408CT based calibers

Discussion in 'Long Range Hunting & Shooting' started by Spanners, Jan 27, 2009.

  1. Spanners

    Spanners Well-Known Member

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    Those that were playing around a couple of years ago with 338, 375 etc 408CT wildcats, how are they still running.
    Whats the barrel life like and have the mfg finally got onto of a good projectile?
     
  2. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    The 338 based wildcats on the 408 case are main stream. To my knowledge, there are no less then five of them available to the public, 338 Chey Tac, 338 Extreme, 338 Sniper Tac, 338 Big Baer and my 338 Allen Magnum. I am sure there are others but these are the ones mentioned most here on LRH.

    The 375 version also has several options, 375 Chey Tac, 375 Sniper Tac and my 375 Allen Magnum.

    As far as the 408 caliber, there is basically two, the 408 Chey Tac and my 410 Allen Magnum.

    My 338 AM is quickly becoming my most popular chamber request only surpassed by the 300 RUM and 338 Edge in popularity.

    Barrel life is really hard to predict. Depends on so many variables its hard to say. In my testing, the 338 AM will get you around 600-900 rounds of accuracy life per barrel if its cared for. This all depends on how the rifle is used. The harder cut rifled barrels will tend to offer a bit more barrel life.

    The 375 cal will be significantly more, I would say 1500 easily of the barrels are not abused.

    408 versions should go well over 1800 rounds if cared for properly.

    Projo wise, the 300 gr SMK is the go to bullet for the 338 versions. There are a couple more options coming on line from Hornady and Berger but they are not ready yet.

    For the 375 cals, there is the 350 gr SMK available from CHey Tac.

    EDM is offering some lead core match bullets in the 408 as well.

    There are several solids being made and some custom bullets made in all calibers but they are not mainsteam yet.
     

  3. BountyHunter

    BountyHunter Writers Guild

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    You might find that the door is still open on the 375 in particular.

    Several guys I know playing with it do not like the current 350 gr version as they say it needs to be at least 360-375 gr and much longer but it limited to only 350 due to manufacturing restrictions. Until a better bullet, it might be limited.

    The 338 field is much more open and Berger is planning on 6 more 338 bullets this year and Hornady is supposed to there with one.

    Take your pick of cartridges.

    BH
     
  4. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    First time I saw the 350 gr. 375 cal SMK I was less then impressed. I though what a waste!!! Huge boattail, very little baring surface and really not much longer then a 300 gr SMK 338 cal bullet. I figured BC would be in the .6 range if it was lucky.

    I think I even posted my feelings about them when I first saw them. I then contacted my contact at Chey Tac Industries and asked them what their tests were showing for a BC for the new bullet. They told me roughly 0.770 in their tests with their 375 Chey Tac launched at 3000 fps.

    There was no way this bullet would make the same BC as Sierra listed for the 300 gr SMK 338 pill.

    Loaded some up and worked up a load that averaged 3295 fps in my 338 AM. Just because thats what they said, I used a BC of .770 in my drop chart and headed out to test it. To my great surpise, it was dead on the money out to 1500 yards which is the max I tested it to. From 500 to 1500 yards it was dead on.

    In my testing with my 338 AM, I find I have to use .800 for the 300 gr SMK to get drop to match up with the predicted computer numbers. So while its not the full equal to the 300 gr SMK in BC, its damn close and much better then I ever expected it would be.

    I have pushed for a long time to get a 375 gr BTHP match bullet and recommended that to Chey Tac but they said Sierra would not order in the longer dies needed to make the longer bullet.

    To be honest, I would be even happier with a 350 gr aluminum tipped bullet with a BC in the .9 range. Keep the speed, boost the BC, win-win, especially with the Sierra jacket that will take pretty much any velocity you can throw at it.
     
  5. Spanners

    Spanners Well-Known Member

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    So to cut a long story short, forget anythign bigger that 338/408 as at the moment as the pills arn't up to scratch??

    A few questions.. quite a few. :)

    Is anyone seeing 300 SMKs to 3500fps reliably with ANY barrel life similar to that described by 50Driver?
    50 - when you state 6-900 rounds of 'accuracy' what is the expected accuracy, and when it 'falls off' to what extent and how quickly?

