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Load data for .378 Weath. Mag. + .375 | 300gr | Speer TBBC

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

.378 Weath. Mag. + .375 | 300gr | Speer TBBC

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.375 | 300gr | Speer TBBC
Manufacturer SKU:
1780
Bullet Weight:
300gr | 19.4g
Bullet Diameter:
0.375" | 9.52mm
Bullet Length:
1.390" | 35.3mm
Caliber:
.378 Weath. Mag. load data
Case Length (l3):
2.913" | 74.0mm
Cartridge Length (C.O.L.):
3.600" | 91.4mm
Seated Depth:
0.703" | 17.9mm
Shank Seated Depth:
0.703" | 17.9mm
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_B6249_C577
Last updated:
2025-01-01

Load data for 144 loads in caliber .378 Weath. Mag. with .375 | 300gr | Speer TBBC 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%
57058
89%
**57
100%
ADI AR 2209 👍
<<locked>>
94%
57305
90%
**72
99%
ADI AR 2213
<<locked>>
97%
57087
89%
**02
99%
ADI AR 2217
<<locked>>
97%
42148
66%
**36
96%
ADI AR 2225
<<locked>>
97%
37420
59%
**93
97%
Accurate 2700
<<locked>>
84%
56855
89%
**38
100%
Accurate 3100
<<locked>>
97%
56956
89%
**13
100%
Accurate 4350
<<locked>>
88%
57217
90%
**26
100%
Accurate MAGPRO
<<locked>>
97%
56405
88%
**08
97%
Alliant Reloder-16
<<locked>>
89%
57087
89%
**66
100%
Alliant Reloder-17
<<locked>>
85%
57217
90%
**66
100%
Alliant Reloder-19 👍
<<locked>>
94%
57116
90%
**62
99%
Alliant Reloder-22
<<locked>>
97%
56898
89%
**05
100%
Alliant Reloder-23
<<locked>>
97%
54128
85%
**20
100%
Alliant Reloder-25
<<locked>>
97%
46789
73%
**71
100%
Alliant Reloder-26
<<locked>>
94%
57334
90%
**51
100%
Hodgdon H1000
<<locked>>
97%
42148
66%
**36
96%
Hodgdon H414
<<locked>>
84%
57014
89%
**46
100%
Hodgdon H4350
<<locked>>
91%
57072
89%
**03
100%
Hodgdon H4831
<<locked>>
97%
53026
83%
**77
97%
Hodgdon H4831 SC
<<locked>>
95%
57290
90%
**46
98%
Hodgdon Hybrid 100V
<<locked>>
91%
57406
90%
**90
100%
Hodgdon LVR
<<locked>>
86%
57000
89%
**23
100%
Hodgdon Retumbo
<<locked>>
97%
37420
59%
**93
97%
Hodgdon Superperformance
<<locked>>
87%
57072
89%
**82
100%
Hodgdon VARGET
<<locked>>
83%
57392
90%
**67
100%
IMR 4064
<<locked>>
83%
56898
89%
**51
100%
IMR 4166 Enduron
<<locked>>
85%
57261
90%
**64
100%
IMR 4350
<<locked>>
90%
57203
90%
**07
100%
IMR 4451 Enduron
<<locked>>
86%
57421
90%
**87
100%
IMR 4831
<<locked>>
93%
56855
89%
**10
100%
IMR 4955 Enduron
<<locked>>
96%
57348
90%
**13
98%
IMR 7828 SSC
<<locked>>
96%
57029
89%
**12
99%
[IMR 8133 Enduron]*
<<locked>>
97%
33475
52%
**02
92%
Lovex S065
<<locked>>
87%
57116
90%
**77
100%
Lovex S070
<<locked>>
89%
57421
90%
**07
100%
Lovex S071
<<locked>>
97%
48167
75%
**85
100%
Norma 204
<<locked>>
89%
57232
90%
**43
99%
Norma 217
<<locked>>
97%
33301
52%
**21
95%
Norma MRP 👍
<<locked>>
