top of page

Load data for .378 Weath. Mag. + .375 | 305gr | Hammer Claw Hammer

Recommended Powder(s): Alliant Reloder-19, Alliant Reloder-22, Bofors RP5, Norma MRP, Rottweil R 905

.378 Weath. Mag. + .375 | 305gr | Hammer Claw Hammer

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.375 | 305gr | Hammer Claw Hammer
Manufacturer SKU:
37305CH
Bullet Weight:
305gr | 19.8g
Bullet Diameter:
0.375" | 9.52mm
Bullet Length:
<<locked>>
Caliber:
.378 Weath. Mag. load data
Case Length (l3):
2.913" | 74.0mm
Cartridge Length (C.O.L.):
<<locked>>
Seated Depth:
<<locked>>
Shank Seated Depth:
<<locked>>
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_B12298_C577
Last updated:
2026-03-07
Recommended Twist Rate:
1:17 - 1:15

Load data for 152 loads in caliber .378 Weath. Mag. with .375 | 305gr | Hammer Claw Hammer bullet and 76 powders such as Alliant Reloder-19, Alliant Reloder-22, Bofors RP5, Norma MRP, Rottweil R 905. 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".

  • No data yet

  • We recommend you limit powder range to relevant brands to speed up re-calculation of results

    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.

    .