    Is it the 1st 3 inches of throat that is rooted, or is the whole barrel toast?

    I;m looking at a receiver.. its single loader, no ejector, and weighs 58oz... would like something that is a bit lighter if possible and a repeater... aiming for a 11-14 lb rifle less scope etc if achievable.
    Whats a nice cost effective option given the arse in our exchange rate?

    All the different 338/408 wildcats, are there any 'actual' differences other than a couple of thou here and there in the reamer prints to make them 'different'?

    Cheers! :)
     
  6. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Why are you giving up on the 375 cal. Not saying its better but the 350 gr SMK will do anything the 300 gr SMK will do in 338 and do so at same velocity with larger frontal area and higher kenetic energy payload.

    Also an increase in recoil but there is always something that has to give.

    The 375 will also have a much longer barrel life. Not as many bullet options but still a good one. Either will serve you well so do not run from the 375 just because there is only one bullet. If you do go that way, make sure you get a large enough supply that you need not worry about running out.

    In my 40" Black Sunshine in 338 AM, I drove the 300 gr SMK to legit 3500 fps velocity. In fact they averaged 3510 fps. This was with the old TTI brass and it offered pretty good case life, 4-5 firings at this level. The new Jamison brass will not do this but it will do 3400 fps easy enough.

    In my experience, accuracy generally stays at or very close to the 1/2 moa range but once the barrel goes, it goes quickly. In fact dramatically noticable in the three barrels I have burnt out.

    My rule of thumb when setting a barrel back is that you cut off the entire chamber including throat and then rechamber. In the case of the 338 AM, you will clean up roughly 4" of barrel length which mostly will clean up the severe heat cracking but you will still have some.

    I have also noticed that if a virgin barrel will get you say 800 rounds of accuracy life, when you set the barrel back and rechamber, you will get around 50% of that original barrel life so expect another 400 rounds before things really start to fall off. Is it worth it, your call. The damage is down the entire bore, or should I say wear. This is why the next round will not have as long of an accuracy life as the original chambering.

    You may possibly get into the 14 lb range with a repeater but it will not be easy. You will need a carbon fiber stock, slim barrel contour, likely no longer then 30-32" and you will still be pushing things pretty hard.

    Its MUCH easier to get there with a single shot. My BAT based Xtreme Heavy Sporters can start at around 16 lbs ready to hunt with including a NF NXS 5.5-22x 50mm scope and harris 9-13 bipod. Its hard to get much lighter then this and retain long range consistancy. These rifles really put a strain on a rifle system. They need the receiver, stock and barrel integrity to handle it and remain consistant.

    The Chey Tac rounds are the smallest capacity of the group and Chey Tac loads them pretty mild.

    The Sniper Tac, Extreme and Big Baer are all very similiar in performance and roughly 100 fps step over the standard Chey Tac. They are also very easy to work with as there is no extreme case forming, just load and shoot.

    My 338 AM is the largest capacity of the group. Shoulder location is moved forward to stretch the body section and increase case capacity. This can do a couple things for you, give you around 75-100 fps more velocity on the top end with same bullet and barrel length, or match the slightly smaller 408 based chamberings with a bit less pressure which will offer longer barrel life to some degree.

    From the low end to the top end, there is only 200 fps difference between them all and from what I have seen, all are extremely accurate at nearly any range your bullet remains super sonic so you could really not go wrong with any of them.
     
  7. Spanners

    Spanners Well-Known Member

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    Thanks 50.

    I have looked for the 375cal SMK, but don't see it listed @ Sierra, hence why I discounted it.

    Do you have reamers for sale for the 338AM?

    The receiver I'm looking at is 3.5lbs- single shot.. going to have a to look around for something a little lighter I hope
     
  8. Kiwi Greg

    Kiwi Greg Well-Known Member

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    Hi Spanners, I'm starting to think about a new toy already, before the current one is finished. :D

    Looking at the same sort of thing as you as my current build won't be portable enough for hunting properly.

    Will be interested to see what you come up with.

    Cheers Greg.
     
