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Load data for .378 Weath. Mag. + .375 | 300gr | Sierra SBT GameKing

Recommended Powder(s): ADI AR 2209, Alliant Reloder-19, Norma MRP, Rottweil R 905, Somchem S385

.378 Weath. Mag. + .375 | 300gr | Sierra SBT GameKing

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.375 | 300gr | Sierra SBT GameKing
Manufacturer SKU:
3000
Bullet Weight:
300gr | 19.4g
Bullet Diameter:
0.375" | 9.52mm
Bullet Length:
1.378" | 35.0mm
Caliber:
.378 Weath. Mag. load data
Case Length (l3):
2.913" | 74.0mm
Cartridge Length (C.O.L.):
3.600" | 91.4mm
Seated Depth:
0.691" | 17.5mm
Shank Seated Depth:
0.521" | 13.2mm
Case Capacity:
137.0 Grains of Water | 8.90 cm³
Primer Size:
Large Rifle Magnum (LRM)
Max. allowed Pressure:
63817 psi | 4400 bar
LID:
LID_B5958_C577
Last updated:
2025-01-01
Recommended Twist Rate:
1:18 - 1:15

Load data for 144 loads in caliber .378 Weath. Mag. with .375 | 300gr | Sierra SBT GameKing bullet and 72 powders such as ADI AR 2209, Alliant Reloder-19, Norma MRP, Rottweil R 905, Somchem S385. The key underlying parameters are shown in the table above.

  • Important Notice: DO NOT go below Minimum Charge or above Maximum Charge unless there are reasons. Since xxlreloading.com has no control over the equipment and components used by the customer and the data used in connection with the website, any responsibility and liability for the results achieved is rejected. Also see our Terms of Service

    Questions regarding the load data: Please read the information in the next tab "Explanations".

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  • .

    Use the Personalized Load Calculator to customize loads to your own specific requirements. Find more details in the help section.

    Our default view only displays powders/loads that fulfill certain criteria: Max pressure of a load <=90% of Max. Standardized Pressure. Fill Rate (Min FR): >80% and <100% for rife loads,  >60% and <100% for pistol loads. Min. Propellant Combustion (Min z): >90% for rifle loads , >80% for pistol/revolver loads. Relax these criteria at your own risk to potentially get more powders shown in the load tables.

Click on the desired row in the tables below to add a specific load / powder to your Diary and manage there.