95%
57072
89%
**28
100%
Norma URP
<<locked>>
89%
57334
90%
**30
100%
Ramshot Hunter
<<locked>>
89%
57087
89%
**53
100%
Ramshot Magnum
<<locked>>
97%
55492
87%
**66
100%
ReloadSwiss RS 14
<<locked>>
97%
36245
57%
**73
100%
ReloadSwiss RS 60
<<locked>>
86%
57305
90%
**85
100%
ReloadSwiss RS 62
<<locked>>
88%
56855
89%
**40
100%
ReloadSwiss RS 70
<<locked>>
89%
56884
89%
**99
100%
ReloadSwiss RS 76
<<locked>>
97%
45701
72%
**10
99%
[ReloadSwiss RS 80]*
<<locked>>
97%
41466
65%
**98
94%
Rottweil R 903
<<locked>>
84%
57232
90%
**71
100%
Rottweil R 904
<<locked>>
93%
56869
89%
**10
99%
Rottweil R 905 👍
<<locked>>
94%
56985
89%
**59
100%
Rottweil R 907
<<locked>>
86%
57130
90%
**84
100%
SNPE Vectan Tubal 5000
<<locked>>
84%
57421
90%
**46
100%
SNPE Vectan Tubal 7000
<<locked>>
87%
57072
89%
**44
100%
Shooters World Long Rifle
<<locked>>
87%
57116
90%
**77
100%
Somchem S355
<<locked>>
84%
57334
90%
**71
100%
Somchem S361
<<locked>>
92%
56898
89%
**80
98%
Somchem S365
<<locked>>
91%
57377
90%
**33
100%
Somchem S385 👍
<<locked>>
94%
57058
89%
**23
100%
Vihtavuori N135
<<locked>>
85%
57174
90%
**72
100%
Vihtavuori N150
<<locked>>
89%
57363
90%
**28
100%
Vihtavuori N160
<<locked>>
86%
57159
90%
**94
100%
Vihtavuori N165
<<locked>>
97%
53040
83%
**57
99%
Vihtavuori N550
<<locked>>
86%
57087
89%
**26
100%
Vihtavuori N555
<<locked>>
95%
57014
89%
**49
100%
Vihtavuori N560
<<locked>>
97%
57392
90%
**28
99%
Vihtavuori N565
<<locked>>
97%
49298
77%
**84
97%
[Vihtavuori N568]*
<<locked>>
97%
42598
67%
**02
94%
Winchester 6.5 StaBALL
<<locked>>
88%
56942
89%
**61
100%
Winchester 760
<<locked>>
84%
57014
89%
**46
100%
Winchester StaBALL HD
<<locked>>
97%
50720
79%
**92
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2208
<<locked>>
81%
53563
84%
**15
100%
ADI AR 2209
<<locked>>
81%
38000
60%
**21
95%
[ADI AR 2213]*
<<locked>>
81%
33968
53%
**49
92%
[ADI AR 2217]*
<<locked>>
88%
31328
49%
**77
90%
[ADI AR 2225]*
<<locked>>
86%
26310
41%
**72
90%
Accurate 2700
<<locked>>
81%
51953
81%
**69
99%
Accurate 3100
<<locked>>
81%
33866
53%
**10
97%
Accurate 4350
<<locked>>
81%
45339
71%
**49
100%
[Accurate MAGPRO]*
<<locked>>
83%
35070
55%
**98
90%
Alliant Reloder-16
<<locked>>
81%
43424
68%
**49
100%
Alliant Reloder-17
<<locked>>
81%
50111
79%
**64
100%
Alliant Reloder-19
<<locked>>
81%
37855
59%
**18
96%
[Alliant Reloder-22]*
<<locked>>
81%
33649
53%
**62
94%
Alliant Reloder-23
<<locked>>
81%
32416
51%
**36
99%
Alliant Reloder-25
<<locked>>
81%
28340
44%
**41
95%
Alliant Reloder-26
<<locked>>
81%
35259
55%
**61
99%
[Hodgdon H1000]*
<<locked>>
88%
31328
49%
**77
90%
Hodgdon H414
<<locked>>
81%
51184
80%
**64
100%
Hodgdon H4350
<<locked>>
81%
41684
65%
**48
98%
[Hodgdon H4831]*
<<locked>>
81%
32068
50%
**67
90%