  9. Jase

    Jase Member

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    With all said, which of the big fast .338's is the best? Can I get lots of brass and where? How about dies? Where is the best place to get a reciever? I am
    not wealthy. Is there much practical difference between them and the .338
    Edge out at 12 to 1500? At what range would the bigger cases be better?

    Thanks a bunch- I need help, Jase.
     
  10. AJ Peacock

    AJ Peacock Well-Known Member

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    Practical difference? The difference between my Edge and my Allen, is between 1/3 and 1/2 less wind drift depending on the particular situation. Also,5 pounds and 8" overall length. My Edge runs the 300SMK at around 2750fps and my Allen at around 3250fps. A real difference of 500fps! I consider my effective/confidence range to be about 300yds further with the Allen, but due to barrel life, I shoot the Edge a lot more. But the Allen is more FUN to shoot because it is so much bigger/louder etc.

    AJ
     
  11. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Its really hard to compare these two levels of performance looking at the numbers on paper.

    The Edge is a hell of a round. For an all around long range high performane 338 magnum, its hard to beat and is at home in almost every situation.

    Its easy to load for, good barrel life, no fireforming needed, consistant and hits very hard.

    Really nothing to pick at with this one. Its only possible negative is that its best loaded with the bullets seated to the 3.80 to 3.9" range, pretty long. Still, thats really looking hard for something to bitch about as this is easy to work with with extended mag boxes.

    The 338 AM, well, the performance is undeniable, its just a power house but until you see first hand the difference in the field its hard to explain. When one shoots at 1000 yards with a conventionally chambered 338 magnum, its not overly difficult to hit your targets but there is some lag time from trigger break until impact, it is 1000 yards though right.

    With the 338 AM, it seems like your shooting at 500 yards. With top loads the bullet seems to get there dang near with the break of the trigger. Now obviosuly it does not but in comparision to even the largest of the conventional 338 magnums, there is really no comparison as far as time of flight.

    Already mentioned is the reduction in wind drift because of this shorter time of flight. This is what makes hitting smaller targets at long range so much easier with the 338 AM over conventional 338 magnums. Your estimate of conditions is less critical then with conventional magnums. Please read that as "LESS" critical. Its still critical but your error in mid and downrange condition estimates can be larger with the AM compared to the smaller 338 magnums.

    All that said, the rifles are larger, brass is more expensive and barrel life shorter. There is a price to pay for extreme performance so for that reason, its certainly not always the best choice, in fact the more conventional 338s are ususally a better choice but for those that have a conventional 338 magnum and want to take the next step, there certainly is another step to take.
     
  12. Booney

    Booney Well-Known Member

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    Hey 50 I've heard talk of the 375 chey tec not being as accurate as the 338 any thoughts thanks.
     
  13. Jase

    Jase Member

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    Questions, questions, questions indeed! But I am getting anxious to start my new rifle and I think I am finally getting closer to a decision. I hope you all
    continue to have patience and share your expertise with me.

    1- .338 or .408 ?

    2- It seems like barrel life is very short at 34-3500 fps, so if a person keeps
    them down to about 32-3300 fps is there a marked improvement in barrel
    life? If not, how about 31-3200 fps?

    3- is the .338-.378 W a good option? Barrel life, brass availability/cost,
    performance?

    4- It seems to me that the .338 Edge performs at least as well as the .338
    Lapua and maybe the .338-.378 W, but while much less expensive and easier
    to get brass? True or not?

    5- Will standard .338 RUM sizer die adequately size .300 RUM (.100"longer) or does a person need a special sizer?

    6- I have a good .50 that weighs 26lb's. Why would I want a .408? Is it much
    lighter or more accurate or cheaper to shoot? . 50 brass and bullets are easy to get-
    so far .408 brass looks almost impossible to get and the same with
    bullets?
    7-Now for the critical stuff... Can anyone tell me specific names and addresses
    to get the various .338 brass (.338 Chey Tac - Extreme - Sniper Tac - Big Baer - Allen) that will push 300 gr. SMK's or Lapua's to a
    legitimate 32-3300 fps ?
    8- Where do I find receivers and about how much do they run? Can any of these run in a Model 700 safely and accurately?

    Thanks a bunch in advance for the help-I really need and appreciate it. Jase.