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Load data for .378 Weath. Mag. + .375 | 270gr | Atomic 29 HP

Recommended Powder(s): Alliant Reloder-26, Hodgdon Superperformance, IMR 4831, Ramshot Hunter, ReloadSwiss RS 70

.378 Weath. Mag. + .375 | 270gr | Atomic 29 HP

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.375 | 270gr | Atomic 29 HP
Bullet Weight:
270gr | 17.5g
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_B12242_C577
Last updated:
2026-03-25

Load data for 180 loads in caliber .378 Weath. Mag. with .375 | 270gr | Atomic 29 HP bullet and 90 powders such as Alliant Reloder-26, Hodgdon Superperformance, IMR 4831, Ramshot Hunter, ReloadSwiss RS 70. 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.

    .

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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>>
86%
57174
90%
**05
100%
ADI AR 2209
<<locked>>
97%
56869
89%
**04
99%
ADI AR 2213
<<locked>>
97%
50879
80%
**28
96%
[ADI AR 2225]*
<<locked>>
97%
32634
51%
**77
93%
Accurate 2700
<<locked>>
87%
57290
90%
**82
99%
Accurate 3100
<<locked>>
97%
50314
79%
**53
99%
Accurate 4064
<<locked>>
84%
56869
89%
**72
100%
Accurate 4350
<<locked>>
92%
57217
90%
**74
100%
[Accurate MAGPRO]*
<<locked>>
97%
49255
77%
**28
94%
Alliant Reloder- TS 15.5
<<locked>>
86%
57130
90%
**22
100%
Alliant Reloder-15
<<locked>>
84%
57435
90%
**48
100%
Alliant Reloder-16
<<locked>>
93%
57188
90%
**10
100%
Alliant Reloder-17
<<locked>>
88%
56884
89%
**10
100%
Alliant Reloder-19
<<locked>>
97%
56536
89%
**94
99%
Alliant Reloder-22
<<locked>>
97%
50067
78%
**35
98%
Alliant Reloder-23
<<locked>>
97%
47485
74%
**76
100%
Alliant Reloder-25
<<locked>>
97%
40959
64%
**90
99%
Alliant Reloder-26 👍
<<locked>>
97%
54288
85%
**56
100%
[Baschieri & Pellagri 109]*
<<locked>>
97%
50981
80%
**53
93%
Bofors RP15
<<locked>>
97%
46050
72%
**56
97%
Bofors RP3
<<locked>>
85%
57421
90%
**22
100%
[Bofors RP30]*
<<locked>>
97%
37391
59%
**05
93%
Bofors RP5
<<locked>>
97%
50067
78%
**35
98%
Bofors RP7
<<locked>>
89%
56985
89%
**18
99%
Hodgdon CFE223
<<locked>>
84%
57305
90%
**77
100%
Hodgdon H380
<<locked>>
85%
57116
89%
**38
100%
Hodgdon H414
<<locked>>
88%
56971
89%
**90
100%
Hodgdon H4350
<<locked>>
95%
57276
90%
**41
99%
Hodgdon H4831
<<locked>>
97%
47297
74%
**10
95%
Hodgdon H4831 SC
<<locked>>
97%
53563
84%
**18
96%
Hodgdon Hybrid 100V
<<locked>>
95%
57058
89%
**28
100%
Hodgdon LVR
<<locked>>
90%
57029
89%
**74
100%
[Hodgdon Retumbo]*
<<locked>>
97%
32634
51%
**77
93%
Hodgdon Superperformance 👍
<<locked>>