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2208
<<locked>>
83%
57406
90%
**74
100%
ADI AR 2209 👍
<<locked>>
93%
57058
89%
**76
99%
ADI AR 2213
<<locked>>
97%
57116
89%
**05
99%
ADI AR 2217
<<locked>>
97%
42395
66%
**46
96%
ADI AR 2225
<<locked>>
97%
37608
59%
**10
98%
Accurate 2700
<<locked>>
84%
56971
89%
**48
100%
Accurate 3100
<<locked>>
97%
57000
89%
**17
100%
Accurate 4350
<<locked>>
88%
57246
90%
**33
100%
Accurate MAGPRO
<<locked>>
97%
56942
89%
**28
97%
Alliant Reloder-16
<<locked>>
89%
57363
90%
**69
100%
Alliant Reloder-17
<<locked>>
84%
56840
89%
**69
100%
Alliant Reloder-19 👍
<<locked>>
94%
57290
90%
**72
100%
Alliant Reloder-22
<<locked>>
97%
57246
90%
**12
100%
Alliant Reloder-23
<<locked>>
97%
54563
86%
**33
100%
Alliant Reloder-25
<<locked>>
97%
47413
74%
**84
100%
Alliant Reloder-26
<<locked>>
94%
56884
89%
**44
100%
Hodgdon H1000
<<locked>>
97%
42395
66%
**46
96%
Hodgdon H414
<<locked>>
84%
57203
90%
**56
100%
Hodgdon H4350
<<locked>>
91%
57130
90%
**10
100%
Hodgdon H4831
<<locked>>
97%
53577
84%
**00
98%
Hodgdon H4831 SC
<<locked>>
95%
57188
90%
**49
98%
Hodgdon Hybrid 100V
<<locked>>
91%
57348
90%
**94
100%
Hodgdon LVR
<<locked>>
86%
57217
90%
**33
100%
Hodgdon Retumbo
<<locked>>
97%
37608
59%
**10
98%
Hodgdon Superperformance
<<locked>>
87%
57174
90%
**89
100%
Hodgdon VARGET
<<locked>>
83%
57406
90%
**74
100%
IMR 4064
<<locked>>
83%
56942
89%
**57
100%
IMR 4166 Enduron
<<locked>>
84%
57377
90%
**74
100%
IMR 4350
<<locked>>
90%
57319
90%
**07
100%
IMR 4451 Enduron
<<locked>>
85%
57087
89%
**94
100%
IMR 4831
<<locked>>
93%
57246
90%
**17
100%
IMR 4955 Enduron
<<locked>>
96%
57116
90%
**20
98%
IMR 7828 SSC
<<locked>>
95%
56840
89%
**18
99%
[IMR 8133 Enduron]*
<<locked>>
97%
33591
53%
**11
92%
Lovex S065
<<locked>>
87%
56985
89%
**80
100%
Lovex S070
<<locked>>
88%
57145
90%
**10
100%
Lovex S071
<<locked>>
97%
48443
76%
**92
100%
Norma 204
<<locked>>
89%
57290
90%
**49
99%
Norma 217
<<locked>>
97%
33576
53%
**34
95%
Norma MRP 👍
<<locked>>
95%
56971
89%
**28
100%
Norma URP
<<locked>>
88%
57072
89%
**36
100%
Ramshot Hunter
<<locked>>
89%
57159
90%
**59
100%
Ramshot Magnum
<<locked>>
97%
55956
88%
**82
100%
ReloadSwiss RS 14
<<locked>>
97%
36245
57%
**80
100%
ReloadSwiss RS 60
<<locked>>
86%
57072
89%
**89
100%
ReloadSwiss RS 62
<<locked>>
88%
56956
89%
**56
100%
ReloadSwiss RS 70
<<locked>>
89%
57087
89%
**05
100%
ReloadSwiss RS 76
<<locked>>
97%
46050
72%
**23
100%
[ReloadSwiss RS 80]*
<<locked>>
97%
41466
65%
**02
94%
Rottweil R 903
<<locked>>
84%
57406
90%
**74
100%
Rottweil R 904
<<locked>>
92%
56927
89%
**17
99%
Rottweil R 905 👍
<<locked>>
94%
57392
90%
**66
100%
Rottweil R 907
<<locked>>
86%
57130
90%
**90
100%
SNPE Vectan Tubal 5000
<<locked>>
83%
56855
89%
**46
100%
SNPE Vectan Tubal 7000
<<locked>>
87%
57261
90%
**48
100%
Shooters World Long Rifle
<<locked>>
87%
56985
89%
**80
100%
Somchem S355
<<locked>>
84%
56985
89%
**71
100%
Somchem S361
<<locked>>
92%
57290
90%
**00
98%
Somchem S365
<<locked>>
90%
57072
89%
**33
100%
Somchem S385 👍
<<locked>>
94%
57000
89%
**36
100%
Vihtavuori N135
<<locked>>
85%
57130
90%
**79
100%
Vihtavuori N150
<<locked>>
89%
57246
90%
**31
100%
Vihtavuori N160
<<locked>>
86%
57348
90%
**03
100%
Vihtavuori N165
<<locked>>
97%
53548
84%
**71
99%
Vihtavuori N550
<<locked>>
86%
57246
90%
**36
100%
Vihtavuori N555
<<locked>>
95%
57072
89%
**62
100%
Vihtavuori N560
<<locked>>
97%
57276
90%
**38
99%
Vihtavuori N565
<<locked>>
97%
49342
77%
**90
97%
[Vihtavuori N568]*
<<locked>>
97%
43047
67%
**25
94%
Winchester 6.5 StaBALL
<<locked>>
88%
57276
90%
**74
100%
Winchester 760
<<locked>>
84%
57203
90%
**56
100%
Winchester StaBALL HD
<<locked>>
97%
51285
80%
**08
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2208
<<locked>>
81%
53954
85%
**21
100%
ADI AR 2209
<<locked>>
81%
38087
60%
**34
96%
[ADI AR 2213]*
<<locked>>
81%
33982
53%
**59
92%
[ADI AR 2217]*
<<locked>>
88%
31314
49%
**83
90%
[ADI AR 2225]*
<<locked>>
85%
26049
41%
**69
90%
Accurate 2700
<<locked>>
81%
52156
82%
**72
99%
Accurate 3100
<<locked>>
81%
33837
53%
**16
97%
Accurate 4350
<<locked>>
81%
45585
71%
**56
100%
[Accurate MAGPRO]*