[Hodgdon H4831 SC]*
<<locked>>
81%
35476
56%
**46
92%
Hodgdon Hybrid 100V
<<locked>>
81%
41118
64%
**44
100%
Hodgdon LVR
<<locked>>
81%
47790
75%
**85
100%
[Hodgdon Retumbo]*
<<locked>>
86%
26310
41%
**72
90%
Hodgdon Superperformance
<<locked>>
81%
46369
73%
**12
99%
Hodgdon VARGET
<<locked>>
81%
53490
84%
**08
100%
IMR 4064
<<locked>>
81%
52982
83%
**92
100%
IMR 4166 Enduron
<<locked>>
81%
51503
81%
**79
100%
IMR 4350
<<locked>>
81%
43903
69%
**87
98%
IMR 4451 Enduron
<<locked>>
81%
49734
78%
**72
99%
IMR 4831
<<locked>>
81%
39305
62%
**18
100%
[IMR 4955 Enduron]*
<<locked>>
81%
35940
56%
**23
93%
[IMR 7828 SSC]*
<<locked>>
81%
34751
54%
**82
92%
[IMR 8133 Enduron]*
<<locked>>
94%
30269
47%
**10
90%
Lovex S065
<<locked>>
81%
47384
74%
**26
100%
Lovex S070
<<locked>>
81%
45687
72%
**20
99%
Lovex S071
<<locked>>
81%
29167
46%
**92
95%
Norma 204
<<locked>>
81%
43671
68%
**23
97%
[Norma 217]*
<<locked>>
89%
26295
41%
**11
90%
Norma MRP
<<locked>>
81%
35230
55%
**31
96%
Norma URP
<<locked>>
81%
44570
70%
**36
100%
Ramshot Hunter
<<locked>>
81%
43482
68%
**30
99%
[Ramshot Magnum]*
<<locked>>
81%
31067
49%
**90
93%
ReloadSwiss RS 14
<<locked>>
93%
34679
54%
**47
100%
ReloadSwiss RS 60
<<locked>>
81%
48399
76%
**57
100%
ReloadSwiss RS 62
<<locked>>
81%
45179
71%
**62
100%
ReloadSwiss RS 70
<<locked>>
81%
43323
68%
**79
100%
[ReloadSwiss RS 76]*
<<locked>>
81%
26585
42%
**11
90%
[ReloadSwiss RS 80]*
<<locked>>
91%
33779
53%
**15
90%
Rottweil R 903
<<locked>>
81%
52707
83%
**02
100%
Rottweil R 904
<<locked>>
81%
39479
62%
**11
95%
Rottweil R 905
<<locked>>
81%
37188
58%
**05
96%
Rottweil R 907
<<locked>>
81%
48675
76%
**52
99%
SNPE Vectan Tubal 5000
<<locked>>
81%
52765
83%
**90
100%
SNPE Vectan Tubal 7000
<<locked>>
81%
46311
73%
**80
99%
Shooters World Long Rifle
<<locked>>
81%
47384
74%
**26
100%
Somchem S355
<<locked>>
81%
52504
82%
**02
100%
[Somchem S361]*
<<locked>>
81%
39914
63%
**95
94%
Somchem S365
<<locked>>
81%
41495
65%
**97
100%
Somchem S385
<<locked>>
81%
37768
59%
**92
97%
Vihtavuori N135
<<locked>>
81%
51039
80%
**97
100%
Vihtavuori N150
<<locked>>
81%
45078
71%
**51
100%
Vihtavuori N160
<<locked>>
81%
47935
75%
**56
100%
[Vihtavuori N165]*
<<locked>>
81%
31763
50%
**51
94%
Vihtavuori N550
<<locked>>
81%
48559
76%
**98
100%
Vihtavuori N555
<<locked>>
81%
36332
57%
**02
99%
[Vihtavuori N560]*
<<locked>>
81%
33837
53%
**79
91%
[Vihtavuori N565]*
<<locked>>
83%
30560
48%
**90
90%
[Vihtavuori N568]*
<<locked>>
91%
34853
55%
**25
90%
Winchester 6.5 StaBALL
<<locked>>
81%
44962
70%
**97
100%
Winchester 760
<<locked>>
81%
51184
80%
**64
100%
Winchester StaBALL HD
<<locked>>
81%
27427
43%
**46
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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