90%
57101
89%
**23
99%
Hodgdon VARGET
<<locked>>
86%
57174
90%
**05
100%
Hodgdon TrailBoss
<<locked>>
96%
34606
54%
**13
100%
IMR 4064
<<locked>>
87%
57101
89%
**99
100%
IMR 4166 Enduron
<<locked>>
87%
56985
89%
**02
100%
IMR 4350
<<locked>>
93%
57217
90%
**38
99%
IMR 4451 Enduron
<<locked>>
88%
57319
90%
**31
100%
IMR 4831 👍
<<locked>>
97%
57101
89%
**58
100%
IMR 4955 Enduron
<<locked>>
97%
52431
82%
**66
96%
IMR 7828 SSC
<<locked>>
97%
52272
82%
**71
97%
Lovex S062
<<locked>>
84%
56913
89%
**89
100%
Lovex S065
<<locked>>
91%
57305
90%
**18
100%
Lovex S070
<<locked>>
92%
57305
90%
**44
100%
Lovex S071
<<locked>>
97%
41814
66%
**02
98%
Norma 203B
<<locked>>
84%
57203
90%
**38
100%
Norma 204
<<locked>>
92%
57116
90%
**77
99%
Norma MRP
<<locked>>
97%
53011
83%
**10
99%
Norma URP
<<locked>>
92%
57290
90%
**74
100%
Ramshot Big Game
<<locked>>
83%
57305
90%
**48
100%
Ramshot Grand
<<locked>>
97%
56202
88%
**49
98%
Ramshot Hunter 👍
<<locked>>
93%
57116
89%
**90
100%
Ramshot Magnum
<<locked>>
97%
48791
76%
**95
98%
ReloadSwiss RS 14
<<locked>>
97%
35607
56%
**62
100%
ReloadSwiss RS 50
<<locked>>
85%
57072
89%
**22
100%
ReloadSwiss RS 60
<<locked>>
86%
57101
89%
**20
100%
ReloadSwiss RS 62
<<locked>>
92%
57276
90%
**97
100%
ReloadSwiss RS 70 👍
<<locked>>
92%
57058
89%
**46
100%
ReloadSwiss RS 76
<<locked>>
97%
39726
62%
**94
97%
Rottweil R 902
<<locked>>
83%
57348
90%
**79
100%
Rottweil R 903
<<locked>>
87%
57363
90%
**22
100%
Rottweil R 904
<<locked>>
96%
57276
90%
**51
98%
Rottweil R 905
<<locked>>
97%
55912
88%
**81
99%
Rottweil R 907
<<locked>>
89%
56985
89%
**18
99%
SNPE Vectan SP 11
<<locked>>
86%
56840
89%
**48
100%
SNPE Vectan Tubal 5000
<<locked>>
86%
57116
89%
**87
100%
SNPE Vectan Tubal 7000
<<locked>>
91%
57159
90%
**76
100%
Shooters World Long Rifle
<<locked>>
91%
57305
90%
**18
100%
Shooters World Precision
<<locked>>
84%
56913
89%
**89
100%
Somchem S355
<<locked>>
87%
56956
89%
**15
100%
Somchem S361
<<locked>>
95%
56840
89%
**15
97%
Somchem S365
<<locked>>
94%
57159
90%
**81
100%
Somchem S385
<<locked>>
97%
55941
88%
**48
99%
Vihtavuori N133
<<locked>>
83%
57246
90%
**77
100%
Vihtavuori N135
<<locked>>
88%
56985
89%
**20
100%
Vihtavuori N140
<<locked>>
83%
56985
89%
**33
100%
Vihtavuori N150
<<locked>>
92%
57261
90%
**76
100%
Vihtavuori N160
<<locked>>
90%
56942
89%
**38
100%
Vihtavuori N165
<<locked>>
97%
46833
73%
**90
97%
Vihtavuori N540
<<locked>>
83%
56956
89%
**69
100%
Vihtavuori N550
<<locked>>
90%
57377
90%
**84
100%
Vihtavuori N555
<<locked>>
97%
52779
83%
**48
100%
