338 Edge and 338 Lapua AI numbers

Discussion in 'Long Range Hunting & Shooting' started by moses42ak, Sep 29, 2010.

  1. moses42ak

    moses42ak Well-Known Member

    Messages:
    48
    Joined:
    Oct 1, 2009
    I'm considering a long range build and am interested in the 338 Edge or the 338 Lapua AI. This will be a dedicated long range hunting rig for large game. I have but one question:What are the velocity and energy figures at 1,500 yards for each round?

    Thanks for the info.
     

  2. B23

    B23 Well-Known Member

    Messages:
    1,085
    Joined:
    Oct 30, 2008
    Since your question is pretty vague other than the 338Edge and 338 Lapua Improved are the two you're looking at the best answer at this point, is the 338Lap. Imp. is going to have MORE of just about everything than the 338Edge.

    If you pick a specific bullet and barrel length you will get a much more specific answer.
     

  3. moses42ak

    moses42ak Well-Known Member

    Messages:
    48
    Joined:
    Oct 1, 2009
    My apologies. Given a 300 grain SMK with it's BC and real world velocities from the 338 Lapua AI and 338 Edge, what are the energy figures at 1,500 yards. I ask as I am unclear on the velocities of the 338 Lapua AI and have no experience with the 338 Edge either. I'm hoping that someone with said rifle and a ballistics program can post it.

    Another helpful bit of info would be their barrel length.

    Thanks again.
     
  4. Autorotate

    Autorotate Well-Known Member

    Messages:
    503
    Joined:
    Apr 2, 2007
    In considering the whole "system" involved with a cold bore precision at 1500 yards, both calibers have capabilities beyond most hunters/shooters.

    Since you state this will be a dedicated LR hunting rig for large game...these would be some I wish I would've pondered on a while back on my quest-

    1. What range finder do you plan on using that has sufficient beam width divergence to ensure you are ranging the intended target vs. a bush, rock, etc in vicinity of the target at those ranges? At those ranges, given a ISA atmosphere, a range determination error of 5 yards is 6 inches high or low...which could mean the difference between a happy ending to a shot, or the beginning of a long chase.

    2. B23 hit on an important point...there are many variants to the 338 Lapua Improved. In fact dare I say that throat design/barrel may account for 100 fps variance between the different designs of the 338 Lapua Magnum Improved. All things considered equal (throat design, barrel length, quick vs. slow barrel, pressure vs. brass life), a maxed out variant of the 338 Lapua Improved will have more case capacity, and will withstand additional pressure before blowing primer pockets than the 338 Edge, allowing it to outpace the Edge by 35-60 fps.

    3. Ability to make consistent precision ammunition will come into play at these ranges, so brass quality and availability of "easy for you to make precision ammo dies" should come into play as well when deciding between the two.

    4. The initial purchase price advantage of Rem 300 RUM brass vs 338 Lapua brass is just a teaser...don't fool yourself:) You'll be so far down the rabbit hole money wise with a honest 1500 yard cold bore gun, that would be a insignificant factor in making your decision in my opinion. Once you consider brass life...this further evens the field between the two.

    Go to the defensive edge website and review the load data for the 338 Edge.

    I have personal experience with a 338 LMAI does 2920 fps with 104 gr of Retumbo out of a 28" barrel with very good precision.

    Keep in mind most rifles shoot best short of their full velocity potential....that's why you'll see most Edges run at 2820-2850 fps, 'cause that's where they have shown their best precision potential. Same on the 338 LMAI.

    Good luck and remember to keep it fun!
     
    Last edited: Sep 30, 2010
  5. moses42ak

    moses42ak Well-Known Member

    Messages:
    48
    Joined:
    Oct 1, 2009
    Autorotate, thanks for the info. I was not looking for max velcoities but, indeed, real world velocities so as to get maximum accuracy from the weapon and go from there. I see you're in Eagle River. I'm in Peters Creek. What did you end up with in your quest?
     
  6. Autorotate

    Autorotate Well-Known Member

    Messages:
    503
    Joined:
    Apr 2, 2007
    PM sent!
     
  7. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

    Messages:
    2,612
    Joined:
    Mar 12, 2002
    Real world accuracy numbers the better338 lapua ai versions will get you 100-150 fps advantage over the 338-300 ultramag. If you are doing a custom get the 338 lapua AI. I have shot them all.
     
  8. TMR

    TMR Well-Known Member

    Messages:
    555
    Joined:
    Mar 26, 2006
    In my findings, I have either owned or built 338 norma, 338 lapua, 338 Edge, 338 Lapua Imp's, there isn't that much difference between the Edge and the Lapua Imp. I will agree with Tim on throat design plays a bigger part. I found that the 338 Lapua Imp only bested my Edges by about 50-60fps and used another 10 gr of powder to do it. In all fairness, I only had one though and have built 15-20 Edges. With a 30" barrel, the Edges run 2880-2920. 2850 is the norm with the 28" barrels. They have been very consistent and we have shot our personal rifles out to 2100yds using dope at 2920. Cases last 5-7 loadings, which is what my 338 Lapua cases were lasting at the high pressure loadings.

    Again, these are just my personal observations in my builds and playing with all of these over the last few years trying to find the ultimate 338.
     
