also designing and will be releasing a 375 Allen Xpress which will be based on the 338 Lapua case which will be a bit tamer then the 375 Allen Mag for those that want to play with the medium bores but not get as extreme as working with the 408 CT case.

    Right now, the best place to learn about these will be from Chey Tac Industies, Barney Lawton with Lawton machining and here at LRH from Dave and myself when we get our wildcats throwing lead.

    Ballistically, the 50 BMG is really a dog compared to these rounds in every catagory except energy but they have plenty to get most work done easily.

    Energy wise, the 375 will pack a significantly heavier load then the 338s.

    Again, the limiting factor at this point is a good choice of accurate long range bullets but they are coming!! I have a supply of the 375 cal sierra SMK bullets on the way for testing and I can not wait to try some of the new WIldcat bullets when they are ready!!!

    Personally, with the correct bullet, I feel the 375 cal on the 408 case is a better choice then the 338 version. Simply because it will be less finicky, can use much more common powders, has a longer bore life and is easier to form.

    Thats another point, working on offering formed cases to my customers for the 375 AM and 375 AX as well. That will be ready by this summer.

    Good Shooting

    Kirby Allen(50)
     
  5. nochmehr

    nochmehr Member

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    Hello guys, I have some more questions about the 375-408 round. First of all, where do you recommend to buy this gun? I think its clever to have a professional gunsmith build it for you, who is recommended?
    A question about the case itself, where do I get it? Its a necked down 408 case, so its not the same case is it?

    I want you to know that I'm not going to buy a 375-408 rifle yet, my 338 Lapua Mag is very good for long ranges, but when I start shooting at more than 2000 yards, the 375-408 will be the top candidate.
    One final question, just of interest, do you think the 375-408 cartrigde will be used for military extreme-range shooting? Special forces, as Delta Force and Special Air Service, may become very interested in this round dont you think?
     
  6. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Chey Tac is working on their 375 CT right now so they may offer brass in the future but at this time you have to get 408 CT cases and neck them down to 375. Not a big problem.

    Only way to get a rifle in this class of chambering is to have it custom made. I make my 375 Allen Mag, Dave Viers is supposed to be making his 375 Sniper tac soon. I do not know if Chey Tac has their 375 available for customer orders yet or not. I would suspect not since they still have not gotten the bullet situation figured out yet.

    Just a side note. Everyone thought the redesigned Sierra MK 375 bullet would be in the 375 to 380 grain weight range, that will not be the case, Sierra has told Chey Tac that they will not make a 375 bullet heavier then 350 grains so all they will be doing is using a heavier jacket on the original 350 gr SMK design to handle the added velocity strain. That is to bad.

    Wildcat Bullets will be making some heavy 375s in the future as well but that may be a ways out yet.

    The 375-408 has alot more potential for military use then does a 338-408 simply because of the longer barrel life.

    That said, getting the military to adopt any new round is nearly impossible so do not expect to see it anytime soon. To be honest, the 408 CT had the best shot at being adopted in my opinion simply because of its user friendly personality but accuracy issues killed that round and I suspect we will not see the military using any of these anytime soon unless its a special forces type deal where the men can choose what weapons they want to use if that is even possible.

    Good Shooting

    Kirby Allen(50)
     
  7. Aragorn50

    Aragorn50 Member

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    [ QUOTE ]
    Chey Tac is working on their 375 CT right now so they may offer brass in the future but at this time you have to get 408 CT cases and neck them down to 375. Not a big problem.

    Only way to get a rifle in this class of chambering is to have it custom made. I make my 375 Allen Mag, Dave Viers is supposed to be making his 375 Sniper tac soon. I do not know if Chey Tac has their 375 available for customer orders yet or not. I would suspect not since they still have not gotten the bullet situation figured out yet.

    Just a side note. Everyone thought the redesigned Sierra MK 375 bullet would be in the 375 to 380 grain weight range, that will not be the case, Sierra has told Chey Tac that they will not make a 375 bullet heavier then 350 grains so all they will be doing is using a heavier jacket on the original 350 gr SMK design to handle the added velocity strain. That is to bad.

    Wildcat Bullets will be making some heavy 375s in the future as well but that may be a ways out yet.

    The 375-408 has alot more potential for military use then does a 338-408 simply because of the longer barrel life.

    That said, getting the military to adopt any new round is nearly impossible so do not expect to see it anytime soon. To be honest, the 408 CT had the best shot at being adopted in my opinion simply because of its user friendly personality but accuracy issues killed that round and I suspect we will not see the military using any of these anytime soon unless its a special forces type deal where the men can choose what weapons they want to use if that is even possible.

    Good Shooting

    Kirby Allen(50)

    [/ QUOTE ]

    Very true about the difficulty getting a new cartridge adopted by the military. The only chance is within SOCOM. The 408CT was not adopted as it failed in part due to the way the CT folks were marketing it. They pushed it to be a replacement for the 50BMG, when it did not have any ability to deliver a "payload" as the Mk211 Mod0 ammo does. It is also exceedingly difficult to get the "Big Army" to adopt a new cartridge/caliber. I believe the Navy (NAVSPECWAR) is moving toward the 338LM, but you have to understand that this is already a NATO standard round, and already has a number of versions of Tracer, AP, etc. The folks at CT tried to sell the 408 as a wonder weapon, and couldn't get it to do the things they were claiming unless the loaded at 70,000+ psi, and shot it at altitude. I got caught in the middle of some of the discussions over this..... It is a very capable and interesting round. However, those who thought the US Military establishment would or should jump on this and spend the BILLIONS it would take in R&amp;D to bring out multiple variants to "replace" the 50BMG were fooling themselves.

    I want to build a rifle on some variant of this case, but there is no way in my lifetime it would ever replace the antimaterial capabilities of the 50.

    Scott
     
  8. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Scott,

    In the latest issue of VHP there is an article talking about my 50 Allen Tactical, basically my 338 Allen Mag necked up to 50 cal. Based on the 408 CT case it is getting legit 2450 fps performance with upper end pressures. My idea was to market this toward the military as well to those units using 50 BMG rifles that are big and heavy.

    I can chamber my 50 AT in rifles that weigh as little as 15 lbs and with a quality suppressor would be much more enjoyable to shoot then say a 25 lb 50 BMG.

    Anyway, I agree with your comments, breaking into the military market is extremely difficult, even with a good product.

    Kirby Allen(50)
     
  9. Colcalcipherol

    Colcalcipherol Well-Known Member

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    Uncle Sam is making very good use of the .408 CT these days so their considering another variant is not likely.

    Question for Kirby and Dave: In your .375/.408 variants, what twist rate do your use? I'm looking at building one but going 29-30" with a 1:11 twist.