    Loading_icon.gif

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 2209
<<locked>>
93%
57087
89%
**49
100%
ADI AR 2213
<<locked>>
96%
57058
89%
**95
99%
ADI AR 2217
<<locked>>
97%
42844
67%
**43
96%
ADI AR 2225
<<locked>>
97%
38319
60%
**10
98%
Accurate 2700
<<locked>>
83%
57377
90%
**35
100%
Accurate 3100
<<locked>>
96%
57101
89%
**97
100%
Accurate 4350
<<locked>>
87%
57014
89%
**10
100%
Accurate MAGPRO
<<locked>>
97%
57377
90%
**12
98%
Alliant Reloder-16
<<locked>>
89%
57145
90%
**49
100%
Alliant Reloder-17
<<locked>>
84%
56855
89%
**46
100%
Alliant Reloder-19 👍
<<locked>>
93%
56898
89%
**53
100%
Alliant Reloder-22 👍
<<locked>>
96%
57261
90%
**92
100%
Alliant Reloder-23
<<locked>>
97%
55637
87%
**23
100%
Alliant Reloder-25
<<locked>>
97%
47993
75%
**77
100%
Alliant Reloder-26
<<locked>>
93%
56956
89%
**22
100%
Baschieri & Pellagri 109
<<locked>>
97%
57043
89%
**26
96%
Bofors RP15
<<locked>>
97%
53679
84%
**40
99%
Bofors RP30
<<locked>>
97%
44353
70%
**15
97%
Bofors RP5 👍
<<locked>>
96%
57261
90%
**92
100%
Bofors RP7
<<locked>>
86%
57406
90%
**74
100%
Hodgdon H1000
<<locked>>
97%
42844
67%
**43
96%
Hodgdon H414
<<locked>>
84%
57145
90%
**36
100%
Hodgdon H4350
<<locked>>
91%
57319
90%
**94
100%
Hodgdon H4831
<<locked>>
97%
54128
85%
**84
98%
Hodgdon H4831 SC
<<locked>>
95%
57101
89%
**30
98%
Hodgdon Hybrid 100V
<<locked>>
91%
57174
90%
**71
100%
Hodgdon LVR
<<locked>>
86%
57232
90%
**17
100%
Hodgdon Retumbo
<<locked>>
97%
38319
60%
**10
98%
Hodgdon Superperformance
<<locked>>
86%
57159
90%
**69
100%
Hodgdon TrailBoss
<<locked>>
97%
35650
56%
**34
100%
IMR 4064
<<locked>>
83%
57159
90%
**38
100%
IMR 4166 Enduron
<<locked>>
84%
57087
89%
**51
100%
IMR 4350
<<locked>>
89%
56913
89%
**87
100%
IMR 4451 Enduron
<<locked>>
85%
57276
90%
**77
100%
IMR 4831
<<locked>>
92%
57174
90%
**94
100%
IMR 4955 Enduron
<<locked>>
95%
57014
89%
**00
99%
IMR 7828 SSC
<<locked>>
95%
57435
90%
**08
99%
[IMR 8133 Enduron]*
<<locked>>
97%
34272
54%
**15
93%
Lovex S065
<<locked>>
87%
57421
90%
**67
100%
Lovex S070
<<locked>>
88%
57377
90%
**87
100%
Lovex S071
<<locked>>
97%
49081
77%
**89
100%
Norma 204
<<locked>>
88%
56855
89%
**30
99%
Norma 217
<<locked>>
97%
34301
54%
**44
96%
Norma MRP 👍
<<locked>>
94%
57000
89%
**08
100%
Norma URP
<<locked>>
88%
57101
89%
**10
100%
Ramshot Grand
<<locked>>
93%
57145
90%
**15
99%
Ramshot Hunter
<<locked>>
89%
57334
90%
**46
100%
Ramshot Magnum
<<locked>>
97%
57072
89%
**76
100%
ReloadSwiss RS 14
<<locked>>
96%
36172
57%
**70
100%
ReloadSwiss RS 62
<<locked>>
87%
56927
89%
**33
100%
ReloadSwiss RS 70
<<locked>>
88%
57101
89%
**85
100%
ReloadSwiss RS 76
<<locked>>
97%
46978
74%
**26
100%
ReloadSwiss RS 80
<<locked>>
97%
42525
67%
**12
95%
Rottweil R 904
<<locked>>
92%
57043
89%
**03
99%
Rottweil R 905 👍
<<locked>>
93%
57348
90%
**53
100%
Rottweil R 907
<<locked>>
86%
57406
90%
**74
100%
SNPE Vectan Tubal 5000
<<locked>>
83%
57261
90%
**30
100%
SNPE Vectan Tubal 7000
<<locked>>
87%
56884
89%
**31
100%
Shooters World Long Rifle
<<locked>>
87%
57421
90%
**67
100%
Somchem S355
<<locked>>
83%
57435
90%
**54
100%
Somchem S361
<<locked>>
91%
57188
90%
**80
98%
Somchem S365
<<locked>>
90%
57174
90%
**17
100%
Somchem S385
<<locked>>
93%
57363
90%
**20
100%
Vihtavuori N135
<<locked>>
84%
57363
90%
**62
100%
Vihtavuori N150
<<locked>>
88%
57130
90%
**15
100%
Vihtavuori N160
<<locked>>
86%
56913
89%
**74
100%
Vihtavuori N165
<<locked>>
97%
54288
85%
**64
100%
Vihtavuori N550
<<locked>>
85%
57043
89%
**10
100%
Vihtavuori N555
<<locked>>
94%
56811
89%
**33
100%
Vihtavuori N560
<<locked>>
96%
57305
90%
**18
99%
Vihtavuori N565
<<locked>>
97%
50328
79%
**87
98%
Vihtavuori N568
<<locked>>
97%
43903
69%
**21
95%
Winchester 6.5 StaBALL
<<locked>>
87%
56884
89%
**44
100%
Winchester 760
<<locked>>
84%
57145
90%
**36
100%
Winchester StaBALL HD
<<locked>>
97%
53026
83%
**05
100%
Winchester Supreme 780
<<locked>>
92%
56985
89%
**07
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2209
<<locked>>
81%
38725
