.338 Lapua Mag.

Discussion in 'The Basics, Starting Out' started by paal, Jan 23, 2003.

  1. paal

    paal Active Member

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    Hello.
    Need advice from you...please.
    If you build a .338 LP it's not recommended to use a Remington action. Becuase of the safety...? Not strong enough.
    What about a Rem.700 Safari .416Remmag.
    That should be safe, or not????
    I can get one cheap.
    Choate stock, and Leu.8,5-25X50LRT
    Please advice.... anything help's
    Thank's in advance
     
  2. Guest

    Guest Guest

    paal--
    the .416 Remington uses the standard magnum action. It is not recommended to build the lapua or the large Weatherbys on the M700 action because of the amount of metal that must be removed while chambering these large cartridges. It leaves a thin chamber wall where the action threads are cut, and this is potentially unsafe, especially when hanging long, heavy barrels on the ation.
     

  3. Brent

    Brent Well-Known Member

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    Paal,

    Many smiths do the 338 Lapua or 338/378wby on the 700's. The 416 rem uses the same action as all the long action 700's do.

    My brother has a 32" straight taper Pacnor barrel to .800" at the muzzle on his 700 in 338/378wby in a Choate Sniper stock. It shoots really, really well using the 300gr SMK at 3000 fps at 65k psi on the Oehler 43.

    You ask around enough and you'll find that it's the biggest anyone will go with that bolt size, many just won't. You find one that has failed because of it's bolt dia or size barrel tennon, you let me know.
    [​IMG] I never have and doubt I ever will. That many smiths just don't stick their necks out and do things to get them into court like that, and Savage wouldn't have a barrel in 338 Lapua because it isn't safe either.

    I'm getting ready to build two rifles based on this case right now, both are using 700 actions too. Good luck and don't just take my word for it either, you do the research and you'll find the same thing I did. [​IMG]

    [ 01-28-2003: Message edited by: Brent ]
     
  4. littletoes

    littletoes Well-Known Member

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    Am curious, the reloading manuals that I have read show the 338 just a little faster than the 340 Weatherby (50 fps). They also show the 338-378 Weatherby much faster than both (200 fps faster than the Lapua). Why are so many saying that the Lapua is comparable to the 338-378? It seems more comparable to the 340?
     
  5. Brent

    Brent Well-Known Member

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    Littletoes,

    You're right, the 338 Lapua Imp is comparable to the 338/378wby because of the major improvements done to it. The 338 Lapua leaves alot for improvement with it's very tapered body and shallow shoulder angle.
     
  6. Guest

    Guest Guest

    [ 07-11-2003: Message edited by: S1 ]
     
  7. AKI

    AKI Member

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    The 338 Lapua case was based on the 416 Rigby necked down and shortened, neck mostly. The Rigby was found too weak at the intended design pressure 470MPa, so the guys at Lapua redesigned the case from scratch. Later the army found the 470MPa too high, so for the CIP a max pressure of 420MPa was selected. Compare this to the 430MPa of magnum cases, 440 of Weatherby and 460MPa of the 300Ultra one can understand why such a large case as the Lapua seems slightly anemic. One should however keep in mind that the case is left as strong as it was designed. If one dares to enter the world ower the max loads in the manuals (max 420MPa), one will find that the potential of the standard case is sunstantial.

    Gentlemen, I have followed this magnificent site for quite some time. I have now got my first reamer, a Lapua Mag Improved (+FL sizer reamer) of my own design and feel an urgent need to tap some of the potential of this site, and, perhaps with some luck, contribute with some minor point some day. AKI
     
  8. Nicholas

    Nicholas Well-Known Member

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    I know someone who is loading 95 grains of H1000 into his Lapua brass while shooting 300 grain Matchkings, talk about hot loads!

    He is getting 2850 fps out of a 26" tube.
     
  9. Dave King

    Dave King Well-Known Member

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    AKI

    Welcome to Long Range Hunting.

    I now have my third 338 Lapua (standard case), I really like this offering and it does very well in holding it's own. Thanks for the bit of design history.

    Thanks and welcome.

    /r

    Dave King
     
  10. Nicholas

    Nicholas Well-Known Member

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    AKI

    What does 470MPa translate to in PSI or CUP??

    I realize that going over listed max loads is pretty dangerous but I am interested to learn more about he 338 Lapua case max capabilities.

    [ 01-30-2003: Message edited by: sr90 ]
     
  11. Brent

    Brent Well-Known Member

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    sr90, 1 lb/sq. in. (psi) = 0.00689 MPa.

    470 is just over 68,000 psi.

    I have a chart, if you want I'll post a pic of it?
     
  12. Brent

    Brent Well-Known Member

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    Steve is shooting his 300's with 95gr RL25 and says it isn't that hot, wouldn't 95gr of RL25 be hotter than 95gr of H1000? I have never used H1000 but isn't even a slower powder?
     
  13. AKI

    AKI Member

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    Thank You Dave. Yes, the plain Lapua is a very good chambering. I have a 31" Border barrel 1:10" twist that I have played with for two seasons along with getting the stock ready and heavy enough. The recoil and torque is surprising at these levels of power, so I can´t say that the package is quite there yet for competition, especially the part that pulls the trigger.

    The reason I started thinking of an Improved was that I have to fullsize the cases too often for my taste. In my HV BR in 6BR I got about 20 stiff reloads out of the cases with no lengthening of the cases before I had to fullsize them. A 30° angle and pretty straight taper evidently does the trick. So I ordered two body reamers from Elliott with 33° angle and absolutly minimum taper. I´m no beliver in very steep shoulder angles, yet.

    The pilot is 22 caliber, so I have plenty of options and the possibility to shorten the case for smaller calibers. My smith is chambering a 31" 1:8,5 twist 308 right now (he isn´t answering any calls, which is a positive sign). But the 338 is, and will be, my main caliber.

    sr90. In a Hodgdon 2000 manual the pressures of various belted magnums are listed at 53000 to 54800 and the 300RUM at max 63100 CUP. CUP´s are, ofcourse, not direktly comparable to "real" measures of pressure. These should roughly correspond to 430/440 and 460MPa. Can´t find the translation factor for PSI to MPa. One pound is .4536kg, and sq inch is .00064516m2. That would make 1Pa=703.7 PSI. But one Pa is 1Newton/m2 which includes an acceleration of 1m/s2 that I can recall how to handle.

    In a brief moment of obstinacy I exceeded the reloading data with N170 and got the Scenars to 3120fps, but the cases popped out of the chamber as with midrange loads. I got the feeling that the rifle breaks before the case. They are apparently almost idiotproof, the rifles _might_ not be, especially if buildt on narrow threaded actions. AKI
     
  14. Nicholas

    Nicholas Well-Known Member

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    Thanks guys


    Brent

    I know the Hodgdon manual says the max load of H1000 in the Lapua is 92 Grains, so going off that info I assume 95 is a pretty big step up. I have talked with Steve about his loads too. I think the Timberwolf would handle extra pressure quite well.
    Does your table show conversions from PSI to CUP?