Hello! I am a new member! I've been looking though the forums and I have learned so much already. I have been shooting forever and have been fixing and improving my guns for several years, now its time to build! I have been researching ballistics and learning about long range shooting and hunting. I have decided to build a .338 Lapua with a Weatherby Mark V action. I am currently hunting for a donor rifle, and I was wondering which rifles actions will work with such a large cartridge?
Which Weatherby Mark V rifles can be used to build a .338 Lapua?
- Thread starter chuxta
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J E Custom
Well-Known Member
Any of the 9 lug Mark V s will work.
You will have to open the bolt face to.590 on all of them (The 378 based cases are .579).
The bolt stop groove will have to be extended a little to get maximum travel from the bolt.
The 378 to 460 extractors work perfectly with little or no work on them.
Also the 378 based mag box and bullet follower work perfectly because it is a flat top follower
and the magazine can be tuned to fit the Lapua case.
The mark Vs are the way to go in my opinion for the Lapua cases.
J E CUSTOM
highridge1
Well-Known Member
Why not just go 338-378 and have more get up and go than the Lapua.Then you don't have to change the bolt face.The 338-378 will out run the Lapua 150-200 fps.
MudRunner2005
Well-Known Member
I agree with the .338-378 Wby Mag comment.....More velocity, and ammo is about the same price, PLUS, no gunsmithing, other than buying a barrel, unless you haven't bought a rifle yet.
If you haven't bought a rifle yet, order a Mark-V AccuMark in .338-378 Wby Mag w/ AccuBrake. You will be pleasantly surprised.
I want a .30-378 Wby Mag bad, for long range whitetail hunting.
If you haven't bought a rifle yet, order a Mark-V AccuMark in .338-378 Wby Mag w/ AccuBrake. You will be pleasantly surprised.
I want a .30-378 Wby Mag bad, for long range whitetail hunting.
That's interesting.. I haven't seen much on the 338-378, the Lapua just made sense to me, with the non belted design and over all performance. Most people I have seen on these forums and others have been quite happy with the Lapua. I know most people on the internet get sub 1/8moa groups -lol- but I have seen many reputable people who are getting great groups with very little to no work on the rifle. I will do some more research on the 338-378. Does this round shoot as flat as the Lapua? Are the cases easy to find? What ranges can i expect from the .338-378? Im not too worried about recoil as this rifle will probably weigh between 10 and 14lbs.
Can you buy these without the accubrake barrel? i dont intend to keep the barrel or the stock. I will put these on ebay or something. If i could find an action only that would be great, hell just the receiver would be nice i can buy a bolt. Cost is an issue but only a small one I am willing to pay for what I want weather or not it takes longer to build i have nothing but time. i wish i could find more information about the .338-378. Am I just hopping on the Lapua train?
MudRunner2005
Well-Known Member
How much for the barrel w/ AccuBrake & stock? 
MudRunner2005
Well-Known Member
I have never been a "go with the grain" type of person...So I always owned oddball calibers. Like my 7mmSTW, .257 Wby Mag, 7mm-08 (back when I bought it, it wasn't very popular), etc...
So, if I were to jump on the big-bore magnum train it would probably be a .375 Cheytac.
I do plan on a Noreen ULR .50 BMG soon, just to have for fun.
So, if I were to jump on the big-bore magnum train it would probably be a .375 Cheytac.
I do plan on a Noreen ULR .50 BMG soon, just to have for fun.
I guess a lot of the reason i want a lapua is because I have never seen one so it is kind of against the grain around here. There aren't many places to shoot 1000 yds much less hunt. I love my .257 roberts it is a custom sporter built on a mauser 98. Most people cock their head to the side when i say .257 and more when i say roberts. haha and whenever i start the build and whatever i decide to buy i will let you know how much for stock and or barrel
between the lapua and the 338-378 aside from recoil what are the pros and cons of each in your experiences?
highridge1
Well-Known Member
With a good brake on a 338 Lapua and a 338-378 you really can't even tell the difference.
I have shot extremely accurate with 338-378's and 300 gr SMK even in a stock accumark rifle .3's the bigger weatherby round is definitely going to shoot flatter and have considerably more energy. I would go min 28 inch barrel plus brake.
I have shot extremely accurate with 338-378's and 300 gr SMK even in a stock accumark rifle .3's the bigger weatherby round is definitely going to shoot flatter and have considerably more energy. I would go min 28 inch barrel plus brake.
highridge1
Well-Known Member
RL25 worked extremely well in my 338-378's I had the best velocity, lowest ES and great accuracy with it. Along with that I use Fed 215 primers.
