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Designed to replace the 375 Weatherby Magnum, deep penetration and bone smashing power are the calling cards of the 378. Its massive case holds so much powder that Federal designed its super-hot 215 primer to handle the load. Roy Weatherby’s 378 delivers 34 percent more energy at the muzzle than the powerful 375 H&H Magnum. Since 1955, the 378 has become one of the world’s most popular cartridges for the largest of big game animals.
Ballistics
Velocity
Bullet Type
Ballistic Coefficient
@ Muzzle
100 Yards
200 Yards
300 Yards
400 Yards
500 Yards
270 Grain Spire Point
0.380
3180
2921
2677
2445
2225
2017
270 Grain TSX
0.326
3060
2767
2493
2235
1992
1767
300 Grain Round Nose Expanding
0.250
2925
2558
2220
1908
1627
1383
300 Grain Full Metal Jacket
0.275
2925
2591
2280
1991
1725
1489
Energy
Bullet Type
Ballistic Coefficient
@ Muzzle
100 Yards
200 Yards
300 Yards
400 Yards
500 Yards
270 Grain Spire Point
0.380
6062
5115
4295
3583
2968
2438
270 Grain TSX
0.326
5613
4591
3726
2994
2380
1871
300 Grain Round Nose Expanding
0.250
5699
4360
3283
2424
1764
1274
300 Grain Full Metal Jacket
0.275
5699
4470
3461
2640
1983
1476
Trajectory
Bullet Type
Ballistic Coefficient
100 Yards
200 Yards
300 Yards
400 Yards
500 Yards
270 Grain Spire Point
0.380
1.3
0.0
-6.1
-18.1
-37.1
270 Grain TSX
0.326
1.3
0.0
-6.2
-17.9
-36.1
300 Grain Round Nose Expanding
0.250
1.9
0.0
-9.0
-27.8
-60.0
300 Grain Full Metal Jacket
0.275
1.8
0.0
-8.6
-26.1
-55.4
6 reviews for 378 Weatherby Magnum
Rated 5 out of 5
Norbert –
It is the “what ever walks on this planet” cartridge……
Rated 5 out of 5
dråparn –
10+ moose roebuck and beaver have felt the power of the 378. My favorite rifle
Rated 5 out of 5
Tom –
One shot kills when hunting boar is guaranteed. Exit holes like the bottom of a beer stud.
If you want just to “plink” around, 0,5″ groups of 3 shots at 100 yards are not uncommon if you do reloading with Barnes TSX bullets.
Rated 5 out of 5
Jesse –
As a long range caliber it’s hard to beat the 378 weatherby ..
I use this rifle ( many times ) on African plains game out way past 500 yards with a high bc 300 gr bullet …
This is my ultimate hunting experience ever !!
Regards Jesse Wiehahn
Rated 4 out of 5
Nick –
A fine weapon to take down huge bull moose, but not so much the little whitetails my crazy American neighbor shoots with it! I think the bullet field dresses whatever is left of it!
Rated 5 out of 5
Sawman –
When Life is on the line.
378 WEATHERBY MAGNUM
Trust no other.
Norbert –
It is the “what ever walks on this planet” cartridge……
dråparn –
10+ moose roebuck and beaver have felt the power of the 378. My favorite rifle
Tom –
One shot kills when hunting boar is guaranteed. Exit holes like the bottom of a beer stud.
If you want just to “plink” around, 0,5″ groups of 3 shots at 100 yards are not uncommon if you do reloading with Barnes TSX bullets.
Jesse –
As a long range caliber it’s hard to beat the 378 weatherby ..
I use this rifle ( many times ) on African plains game out way past 500 yards with a high bc 300 gr bullet …
This is my ultimate hunting experience ever !!
Regards Jesse Wiehahn
Nick –
A fine weapon to take down huge bull moose, but not so much the little whitetails my crazy American neighbor shoots with it! I think the bullet field dresses whatever is left of it!
Sawman –
When Life is on the line.
378 WEATHERBY MAGNUM
Trust no other.