  9. moses42ak

    moses42ak Well-Known Member

    Messages:
    48
    Joined:
    Oct 1, 2009
    Thanks for the replies and especially Tim for the guidance. I'm going to move forward with a build and will post when finished.
     
  10. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

    Messages:
    2,612
    Joined:
    Mar 12, 2002
    Moses42ak,

    The 338 RUM, 338 Lapua and 338-300 ultramag or edge as you call it are all virtually the same thing with individual barrels making more difference than there is between these three. Considering long range hunting you will not be able to tell any difference between these and neither will the animal. All are equally accurate and either of the three will do anything the others will do duplicating any shot. The better versions of the improved Lapua will step you up 100+ fps over these three and give you a little more gun for longer ranges.

    However, for the range you are talking about you need to go with the 378 wby case and do either a 338-378 wby or one of the improved versions of it. Then you can step up a couple hundred fps and give you more of what you need to get out to 1500+ yards. Less wind drift to deal with and more killing power. The 338-378 wby has set the accuracy and power standard for 40 years that all others have been trying to get to for super long range large big game hunting. It is still the top dawg out there.

    The 338's off the ultramag case are excellent if you have a standard magnum action and want to get into a good 338 inexpensively with just a rebarrel job. But if you are going to spend the money from scratch for a custom there is no sense limiting yourself to the ultramag case when you can blow it away with the 338's based off the 378 wby case and stretch the distance on out there a bit. Or have less wind drift at the lesser ranges of the ultramags.

    I have done most all the big 338's since the 1970's and shot them all side by side and hunted with them. I currently own many big 338's and all the ones commonly talked about on the forum. When I am shooting serious long range I always go with the big 338-378 wby for more power and less wind drift. Bottom line it just gets you further out there better. It costs a little more to shoot. But how much does a guy spend on hunts to put himself in position to take trophy class animals. When you get that one shot why not have the best and eliminate as much of the variables as possible that cause misses. That is where the extra velocity of the big 338-378 pays off. All the choices are equally accurate in a custom rifle, velocity is the key.
     
  11. 3006savage

    3006savage Well-Known Member

    Messages:
    279
    Joined:
    Jul 16, 2008
    I dont have any of the cartridges mentioned so take this post with a grain of salt.

    I would go with the Laupa Improved or the 338-378. This gives a bit more leeway in working up your accuacy load. Max velocity and your accuracy node in many situations are not the same. So if your edge does not shoot well at the max pressures you could find your accuracy loads are at velocities that are less than optimal.

    With the larger cases even your reduced loads would run with a high end edge. Another consideration is that running a Laupa improved or 338-378 at lower pressures and still getting equal velocities could mean much longer brass life and reduce your reloading costs.
     
  12. B23

    B23 Well-Known Member

    Messages:
    1,085
    Joined:
    Oct 30, 2008
    LTLR, how much longer do you believe the barrel needs to be on a 338-378 to see any discernable difference over the better versions of the 338 Lapua Improved?
     
  13. Autorotate

    Autorotate Well-Known Member

    Messages:
    503
    Joined:
    Apr 2, 2007
    I look forward to LTLR response as well.

    I've observed-

    338 Excalibur/4.15 COAL/300 SMK/F215GM/31.25" Brux/ 122-123 gr H50BMG/3070-3085 fps

    338 LMAI/3.9 COAL/300 SMK/F215GM/28" Brux/104gr Retumbo/ 2920 fps

    The Excalibur would fall real close to a 338/378 Wby Imp in case capacity..the Exc fired cases hold approx 138-140 gr of water.

    The LMAI version I shoot holds approx 121 gr of Retumbo, approx 124-125 of water.
     
  14. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

    Messages:
    2,612
    Joined:
    Mar 12, 2002
    B23, My go to 338-378 wby has a 28" Hart barrel and shoots the 300 smk 3060 fps with best accuracy. My go to 338 Lapua Imp had the same barrel and shot just under 3000 fps. On average 80-100 fps slower. From when I developed the 338-300 ultramag in 1998 until 2001 when the 338 RUM came out I did around 100, 338-300 ultras. Best accuracy in those was 2750-2850 fps with a 300 smk and any kind of brass life. During the 90's I worked with several top people around the country trying to develop the best lapua imp. The ones with the shoulder pushed forward and sharper shoulder angles than the standard lapua performed the best. The big 338's just don't gain much velocity per inch so I expect you would see that 80 fps difference from 26"-30" barrels with the lapua imp and the 338-378. So basically you just get down to the fact there is not a lot of difference. But they are a definite step up above the 338-300 ultramag or edge.

    3006savage hit the nail on the head. Bottom line is the 338-378 wby is faster than the others and just as accurate. That gives you more play room. If a guy spends a lot of money for a custom build on say a 338-300 ultramag or edge some call it and the accuracy load is not on the top end of the scale there could be 300 fps difference than if he had built a 338-378 wby. That is a lot of fps. Could get a really fast 338-300 ultra and a really slow 338-378 and only be 100 fps difference between the two. But playing averages it will be about 200 fps difference. If I am doing serious long range work I am not limiting myself 200 fps when it is extremely difficult to judge wind at different velocities across a long canyon shot. The ultramag based stuff can shoot long range. The 338-378 and 338 lapua imp can do it better.