need help making up my mind

huntinfool18

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guys im having trouble making up my mind. i have all the componts to build this rifle. but i cant decide between a 338-378wby or 338 lapua impoved. i have dies and brass for both just cant make up my mind. is one gonna be more accurate the the other?
 

liltank

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Brass will be much better for the Lapua. They will be just about ballistically the same. I think the Weatherby will out run it a little, but not by much. I would have to say I like the Lapua. Shoot one pretty regularly and in one word, "Awesome!" In my opinion you really don't need much more than what it can provide. You AI that sucker and you are on your way to very long shots with devastating effects. When you compare loading costs you are looking about the same initially, but probably get more life out of the Lapua brass. Have fun! The Weatherby is going to be equally as devastating at distance. SOOOO... that is my humble opinion.

Tank
 

J E Custom

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Brass will be much better for the Lapua. They will be just about ballistically the same. I think the Weatherby will out run it a little, but not by much. I would have to say I like the Lapua. Shoot one pretty regularly and in one word, "Awesome!" In my opinion you really don't need much more than what it can provide. You AI that sucker and you are on your way to very long shots with devastating effects. When you compare loading costs you are looking about the same initially, but probably get more life out of the Lapua brass. Have fun! The Weatherby is going to be equally as devastating at distance. SOOOO... that is my humble opinion.

Tank

+1
I am a big Weatherby fan but if you have the brass and the dies's for eather one I would have to recomend the Lapua for ease of loading and brass life.

As to the accuracy, they both can be made very accurate so it's just a matter of which one.

Now That the Weatherby Brass has gone off the charts there is no advantage in price and
the quality of the Lapua brass it better than Norma (Who makes Weatherby brass) .

If you have an action that will handel the 378 case head then you have one big enough
for the Lapua.

J E CUSTOM
 

RockyMtnMT

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All things considered, the Lapua brass out weighs the little extra speed of the Weatherby.

my .02

Steve
 

trueblue

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LAPUA AI
Are you building a single shot for a COAL of 3.90+, if not, what mag system are you using?
 

Autorotate

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HF18

I agree with all the remarks above regarding the high quality/uniformity and toughness of the Lapua brass.

The MV difference between the two will depend on barrel length, the desired bullet weights you'll be shooting, powders you will be shooting, and exactly how much improvement your chamber made to the Lapua case, and throat design of the reamers that will be used to chamber your rifle.

So the questions I'd ask are:

1. Barrel length
2. Desired bullet weights
3. COAL/bullet used on the dummy round used to design the reamer
4. Desired powders

While the performance of both chambers will be close, there is no substitute for case capacity when comparing two cartridges at equal pressures.

So it again depends on your goals for this rifle, and specifically the factors listed above.

There are Wby Improved designs that will put that case over 135+ grains of capacity after firing. You will have to run a Lapua Improved very hard pressure wise to make up for 10-12 grains of case capacity (depending on the amount of improvement done on the Lapua case) that a Wby Improved would offer.

If your barrel is very long, you favor the heaviest of bullet weights, the Lapua had a short throat, the Wby had a longer throat, and you don't mind shooting H50BMG, slower powders, the larger case capacity of the Wby will out perform the Lapua....at equal pressures.

But....at a cost of case life. Some will run the Lapua Improved at higher pressures and achieve the same velocities as the Wby, because the brass is so tough it allows multiple high pressure loadings over and over again.

Good luck.
 
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Autorotate

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HF18

The downrange ballistic performance of the two will be nearly identical, and after you run the numbers on any of the high BC 338 bullets offerred today, or about to be released....you'll quickly surmise that the capabilities of the shooter to both determine wind corrections, shoot straight, and your laser will be tested before these calibers run out of range. gun)

It's up to you to decide what the exta fps is worth seeing on your chrono :cool:

Good luck!
 

huntinfool18

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thanks for the input guys. i will be using a weatherby mark 5 action that it a 338-378 right now. barrel is a broughton 9.3twist and will be 27" + break. bullets i would like to use are the 300gr matchkings and wildcats. the reamer i have is throat the is for 250gr matchking
 

Long Time Long Ranger

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I have shot both quite a bit but I have sold my lapua improved. Still have seven 338-378 wby's. The main difference is the shorter lapua case allowing bullets seated closer to the lands to feed through the magazine. The long 378 case with a 300 matchking seated out to the lands is a single shot. The wby is faster. With the 250 matchking it will not make as much of a difference. I can tell you from experience with both you will be satisfied whichever choice you make. One you may want to consider is the 338-416 Rigby improved. It is just a tad faster and brass is less expensive however the original fireforming process is more difficult. Hornady brass for the 416 is much more reasonable than the other two and this one is about the fastest off the action you have. To get faster you would have to go to the chey-tac case and a huge/heavy custom action/rifle.
 
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