338 Water Capacity

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Casscade, Aug 6, 2009.

  1. Casscade

    Casscade Well-Known Member

    Oct 31, 2005
    Anyone have the water capacities for the 338lapua,338rum,340wby, and for the 338 lazz titan. Thanks.
  2. steve smith

    steve smith Well-Known Member

    Jul 4, 2001
    Quickload list them as follows.

    .338-378 Weath. Mag. 137.5 gr H20
    .338 Titan 123.5 gr
    .338 Rem Ultra Mag 110 gr
    .338 Lapua Mag 108 gr
    .338 Norma Mag. 106 gr
    .340 Weath. Mag. 100 gr

  3. LouBoyd

    LouBoyd Well-Known Member

    Oct 15, 2007
    From the Quickload database (grains H20)
    338 Spectre 28.8
    338-7BR 43
    338 Federal 57.5
    338 Win nag 86
    340 Wby mag 100
    338 Norma mag 106
    338 Lapua mag 108
    338 Rum 110
    338 Edge 113
    Lazz Titan 123.5
    338-378 Wby 137

    Don't just compare cases by capacity. The differece between case length and overall length (or magazine or action length) will affect seating depth which changes the combustion chamber capacity. The 338 Lapua magnum is a relativley short fat case which gives it more usable capacity than it's slightly larger neighbors when used with long low drag bullets. The 338 Win Mag can also be seated out further than SAAMI spec when used in a "long magnum" magazine. Most of the other magnums are pretty crowded in "long magnum" magazines. Compare complete cartidges at workable seating depths in the action you choose to use. Somtimes the smaller capacity cartridge gives higher performance.
    Last edited: Aug 6, 2009
  4. Casscade

    Casscade Well-Known Member

    Oct 31, 2005
    Is that with lapua brand brass, and btw whats a 300 rum. Thanks again guys.
  5. AJ Peacock

    AJ Peacock Well-Known Member

    Oct 7, 2005

  6. Autorotate

    Autorotate Well-Known Member

    Apr 2, 2007
    338-378 Wby cases actually measured up around 126-127 grains for me.
  7. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

    Mar 12, 2002
    I can give you dozens of loads with the 340 wby, 338 lapua, 338 and 338-300 ultramags all out of 28" barrels. Max loads are all within about a hundred fps with all of these except the lapua. Overall the lapua data is the fastest of these and will get about 150 fps spread over the 340 wby. Some may be faster or slower barrels but I am talking averaging data over many rifles tested. From my experience in a hunting situation you will not notice much difference with any of them. I guess water capacity will put you in the ballpark but like mentioned above different case designs may perform better or worse. The 338-378 wby shown has tremendous water capacity but is only 150 fps faster than the lapua. So from slowest to fastest of all of those your looking at about 300 fps. If anyone wants any of that data I will be glad to look it up and post it here.

    I have catalogs of data on these 338's mentioned. I love to shoot all of mine but most of my hunting goes to the low side 340 wby or the high side 338-378 wby. In a hunting situation I notice no difference between the 340 wby and the ultramags so I go with less powder, recoil and muzzle blast. When I want a big gun I pick up my 338-378 wby which seperates itself from the rest of the pack. Honestly, if I had an elk out there at a thousand yards give me any of them because they are all very capable rifles. With the extra velocity of the 338-378 it will give you a little edge in the wind which is the hardest thing to judge. I tried since the 70's trying to find the highest velocity 338. Bottom line there is just not much seperation between them with max loads. So just get any of them, accurize it and you are good for long range big game.
    Last edited: Aug 8, 2009