338-378 Weatherby Ammo
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Weatherby Select Plus 338-378 Weatherby Mag 225 grain Barnes TTSX Rifle Ammo, 20/Box - B333225TTSX
Brand:
Weatherby
Bullet Type:
Barnes Tipped TSX Lead Free
Caliber:
.338-378 WBY MAG
Grains:
225 grain
Rounds:
20
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Weatherby Select Plus .338-378 Weatherby Magnum 262 gr SCHP 20rds
Brand:
Weatherby
Caliber:
.338-378 WBY MAG
Rounds:
20
(8)
Weatherby Select Plus 338-378 Weatherby Mag 250 grain Partition Rifle Ammo, 20/Box - N333250PT
Brand:
Weatherby
Bullet Type:
Nosler Partition
Caliber:
.338-378 WBY MAG
Grains:
250 grain
Rounds:
20
(0)
Weatherby Barnes 225 gr Triple-Shock X .338-378 Weatherby Mag Ammo, 20/box - B333225TSX
Brand:
Weatherby
Bullet Type:
Barnes Triple Shock X
Caliber:
.338-378 WBY MAG
Grains:
225 grain
Rounds:
20
Marketplace Insights
★ 4.7/5
based on 10 customer reviews across 12 variants from 21 retailers
Highly praised for exceptional accuracy and performance on big game, though limited ammunition availability and one quality control issue dampen otherwise outstanding customer satisfaction.
What customers like
Accuracy & Performance80%
Superior quality, aesthetically pleasing, extremely accurate at long distances
Ammo Scarcity Issue50%
just wish the ammunition was more attainable here in Canada
Big Game Hunting50%
all 3 stop right there, same thing on black bear
Value & Quality30%
Definitely worth the price
Common concerns
Shipping Condition & QA10%
marks, dents and scratches in the wood. The scope's condition wasn't impressive
Frequently Asked Questions
338-378 Weatherby Ammo
What is the difference between 338 Lapua and 338 378 WBY?
.338 Lapua uses a non-belted case with 114.2 gr water capacity, while .338-378 Weatherby is belted with 125 gr capacity. Weatherby delivers roughly 150-200 fps more velocity but burns barrels faster. Lapua offers longer case life and easier worldwide brass availability.
What is the ballistics of a 338 378 Weatherby?
The .338-378 Weatherby fires 200-grain bullets at approximately 3300 fps from a 26-inch barrel, with 250-grain bullets around 2900 fps. Energy figures exceed 4,800 ft-lbs, with some loads surpassing 5,000 ft-lbs. It outpaces the .338 Lapua Magnum by roughly 100–200 fps, making it one of the most powerful .338 cartridges available.
What is 338-378 Weatherby?
The .338-378 Weatherby Magnum is a cartridge introduced in 1998, formed by necking down the .378 Weatherby case to accept .338-caliber bullets. It produces higher velocities than the .338 Lapua Magnum, making it effective for long-range hunting of large game. Twelve variants are currently produced.
What is the most powerful 338 cartridge?
The most powerful production .338 cartridge is contested. The .338-378 Weatherby Magnum and .338 Remington Ultra Mag both rank among the most powerful factory offerings, pushing 250-grain bullets near 2900 fps with over 5000 ft-lbs of energy. Custom wildcats like the .338 Allen Magnum exceed both.