I'm searching for some information regarding the .338-378 Weatherby Magnum. Specifically I'd like a ballastics table out to 1000 yards using 200gr, 225gr and 250gr bullets (a 300gr bullet would be nice for reloading reasons). Personal handloads and factory ammo is what I'm looking for in the table. Another thing is the barrel life of the rifle (Weatherby Mark V Accumark), I know the 30-378 has a very short barrel life and am interested to see a comparison. Thanks.

The ballistics table is dependent on a few factors, such as velocity and bullet BC, so all I can suggest is for you to download a program such as "PointBlank", which is a free ballistics program.

Now, to the rifle barrel life question. The 338-378WM will have, on average, a life of around 600 rounds before the throat is eroded enough to affect velocity, this is the thing that you need to keep watch of during use, when the velocity drops with all the components the same, that's throat erosion, how much it drops, I can't tell you. I also can't tell you at what point in the barrels life this will occur. This can only be used if you chrono your ammo every now and then, if you don't, then the only way to tell is when accuracy drops off to a point that it can't be relied upon to hit what you're aiming at.

After this point is reached, it will progress until accuracy starts to fall off in a big way.
If you are using factory ammo for the life of the rifle, and you don't burn it out sighting it in, it may give you a life time of use.

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Weatherby factory ammo, has a 225gr Barnes TSX moving out at 3180. Soooo...

Ballistics Table in Yards

.338-378 Wby 225 gr., .482 B.C. 250 Yard Zero www.hornady.com

Range (yards) Muzzle 100 200 300 400 500 600 700 800 900 1000 Velocity (fps) 3180 2975 2779 2592 2412 2239 2074 1915 1765 1624 1493 Energy (ft.-lb.) 5052 4421 3858 3356 2906 2505 2148 1833 1556 1317 1113 Trajectory (250 yd. zero) -1.5 2.1 1.8 -3.0 -12.9 -28.9 -51.8 -82.7 -123.2 -174.9 -239.8 Come Up in MOA -1.5 -2.0 -0.9 1.0 3.1 5.5 8.2 11.3 14.7 18.6 22.9

Note the velocity at 800 yards. I'm not sure about the TSX min, but a Nosler Accubond has a min impact velocity of 1800 fps.

One more

Ballistics Table in Yards

.338-378 Wby, Nosler Partition 250 gr., .473 B.C. , 250yd Zero www.hornady.com

Range (yards) Muzzle 100 200 300 400 500 600 700 800 900 1000 Velocity (fps) 3060 2857 2663 2476 2298 2127 1963 1808 1661 1524 1400 Energy (ft.-lb.) 5198 4530 3935 3404 2931 2511 2139 1814 1531 1290 1087 Trajectory (250 yd. zero) -1.5 2.4 2.0 -3.3 -14.2 -31.7 -57.0 -91.3 -136.2 -193.8 -266.6 Come Up in MOA -1.5 -2.3 -0.9 1.0 3.4 6.1 9.1 12.4 16.3 20.6 25.5

You can look at factory Weatherby ammo and ballistics here http://www.weatherby.com/product/ammunition/ballistic

And Hornady has a free, online ballistics calculator here http://www.hornady.com/ballistics/ba...calculator.php

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Volatile & Unstable

If you're going to spend that kind of money, get the true king of the 338's: the 8.59 Titan from Lazzeroni. It shoots a 225 at 3300 fps or a 250 as fast as the 338-378 shoots a 225.

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Thanks for the information. Only 600 round barrel life? **** thats extremely low, about 6 years or so with the amount I'd like to shoot it.

Performance definately has a price. Personally I think your best bet is either the 300 or 338 RUM. Not too far off the Weatherby's based on the 378 case, ammo is less expensive (or brass if you load later) and you can get rifles based on the great Remington action.

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I'm intrigued with the Lazzeroni 8.59 Titan 225gr 338-378 for a Weatherby Mark V Deluxe I'm looking to buy. I noticed the ballistics chart on the Lazzeroni site didn't list ballistic coefficients. Any suggestions for I how I would calculate these? It's info I'd need for having custom elevations and windage BCD dials added to a Leupold scope. The chart says to contact the bullet manufacturer for the B/C. Who should I be contacting specifically?

Here's the chart they've got posted:





Thanks.


John

8.59 Titan
185gr BC is 0.480
225gr BC is 0.510
250gr BC is 0.540

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Diawhatever,
I'd opt a plain jane turret. MOA is your friend. Switch up loads, just shoot to find out the adjustments and record them.

Lazzeroni supposedly uses questionable tact in attaining ballistic info, and I just flat wouldn't trust factory printout 'til I shot to find out. I'd rather dump my change on something else...but fat wallets can sometimes rake in stuff that works.

You guys quoting off factory websites and claiming them as fact have a lot to learn. I'm not trying to be a dick, but every rifle is different, some may be faster than the published velocity, the vast majority are slower.

Additionally, there is more than one BC for bullets, based on the speed, so a hard BC is worthless if you don't know the velocity it was launched at.

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