fastest 338 without the Cheytac

Discussion in 'Long Range Hunting & Shooting' started by trueblue, Sep 18, 2010.

  1. trueblue

    trueblue Well-Known Member

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    I have a friend contemplating a 338 build with the following criteria:
    -rifle to weigh no more than 10 1/2 pounds
    -28" barrel
    -able to take game at a mile. ( he has already taken game at 1350yards)
    I know the EDGE will do it, as I have seen where Shawn posted a kill at over a mile, but my friend is lookinfg to get alittle foregiveness on the wind read with something faster.
    The Cheytac case is out as it will push the build over his weight limit, as this will be a carry rifle.
    I would like to get some feedback based on this criteria.
    Will the Lapua AI or EDGE AI be the ticket, or would going to the 338-378 Weatherby ?
    All coments welcome.
     
  2. MT4XFore

    MT4XFore Well-Known Member

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    I believe Kirby's (Fiftydriver's) 338 AX built on his Lightweight Raptor action will fill the bill for you nicely. I'll let you know when I get mine.

    Jim
     

  3. winmag

    winmag Well-Known Member

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    Ya Id bet one of Kirby's hot rods would fit the bill. AX, or AM. But the 338-378 would probably work too.
    Im sorry Im not more current on hot rod 338's, but Kirby and LTLR have a ton of experience with them in just about any configuration ever concieved I think:D.
    Maybe one or both will chime in soon..........
     
  4. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    Sent a long pm. But basically the 338-416 imp is about the best for a mile and only 150 or so fps off the chey-tac 338 wildcats. The 378 imp is right there also. The fastest one I ever worked with was the 338-416 imp. Problem is it will not fit the criteria as well because of the weight limits. It is nearly impossible to shoot a light rifle accurately at a mile. The lapua wildcats do well in shorter barrels much more so than the big 378 and 416 cases. A beefed up 26" barrel may be in order on a lapua based wildcat that loses very little velocity and retains accuracy well in the shorter barrels. A 28" barrel that stays within the 10 1/2 pound criteria I think will be to flimsy to go out to a mile. A beefed up 26" tube may fit the criteria better. The 338 norma on the shortenned lapua was designed for just this purpose and may be worth looking into. I have never shot it.

    My improved 338 lapua got right at 3000 fps in a 28" barrel. It was very similar to the one kirby does with the shoulder pushed slightly forward and blown out with a sharper shoulder angle. I think I could have got 2900 fps with it in a beefed up 26" barrel and been deadly. That is where I would go I think. Be an interesting build. Like I say the rifle can do it but to shoot that light a rifle accurately at a mile would be extreme.
     
  5. jmden

    jmden Well-Known Member

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    http://www.longrangehunting.com/forums/f19/338-416-rigby-37559/

    Some comments above. Seems like I typically see Kirby talk about getting 50-75 fps or so more out of the 338-378 Weatherby than the 338 Lap Imp, but brass life is apprently terrible as it's soft AND it's expensive. From what I gathered, I'd probably go with the 338-416 Rigby (no belt, not that that is much of a big deal, just size to headspace off the shoulder, not the belt) over a 338-378 Weatherby, but I'd still take the 338 Lap Imp or 338 Lap AI over the others. My 338 AX is pushing the 300SMK at 2980fps out of a 30" barrel over 102g Retumbo and Kirby's 'modified hybrid' throat. Good enough for me and I expect many reloads. Just took my first big game animal with it last week.
    http://www.longrangehunting.com/forums/f84/washington-state-high-buck-hunt-2010-a-61184/ I thought about this build and asked alot of questions for alot of years. My rifle is probably right at 10.5 lbs w/o the NF NSX--every component ('cept the NF) was carefully picked to be as lightweight at possible and still be a lr hammer.
     
  6. Autorotate

    Autorotate Well-Known Member

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    Jim/Trueblue

    Can you clarify if the 10.5 lb is with optics, ACI, level, bipod, sling, and if a carbon barrel is in the budget?

    The 338 Excalibur will be the largest piece of brass you can put a bullet on top of without going to a Cheytac class action. 3082 fps with a 300 SMK and a 31.25" barrel was were accuracy was found for mine using H50BMG. US869 and WC872 yielded more velocity potential, but I haven't invested the time to see where accuracy came together for those powders and that cartridge.

    Jamison now makes brass for this round. I got dies from Neil Jones. Simply stated, it holds 140 grains of water vs. 126 in my 40 deg 338 LMAI. In longer barrels/slower powders, it will outstep the Lapua Improved. In shorter barrels, the velocity advantage slims down some, and if you factor in the cost/brass life of the Lapua brass vs. Jamison, the edge goes to the Lapua in a 28" barrel.

