Below is a Mark v action custom in 338-378 Weatherby. Rifle is a beast, shoots the Berger 300 OTMs just under 3,000 FPS not loaded hot. Started with a 32 inch Lilja however it was unmanageable to carry so chopped to 28 inches plus the break. Standard deviation is great around 25 FPS so rifle is very repeatable. Norma brass is excellent to work with. Rifle is sub MOA consistently at 500. Great caliber.
338-378 WBY Mag vs 338 Edge
- Thread starter Iron Worker
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I've never had an edge. I picked up a barely used .338-.378 Accumark for a great price and am thrilled with it. Elk tumble at the sound. It easily holds 1/2 - 3/4" groups with factory ammo. It's hard to ask for more.
bigbulldoza
Member
Brush4646
Well-Known Member
I
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ofbandg
Well-Known Member
One of my long time hunting buddies had a .340 wby restocked and converted to a .338-378 when the concept first became popular, maybe 30 years ago. He used it exclusively on our northern moose and grizzly hunts. At that time there was no factory brass and very little loading data so it took a while to do load development. He settled on 250 grain Noslers doing about 3000 fps out of a 26 inch barrel. (no muzzle brake) That rifle accounted for many large moose at long range and a considerable number of grizzly, including one that was rapidly approaching me at a time when I couldn't get at my rifle. It is a very effective hunting weapon. On the downside, you don't carry it far unless you are strong and in great shape. We hunt the swamp and muskeg country between the Alaska Highway and the Yukon border - and we do it on mud rigged four wheelers so hauling heavy and awkward rifles isn't a problem. These rifles aren't handy so fast shots and bringing them into battery is a process. Then there is recoil. When my friend got into his '70's he retired this rifle and now uses a 300 ultramag. You can suffer serious whiplash just sighting in his old rifle. As for the scope bases and rings, once he got a set-up he liked he epoxied the bases down and the rings to the bases and has had no problems. I had been doing that since the '70's when my benchrest buddies showed me how. A little bit of heat from a finely adjusted torch and they come apart if necessary but it removes one of the variables on the way to consistency.
Iceking02
Active Member
Hey OP,
I have a 338-378 Wby converted to .338 Edge. I purchased a Dan Lilja barrel at 30". It was chambered and coated by Matt Cockrell at the recommendation of Dan Lilja himself. It is topped with the Near Alphamount scope base/ring combo. For glass I have the Swaro X5, 5-25x56. I bedded the receiver and mounts myself. It has and will shoot 1-hole groups at 300yds and sub-MOA at 1000yds (3-shots) if you can hold it steady and if your loading is up to the 2nd-degree black belt level. I know that I can still do better but this rifle fulfills almost all of my needs excepting for barrel/brake length. BTW, my velocities are not as high as others with the 300 OTMs (2832fps) but the ES is single digit on most every 5 and 10-shot string.
I was inspired for this build after shooting a similar conversion by AUTOROTATE. These are pretty darn cool.
Bob
I have a 338-378 Wby converted to .338 Edge. I purchased a Dan Lilja barrel at 30". It was chambered and coated by Matt Cockrell at the recommendation of Dan Lilja himself. It is topped with the Near Alphamount scope base/ring combo. For glass I have the Swaro X5, 5-25x56. I bedded the receiver and mounts myself. It has and will shoot 1-hole groups at 300yds and sub-MOA at 1000yds (3-shots) if you can hold it steady and if your loading is up to the 2nd-degree black belt level. I know that I can still do better but this rifle fulfills almost all of my needs excepting for barrel/brake length. BTW, my velocities are not as high as others with the 300 OTMs (2832fps) but the ES is single digit on most every 5 and 10-shot string.
I was inspired for this build after shooting a similar conversion by AUTOROTATE. These are pretty darn cool.
Bob
Michael O'Connor
Well-Known Member
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- Dec 7, 2017
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I would go with a 338 Lapua Imp. ( AKA, 338 Allen Express) Shoots the 300 gr. Berger to
3000fps with a lot less powder than the
338/378. Quit giving all your money to these powder manufacturers, for more recoil and less barrel life .
3000fps with a lot less powder than the
338/378. Quit giving all your money to these powder manufacturers, for more recoil and less barrel life .
Deadeye9999
Member
For what it's worth. I have a custom 338/378 with a 30" McGowen Tube. 20moa NEAR rail with Warne steel rings. Shooting 300 vlds all day long. No issues what so ever. But the best products you can afford.
Wallie
Well-Known Member
This is what I came up as well, when I tackled this question for myself.
Reading through this thread I realize I got there for slightly different reasons though.
Probably fairly subjective because I know other people bias their decision making criteria differently... but I prefer rock solid brass (figuratively speaking of course!) to be the cornerstone of my builds. I don't care as much about squeezing every last FPS out as long as I can deliver my projectile of choice with sufficient energy (or is some cases remaining velocity to assure bullet expansion) to my personal maximum effective range.
This has been a few years back, so it's entirely possible superior brass is available now, but that was why I ruled out the Edge, and gave the slight advantage to Lapua over the extra HP the huge Wby offered. I dislike needing second degree black belt reloading skills to get sub 1/4 moa with single digit SD's (again, just my personal benchmark).
This is why I built a 260 instead of creedmore (when hornady brass was the only game in town for the CM).
Michael O'Connor
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I like how you think, and I have a 6.5 CM in an AR-10. I had a model 7 in 260 and sold it. If I bought another 260, I would get a SLR in a Tikka. It will take the longer bullets with an intermediate magazine length without crowding powder space. 30° shoulder with a long neck that cycles well and improves barrel life.
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How would it be if he just blew it out to a .375,then it basically a 378 Wby,seems like they push a 300 gr or lighter?Dont know have no experience with?Wouldnt that good LR Sorry went back and reread,thought he already had 338.
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I do have a 338-378 ,just thinking ahead to caliber of next bbl .Haven't been able to develop a load for this yet because of tech problems that I posted in my other threads.
I used probably same rail but I think you could re drill hole and I jb weld mine to rifle on my 340,been on there for years.And you might use a three ring set up?My NM has oversized screws for the rail,dont remember size,but slight larger than standard
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dgarrett
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- Dec 2, 2012
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- 520
I bought the Near 20moa rail and 6 screw rings for my current 30-378....Scope was set to high for me to get my regular cheek weld... I can't shot prone due to spine problems... Since for ever I have always kept my scope bell as low to the barrel as I could.... Finally just to get the thing up and running went to local store and just put the Leupold duel dovetails on it.... This is with a sightron IIII 6-24x50mm scope. So not super light.....Scope or nothing has moved since mounting it some 2 years ago with over 100 rounds down the pipe...Dave. .