Vihtavuori N560
<<locked>>
97%
50473
79%
**61
96%
[Vihtavuori N565]*
<<locked>>
97%
42235
66%
**87
94%
Winchester 6.5 StaBALL
<<locked>>
91%
56898
89%
**05
100%
Winchester 760
<<locked>>
88%
56971
89%
**90
100%
Winchester StaBALL HD
<<locked>>
97%
42293
66%
**22
100%
Winchester Supreme 780
<<locked>>
96%
57014
89%
**61
99%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2208
<<locked>>
81%
48863
77%
**77
100%
[ADI AR 2209]*
<<locked>>
81%
33736
53%
**38
92%
[ADI AR 2213]*
<<locked>>
86%
34693
54%
**80
90%
[ADI AR 2225]*
<<locked>>
93%
29037
45%
**62
90%
Accurate 2700
<<locked>>
81%
46862
73%
**12
98%
[Accurate 3100]*
<<locked>>
81%
28732
45%
**00
93%
Accurate 4064
<<locked>>
81%
51445
81%
**94
100%
Accurate 4350
<<locked>>
81%
39581
62%
**79
99%
[Accurate MAGPRO]*
<<locked>>
90%
38798
61%
**12
90%
Alliant Reloder- TS 15.5
<<locked>>
81%
49371
77%
**07
100%
Alliant Reloder-15
<<locked>>
81%
52881
83%
**76
100%
Alliant Reloder-16
<<locked>>
81%
38522
60%
**92
99%
Alliant Reloder-17
<<locked>>
81%
44208
69%
**17
100%
[Alliant Reloder-19]*
<<locked>>
81%
33504
52%
**38
92%
[Alliant Reloder-22]*
<<locked>>
82%
30052
47%
**85
90%
Alliant Reloder-23
<<locked>>
81%
27949
44%
**36
97%
[Alliant Reloder-25]*
<<locked>>
82%
25295
40%
**47
90%
Alliant Reloder-26
<<locked>>
81%
29936
47%
**41
95%
[Baschieri & Pellagri 109]*
<<locked>>
92%
43772
69%
**12
90%
[Bofors RP15]*
<<locked>>
85%
30589
48%
**02
90%
Bofors RP3
<<locked>>
81%
49661
78%
**17
100%
[Bofors RP30]*
<<locked>>
93%
32387
51%
**74
90%
[Bofors RP5]*
<<locked>>
82%
30052
47%
**85
90%
Bofors RP7
<<locked>>
81%
43627
68%
**92
97%
Hodgdon CFE223
<<locked>>
81%
52243
82%
**95
100%
Hodgdon H380
<<locked>>
81%
50067
78%
**26
100%
Hodgdon H414
<<locked>>
81%
45629
71%
**00
98%
Hodgdon H4350
<<locked>>
81%
37202
58%
**74
95%
[Hodgdon H4831]*
<<locked>>
88%
35447
56%
**61
90%
[Hodgdon H4831 SC]*
<<locked>>
85%
35447
56%
**61
90%
Hodgdon Hybrid 100V
<<locked>>
81%
35897
56%
**74
99%
Hodgdon LVR
<<locked>>
81%
42569
67%
**28
99%
[Hodgdon Retumbo]*
<<locked>>
93%
29037
45%
**62
90%
Hodgdon Superperformance
<<locked>>
81%
40843
64%
**38
97%
Hodgdon VARGET
<<locked>>
81%
48472
76%
**71
100%
Hodgdon TrailBoss
<<locked>>
81%
27688
43%
**68
100%
IMR 4064
<<locked>>
81%
47863
75%
**61
100%
IMR 4166 Enduron
<<locked>>
81%
47152
74%
**31
98%
IMR 4350
<<locked>>
81%
39262
62%
**16
96%
IMR 4451 Enduron
<<locked>>
81%
45194
71%
**25
98%
IMR 4831
<<locked>>
81%
34345
54%
**44
98%
[IMR 4955 Enduron]*
<<locked>>
83%
34432
54%
**05
90%
[IMR 7828 SSC]*
<<locked>>
85%
34563