    I believe Dave Viers has built some 11 lb Cheytacs using carbon barrels and Lone Wolf Stocks, so you may want to give those folks a ring before ruling out the Cheytac option for your goals.

    Since he's already connected at 1350 yards (hats off to that, as that is a ways, and involves many variables that he's obviously has nailed down), he probably also realizes that at those distances, each 100 yards becomes a new monumental task to be successful at cold bore first round hits. I know I simply don't have the skill (yet), to manage recoil of a 10.5 lb rifle for 1350 yards cold bore first round hits.

    For now a rough rule of thumb I've come to appreciate when building a rifle towards a specific precision goal is.... 100 yards for each lb of rifle (ready to shoot), so a 1 mile gun for me, would need to come in around 17-18 lbs. My 30-338 Lapua pushing a 210 Berger at 3300 fps comes in at 12 lbs, and I feel confident with it in ideal conditions to 1200 yards. The 338 LMAI is a new to me rifle, but it comes in around 14.5 lbs, and I can see me capping it's potential at 14-1500 yards. There's just a lot going on during that recoil impulse to manage perfectly everytime in my book...especially when you're talking 300 grain bullets at 2800-3000+ fps. Certaily there are folks that can shoot light rifles way out there, I'm just not that good. This is just my two cents, not looking to mash any toes, or offend any light rifle LR shooters/hunters.

    I'll post up some more once you post the answers to the questions I posted on the first line of this lengthy post:)
     
  7. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    Autorotate, I thought about the excalibur although I have never shot it. The reason I didn't list it is because like the 378 and 416 case I feel that it would not do as well with the short barrel as the lapua based wildcats. Those big powder guzzlers are for sure the best ones to shoot a mile with but like long barrels to utilize all that slow burning powder. The efficient case design of the lapua based wildcats may be better in the short barrel required to meet the specs. I have experience with those and they do very well with the short barrels. I am not familiar with the carbon barrels being accurate enough to shoot a mile either. I think it may take a fat 26" barrel to be most accurate at a mile and that would require a very efficient case design. I am no guru on this but offer that opinion. If the carbon barrels work out they will be the go to thing for light hunting rifles with long range capability. But like I said, it is extremely difficult to shoot a light rifle long range.
     
  8. Autorotate

    Autorotate Well-Known Member

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    LTLR-I certainly defer to your and others more experienced on these big bores...as I've only got 3-4 years at this LR thing vs. others on this board. But I do try and actually shoot just as much as I can at distance.

    I agree with you on the point of the Excalibur being suited to longer barrel lengths, and certainly alluded to that previously, but just to recap... given a 28" barrel, the Lapua case seems like a better fit for sure.

    This would seem to be a good template for 10.5 lb carry rifle..., put a 225/250 NAB on top of a bunch of Retumbo/H1000/Ramshot Magnum, and call it good for anything in NA under a 1/2 mile. I think you've built a bunch of these type rifles if I recall correctly....338/378s pushing Gamekings/Accubonds/Partitions fast and flat.

    And that's the second point I agree with you on....10.5 lbs and one mile I believe are two goals opposed to each other.

    But that's the fun part of this I'm sure for this build...is getting all the components/specs of the build to compliment to the goals of the rifle!
     
  9. trueblue

    trueblue Well-Known Member

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    The rifle will weigh no more than 10 1/2 #, total weight with NXS on it would be 13#, so in that weight class, I think a mile is doable.
     
  10. trueblue

    trueblue Well-Known Member

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    There seams to be a trade off to be reached with these longrange carry rifles between weight, fps, downrange energy, ect.
    On one hand you need a big case like the 338 Cheytac to have 1500# of energy at a mile, but the weight of the rifle is to heavy to carry on your back all day long.
    The lighter builds like the 338 Norma/Lapua/EDGE can be done in 12 1/2# all up, but does not carry the payload of 1500# at a mile.
    Then you need to also think about the wind advantage of each cartridge.
    Between the 300gr SMK going 2750fps vs. 2950fps there is only 14" less wind @ 1500 yards from the faster case. That is only an improvement of 10%.
    So it seems you would need to jump up to the Cheytac case to get a real advantage in wind trajectory of say 20-25% with the 300gr SMK going 3200fps.
    The other issue is recoil. Shooting the 300gr SMK faster is going to generate more recoil and be felt more in a lighter rifle, and be harder to shoot accurately in a lighter rifle.
    So, where is a good balance of all this between energy, recoil, rifle weight, and wind trajectory?
     