61%
**34
96%
[ADI AR 2213]*
<<locked>>
81%
34519
54%
**56
93%
[ADI AR 2217]*
<<locked>>
86%
30574
48%
**54
90%
[ADI AR 2225]*
<<locked>>
84%
25614
40%
**46
90%
Accurate 2700
<<locked>>
81%
52939
83%
**75
100%
Accurate 3100
<<locked>>
81%
34389
54%
**06
97%
Accurate 4350
<<locked>>
81%
46267
73%
**49
100%
[Accurate MAGPRO]*
<<locked>>
82%
34200
54%
**75
90%
Alliant Reloder-16
<<locked>>
81%
44396
70%
**52
100%
Alliant Reloder-17
<<locked>>
81%
51300
80%
**64
100%
Alliant Reloder-19
<<locked>>
81%
38609
61%
**21
96%
Alliant Reloder-22
<<locked>>
81%
34316
54%
**72
95%
Alliant Reloder-23
<<locked>>
81%
32996
52%
**36
100%
Alliant Reloder-25
<<locked>>
81%
28747
45%
**54
96%
Alliant Reloder-26
<<locked>>
81%
36042
56%
**67
99%
[Baschieri & Pellagri 109]*
<<locked>>
84%
37985
60%
**62
90%
[Bofors RP15]*
<<locked>>
81%
31981
50%
**06
93%
[Bofors RP30]*
<<locked>>
84%
28776
45%
**51
90%
Bofors RP5
<<locked>>
81%
34316
54%
**72
95%
Bofors RP7
<<locked>>
81%
49240
77%
**49
99%
[Hodgdon H1000]*
<<locked>>
86%
30574
48%
**54
90%
Hodgdon H414
<<locked>>
81%
52214
82%
**67
100%
Hodgdon H4350
<<locked>>
81%
42453
67%
**51
98%
[Hodgdon H4831]*
<<locked>>
81%
32518
51%
**70
91%
[Hodgdon H4831 SC]*
<<locked>>
81%
36289
57%
**59
93%
Hodgdon Hybrid 100V
<<locked>>
81%
42047
66%
**48
100%
Hodgdon LVR
<<locked>>
81%
48675
76%
**85
100%
[Hodgdon Retumbo]*
<<locked>>
84%
25614
40%
**46
90%
Hodgdon Superperformance
<<locked>>
81%
47413
74%
**15
99%
Hodgdon TrailBoss
<<locked>>
81%
28326
44%
**90
100%
IMR 4064
<<locked>>
81%
53722
84%
**92
100%
IMR 4166 Enduron
<<locked>>
81%
52330
82%
**79
100%
IMR 4350
<<locked>>
81%
44440
70%
**90
99%
IMR 4451 Enduron
<<locked>>
81%
50720
79%
**79
100%
IMR 4831
<<locked>>
81%
40103
63%
**21
100%
[IMR 4955 Enduron]*
<<locked>>
81%
36622
57%
**29
93%
[IMR 7828 SSC]*
<<locked>>
81%
35157
55%
**88
93%
[IMR 8133 Enduron]*
<<locked>>
92%
29559
46%
**80
90%
Lovex S065
<<locked>>
81%
48196
76%
**26
100%
Lovex S070
<<locked>>
81%
46354
73%
**20
99%
Lovex S071
<<locked>>
81%
29660
46%
**95
96%
Norma 204
<<locked>>
81%
44425
70%
**23
98%
[Norma 217]*
<<locked>>
88%
25904
41%
**92
90%
Norma MRP
<<locked>>
81%
35984
56%
**38
97%
Norma URP
<<locked>>
81%
45469
71%
**39
100%
[Ramshot Grand]*
<<locked>>
81%
36332
57%
**34
94%
Ramshot Hunter
<<locked>>
81%
44280
69%
**39
99%
[Ramshot Magnum]*
<<locked>>
81%
31676
50%
**06
94%
ReloadSwiss RS 14
<<locked>>
81%
28848
45%
**26
100%
ReloadSwiss RS 62
<<locked>>
81%
46093
72%
**66
100%
ReloadSwiss RS 70
<<locked>>
81%
44396
70%
**85
100%
[ReloadSwiss RS 76]*
<<locked>>
81%
27093
42%
**24
91%
[ReloadSwiss RS 80]*
<<locked>>
90%
33156
52%
**92
90%
Rottweil R 904
<<locked>>
81%
40001
63%
**11
95%
Rottweil R 905
<<locked>>
81%
37898
59%
**08
96%
Rottweil R 907
<<locked>>
81%
49240
77%
**49
99%
SNPE Vectan Tubal 5000
<<locked>>
81%
53679
84%
**87
100%
SNPE Vectan Tubal 7000
<<locked>>
81%
47224
74%
**80
99%
Shooters World Long Rifle
<<locked>>
81%
48196
76%
**26
100%
Somchem S355
<<locked>>
81%
53432
84%
**98
100%
Somchem S361
<<locked>>
81%
40741
64%
**02
95%
Somchem S365
<<locked>>
81%
42235
66%
**93
100%
Somchem S385
<<locked>>
81%
38682
61%
**02
97%
Vihtavuori N135
<<locked>>
81%
51808
81%
**90
100%
Vihtavuori N150
<<locked>>
81%
46006
72%
**54
100%
Vihtavuori N160
<<locked>>
81%
48776
76%
**59
100%
[Vihtavuori N165]*
<<locked>>
81%
32358
51%
**54
94%
Vihtavuori N550
<<locked>>
81%
49472
78%
**02
100%
Vihtavuori N555
<<locked>>
81%
37144
58%
**15
100%
[Vihtavuori N560]*
<<locked>>
81%
34447
54%
**79
92%
[Vihtavuori N565]*
<<locked>>
82%
30008
47%
**64
90%
[Vihtavuori N568]*
<<locked>>
89%
33939
53%
**95
90%
Winchester 6.5 StaBALL
<<locked>>
81%
45832
72%
**97
100%
Winchester 760
<<locked>>
81%
52214
82%
**67
100%
Winchester StaBALL HD
<<locked>>
81%
28224
44%
**56
100%
Winchester Supreme 780
<<locked>>
81%
38319
60%
**98
96%

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.

<<locked>>... you need to buy an access license to unlock the data

bottom of page