<<locked>>
83%
34447
54%
**95
90%
Alliant Reloder-16
<<locked>>
81%
43729
69%
**59
100%
Alliant Reloder-17
<<locked>>
81%
50430
79%
**74
100%
Alliant Reloder-19
<<locked>>
81%
38043
60%
**34
96%
[Alliant Reloder-22]*
<<locked>>
81%
33808
53%
**75
94%
Alliant Reloder-23
<<locked>>
81%
32474
51%
**43
99%
Alliant Reloder-25
<<locked>>
81%
28398
44%
**54
95%
Alliant Reloder-26
<<locked>>
81%
35215
55%
**64
99%
[Hodgdon H1000]*
<<locked>>
88%
31314
49%
**83
90%
Hodgdon H414
<<locked>>
81%
51300
80%
**64
100%
Hodgdon H4350
<<locked>>
81%
41727
65%
**57
98%
[Hodgdon H4831]*
<<locked>>
81%
32068
50%
**70
90%
[Hodgdon H4831 SC]*
<<locked>>
81%
35607
56%
**59
92%
Hodgdon Hybrid 100V
<<locked>>
81%
41220
65%
**51
100%
Hodgdon LVR
<<locked>>
81%
48138
75%
**95
100%
[Hodgdon Retumbo]*
<<locked>>
85%
26049
41%
**69
90%
Hodgdon Superperformance
<<locked>>
81%
46543
73%
**21
99%
Hodgdon VARGET
<<locked>>
81%
53534
84%
**18
100%
IMR 4064
<<locked>>
81%
52968
83%
**98
100%
IMR 4166 Enduron
<<locked>>
81%
51561
81%
**85
100%
IMR 4350
<<locked>>
81%
43976
69%
**97
98%
IMR 4451 Enduron
<<locked>>
81%
50053
78%
**82
99%
IMR 4831
<<locked>>
81%
39305
62%
**25
100%
[IMR 4955 Enduron]*
<<locked>>
81%
35984
56%
**29
93%
[IMR 7828 SSC]*
<<locked>>
81%
34577
54%
**92
92%
[IMR 8133 Enduron]*
<<locked>>
93%
30023
47%
**10
90%
Lovex S065
<<locked>>
81%
47413
74%
**33
100%
Lovex S070
<<locked>>
81%
45759
72%
**23
99%
Lovex S071
<<locked>>
81%
28979
45%
**92
95%
Norma 204
<<locked>>
81%
43932
69%
**30
97%
[Norma 217]*
<<locked>>
89%
26092
41%
**15
90%
Norma MRP
<<locked>>
81%
35230
55%
**38
96%
Norma URP
<<locked>>
81%
44817
70%
**43
100%
Ramshot Hunter
<<locked>>
81%
43526
68%
**39
99%
[Ramshot Magnum]*
<<locked>>
81%
31038
49%
**03
94%
ReloadSwiss RS 14
<<locked>>
93%
34214
54%
**47
100%
ReloadSwiss RS 60
<<locked>>
81%
48443
76%
**64
100%
ReloadSwiss RS 62
<<locked>>
81%
45440
71%
**75
100%
ReloadSwiss RS 70
<<locked>>
81%
43540
68%
**89
100%
[ReloadSwiss RS 76]*
<<locked>>
81%
26614
42%
**18
90%
[ReloadSwiss RS 80]*
<<locked>>
91%
33475
52%
**18
90%
Rottweil R 903
<<locked>>
81%
52808
83%
**15
100%
Rottweil R 904
<<locked>>
81%
39552
62%
**18
95%
Rottweil R 905
<<locked>>
81%
37231
58%
**11
96%
Rottweil R 907
<<locked>>
81%
48689
76%
**59
99%
SNPE Vectan Tubal 5000
<<locked>>
81%
52837
83%
**00
100%
SNPE Vectan Tubal 7000
<<locked>>
81%
46456
73%
**87
99%
Shooters World Long Rifle
<<locked>>
81%
47413
74%
**33
100%
Somchem S355
<<locked>>
81%
52547
82%
**08
100%
[Somchem S361]*
<<locked>>
81%
40045
63%
**05
94%
Somchem S365
<<locked>>
81%
41640
65%
**07
100%
Somchem S385
<<locked>>
81%
37927
59%
**05
97%
Vihtavuori N135
<<locked>>
81%
51271
80%
**00
100%
Vihtavuori N150
<<locked>>
81%
45194
71%
**61
100%
Vihtavuori N160
<<locked>>
81%
48240
76%
**69
100%
[Vihtavuori N165]*
<<locked>>
81%
31952
50%
**64
94%
Vihtavuori N550
<<locked>>
81%
48602
76%
**08
100%
Vihtavuori N555
<<locked>>
81%
36390
57%
**11
99%
[Vihtavuori N560]*
<<locked>>
81%
33852
53%
**79
91%
[Vihtavuori N565]*
<<locked>>
83%
30298
47%
**90
90%
[Vihtavuori N568]*
<<locked>>
91%
34795
55%
**34
90%
Winchester 6.5 StaBALL
<<locked>>
81%
45324
71%
**07
100%
Winchester 760
<<locked>>
81%
51300
80%
**64
100%
Winchester StaBALL HD
<<locked>>
81%
27528
43%
**52
100%

Start Load - Barrel Length: 23.60''

Any powder missing? Then click here.

FR ... fill rate of the cartridge in percent

MaxP ... max. pressure of load in psi or bar

% ... max. pressure of load in percent of the maximum allowed pressure for this caliber 

V(0) ... muzzle velocity in feet per second (fps) or  meters per second (m/s)

z ... powder burnt in percent

[...] *... not dangerous but load has suboptimal powder burnt with possible characteristics such as extensive muzzle flash or inaccurate loads.

[...] ²... fill rate low - you might want to consider using a filler to ensure proper ignition.

[...] ᴾ... possible press load - work up slowly to this load while watching for signs of excessive pressure.

👍  ... recommended powder/load for this caliber and bullet combination based on its ballistic performance.

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