  11. jmden

    jmden Well-Known Member

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    That's right where mine is. You can see build specs and a pic at the link in my post above. From what I recall, a carbon wrapped barrel would've save me about 1/2 lb over the heavy fluted med. Palma 30" barrel. That's the number I recall, but that was awhile ago. I'll probably go with a bit shorter barrel (28"--it'll be intersting to see if any of the new Superformance powders push the 300g bullets faster...) and a carbon wrapped barrel when I rebarrel this. I'm the kind of guy that literally counts ounces--less ounces equates to more fun!
     
  12. trueblue

    trueblue Well-Known Member

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    Thanks for the link, jmden.
    And congrats on your hunt. Enjoyed reading your story.
     
  13. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    Trueblue hit my point exactly. In a light rifle the big 338's kick to hard to be accurate at a mile with a 300 grain bullet. That is why I was thinking a lapua wildcat with much less powder and still decent velocity. Still the big excalibur, 378 and 416 cases will get more velocity with a short barrel but the recoil is my concern.

    Autorotate, Your right on with my rifles and what I try to do. My big guns weigh 10-11 pounds scoped out and ready to hunt. They are good to about 1200 yards. I shoot primarily the lighter bullets extremely fast and keep most shots inside a half mile where this type rig will outperform anything. I have taken game to 1100 yards with light bullets going very fast. My pet 338-378 for the light bullets has a hart 28" barrel and weighs 10 3/4 pounds scoped out. It shoots the 225 accubond 3500 fps and took an elk easily two years ago at 910 yards. Easy shot shooting that flat and accurate. Antelope last year at 813 yards.

    I have basically the same rifle set up with 300 matchkings at 3060 fps for long range. Again 28" barrel and 10 3/4 pounds scoped out. This summer I got out to 1500 yards with it at elk size targets. The rifle did the job out there but it is extremely difficult to hold that much recoil accurately at that range and the barrel gets mighty flimsy to group that far out. But I would not completely rule out the excalibur, 378 or 416 case for trueblue. With the excalibur or 416 improved I am sure 3000 fps is doable in a beefed up 26" barrel that would kill an elk at a mile if a guy was good enough. Again a 28" barrel gets flimsy in a rifle that light shooting that far.

    It is all give and take but the barrel has got to have enough beef in it to hold a group at that range first and foremost. Then you got to consider the cartridge that can kill efficiently at that range.

    My 338 RUM has a 26" barrel and will shoot the 300 smk 2730 fps at best accuracy. But there is a whole lot of difference between 1200 yards and 1700 yards. In my opinion a guy would have to go through several rifle builds to get a rifle that has the accuracy in that light of a rifle to shoot one mile. Then the shooter would need plenty of practice with the rifle working his technique to get out that far.
     
  14. Autorotate

    Autorotate Well-Known Member

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    I'd be very impressed to see a cold bore hit on a 1 MOA size target at 1760 yards with the 13 lb rifle. That's some good shooting for sure in my book.


    One way, but certainly not the only way to meet the requirements of:

    10.5lb rifle/13lb finish/1500 ft/lbs of energy at 1760 yards given an atmosphere of 60 deg/4000'/50% humidity.

    Bullet 1-RM 275 grains @ 2975 fps fits your energy requirements. Delivers 39 ft/lbs of recoil with a 100 grain charge.

    Bullet 2-Berger 300 grain @ 2985 fps delivers the energy your after, but pushes back with 44 ft/lbs of recoil with the same 100 grain charge.

    Bullet 3-Sierra 300 grain @ 3165 fps delivers the required energy, but this velocity level bumps the recoil up to 47 ft/lbs.

    All those numbers where using the JBM online calculator/data.

    In summary, given a 28" barrel, your looking at pushing the limits of performance of the largest 338 cases, shooting the highest BC of bullets. The high BC of the 275 gr RM bullet above, looks like it might have the best potential of doing what you want it to do.

    The 338 LMAI in the pic below is 14.5 lbs. If you used a MK4, you could save a 1/2 pound...it pushes a 300 SMK at 2920-2930 fps with a 28" Brux Medium Palma using 102-103 gr of Retumbo. That case ought to be able to come close to pushing a 275 grain bullet to 2950-2975 fps as per the energy/recoil analysis above.

    [​IMG]
     
    Last edited: Sep 19, 2010