54%
**93
90%
Lovex S062
<<locked>>
81%
51430
81%
**03
100%
Lovex S065
<<locked>>
81%
42293
66%
**69
98%
Lovex S070
<<locked>>
81%
40611
64%
**49
97%
[Lovex S071]*
<<locked>>
81%
24627
39%
**78
90%
Norma 203B
<<locked>>
81%
52112
82%
**59
100%
[Norma 204]*
<<locked>>
81%
38609
61%
**46
94%
[Norma MRP]*
<<locked>>
81%
30269
47%
**15
92%
Norma URP
<<locked>>
81%
39421
62%
**72
99%
Ramshot Big Game
<<locked>>
81%
52736
83%
**82
100%
[Ramshot Grand]*
<<locked>>
83%
33895
53%
**87
90%
Ramshot Hunter
<<locked>>
81%
38101
60%
**59
97%
[Ramshot Magnum]*
<<locked>>
84%
29530
46%
**59
90%
ReloadSwiss RS 14
<<locked>>
81%
28224
44%
**11
100%
ReloadSwiss RS 50
<<locked>>
81%
50227
79%
**20
99%
ReloadSwiss RS 60
<<locked>>
81%
46963
74%
**66
100%
ReloadSwiss RS 62
<<locked>>
81%
39508
62%
**92
99%
ReloadSwiss RS 70
<<locked>>
81%
38363
60%
**05
98%
[ReloadSwiss RS 76]*
<<locked>>
89%
29747
47%
**15
90%
Rottweil R 902
<<locked>>
81%
53258
83%
**13
100%
Rottweil R 903
<<locked>>
81%
46978
74%
**67
100%
[Rottweil R 904]*
<<locked>>
81%
35114
55%
**31
91%
[Rottweil R 905]*
<<locked>>
81%
32329
51%
**15
92%
Rottweil R 907
<<locked>>
81%
43627
68%
**92
97%
SNPE Vectan SP 11
<<locked>>
81%
48138
75%
**20
100%
SNPE Vectan Tubal 5000
<<locked>>
81%
48225
76%
**69
100%
SNPE Vectan Tubal 7000
<<locked>>
81%
41568
65%
**20
97%
Shooters World Long Rifle
<<locked>>
81%
42293
66%
**69
98%
Shooters World Precision
<<locked>>
81%
51430
81%
**03
100%
Somchem S355
<<locked>>
81%
47050
74%
**57
100%
[Somchem S361]*
<<locked>>
81%
35447
56%
**18
90%
Somchem S365
<<locked>>
81%
35723
56%
**26
100%
[Somchem S385]*
<<locked>>
81%
32880
52%
**02
93%
Vihtavuori N133
<<locked>>
81%
53708
84%
**28
100%
Vihtavuori N135
<<locked>>
81%
45701
72%
**66
100%
Vihtavuori N140
<<locked>>
81%
53461
84%
**90
100%
Vihtavuori N150
<<locked>>
81%
40364
63%
**10
100%
Vihtavuori N160
<<locked>>
81%
42482
67%
**95
99%
[Vihtavuori N165]*
<<locked>>
82%
28645
45%
**80
90%
Vihtavuori N540
<<locked>>
81%
52953
83%
**10
100%
Vihtavuori N550
<<locked>>
81%
43134
68%
**48
99%
Vihtavuori N555
<<locked>>
81%
31067
49%
**15
97%
[Vihtavuori N560]*
<<locked>>
86%
35186
55%
**26
90%
[Vihtavuori N565]*
<<locked>>
90%
33707
53%
**93
90%
Winchester 6.5 StaBALL
<<locked>>
81%
40059
63%
**43
100%
Winchester 760
<<locked>>
81%
45629
71%
**00
98%
Winchester StaBALL HD
<<locked>>
81%
24497
38%
**00
95%
[Winchester Supreme 780]*
<<locked>>
81%
32779
51%
**98
92%

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

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