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Load data for .338-378 Weath. Mag. + .338 | 231gr | Lapua Naturalis

Recommended Powder(s): Hodgdon H4831, ReloadSwiss RS 76, ReloadSwiss RS 80, Vihtavuori N565, Vihtavuori N568

.338-378 Weath. Mag. + .338 | 231gr | Lapua Naturalis

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.338 | 231gr | Lapua Naturalis
Manufacturer SKU:
NPL8020 | N508
Bullet Weight:
231gr | 15.0g
Bullet Diameter:
0.338" | 8.59mm
Bullet Length:
1.350" | 34.3mm
Caliber:
.338-378 Weath. Mag. load data
Case Length (l3):
2.910" | 73.9mm
Cartridge Length (C.O.L.):
3.694" | 93.8mm
Seated Depth:
0.566" | 14.4mm
Shank Seated Depth:
0.566" | 14.4mm
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_B3196_C472
Last updated:
2025-09-18

Load data for 92 loads in caliber .338-378 Weath. Mag. with .338 | 231gr | Lapua Naturalis bullet and 46 powders such as Hodgdon H4831, ReloadSwiss RS 76, ReloadSwiss RS 80, Vihtavuori N565, Vihtavuori N568. 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 2209
<<locked>>
86%
57087
89%
**00
100%
ADI AR 2213
<<locked>>
89%
57217
90%
**40
100%
ADI AR 2217
<<locked>>
97%
55376
87%
**07
100%
ADI AR 2218
<<locked>>
97%
48617
76%
**71
95%
ADI AR 2225
<<locked>>
97%
50444
79%
**84
100%
Accurate 3100
<<locked>>
89%
57377
90%
**41
100%
Accurate MAGPRO
<<locked>>
89%
57290
90%
**49
99%
Alliant Reloder-19
<<locked>>
86%
57029
89%
**97
100%
Alliant Reloder-22
<<locked>>
89%
57392
90%
**33
100%
Alliant Reloder-23
<<locked>>
90%
56840
89%
**71
100%
Alliant Reloder-25
<<locked>>
94%
57406
90%
**40
100%
Alliant Reloder-26
<<locked>>
85%
57087
89%
**46
100%
Alliant Reloder-33
<<locked>>
97%
53519
84%
**46
97%
[Alliant Reloder-50]*
<<locked>>
97%
45934
72%
**95
94%
Hodgdon H1000
<<locked>>
97%
55376
87%
**07
100%
Hodgdon H4350
<<locked>>
84%
57290
90%
**48
100%
Hodgdon H4831 👍
<<locked>>
92%
57392
90%
**94
99%
Hodgdon H4831 SC
<<locked>>
88%
57159
90%
**87
99%
Hodgdon Hybrid 100V
<<locked>>
84%
57188
90%
**15
100%
Hodgdon Retumbo
<<locked>>
97%
50444
79%
**84
100%
Hodgdon TrailBoss
<<locked>>
97%
36303
57%
**04
100%
IMR 4831
<<locked>>
85%
56956
89%
**31
100%
IMR 4955 Enduron
<<locked>>
89%
57421
90%
**64
99%
IMR 7828 SSC
<<locked>>
88%
57276
90%
**46
100%
[IMR 7977 Enduron]*
<<locked>>
94%
56942
89%
**22
94%
IMR 8133 Enduron
<<locked>>
97%
46485
73%
**92
98%
[Lovex D100]*
<<locked>>
97%
55245
87%
**18
92%
Lovex S071
<<locked>>
94%
57101
89%
**41
100%
Norma 217
<<locked>>
97%
47616
75%
**31
100%
Norma MRP
<<locked>>
87%
57276
90%
**43
100%
Ramshot Magnum
<<locked>>
89%
57174
90%
**07
100%
ReloadSwiss RS 14
<<locked>>
97%
37144
58%
**44
100%
ReloadSwiss RS 76 👍
<<locked>>
94%
57087
89%
**09
100%
ReloadSwiss RS 80 👍
<<locked>>
96%
57377
90%
**89
99%
Rottweil R 904
<<locked>>
86%
56971
89%
**58
100%
Rottweil R 905
<<locked>>
86%
56840
89%
**94
100%
Somchem S361
<<locked>>
85%
57000
89%
**25
99%
Somchem S385
<<locked>>
86%
57203
90%
**54
100%
Vihtavuori N165
<<locked>>
91%
57377
90%
**48
100%
Vihtavuori N170
<<locked>>
97%
51808
81%
**92
95%
Vihtavuori N555
<<locked>>
86%
57305
90%
**74
100%
Vihtavuori N560
<<locked>>
88%
57072
89%
**56
99%
Vihtavuori N565 👍
<<locked>>
92%
56855
89%
**23
99%
Vihtavuori N568 👍
<<locked>>
96%
57377
90%
**79
99%
Vihtavuori N570
<<locked>>
97%
57072
89%
**18
97%
Winchester StaBALL HD
<<locked>>
90%
57188
90%
**69
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2209
<<locked>>
81%
48530
76%
**62
99%
ADI AR 2213
<<locked>>
81%
43642
68%
**00
97%
[ADI AR 2217]*
<<locked>>
81%
32909
52%
**44
93%
[ADI AR 2218]*
<<locked>>
90%
38014
60%
**28
90%
ADI AR 2225
<<locked>>
81%
30284
47%
**21
96%
Accurate 3100
<<locked>>
81%
45020
71%
**48
100%
Accurate MAGPRO
<<locked>>
81%
43801
69%
**10
96%
Alliant Reloder-19
<<locked>>
81%
48501
76%
**59
99%
Alliant Reloder-22
<<locked>>
81%
44512
70%
**07
99%
Alliant Reloder-23
<<locked>>
81%
43352
68%
**61
100%
Alliant Reloder-25
<<locked>>
81%
37623
59%
**95
100%
Alliant Reloder-26
<<locked>>
81%
48979
77%
**18
100%
[Alliant Reloder-33]*
<<locked>>
86%
35810
56%
**69
90%
[Alliant Reloder-50]*
<<locked>>
91%
36738
58%
**95
90%
[Hodgdon H1000]*
<<locked>>
81%
32909
52%
**44
93%
Hodgdon H4350
<<locked>>
81%
51837
81%
**59
100%
Hodgdon H4831
<<locked>>
81%
41031
64%
**95
96%
Hodgdon H4831 SC
<<locked>>
81%
45585
71%
**84
97%
Hodgdon Hybrid 100V
<<locked>>
81%
52431
82%
**46
100%
Hodgdon Retumbo
<<locked>>
81%
30284
47%
**21
96%
Hodgdon TrailBoss
<<locked>>
81%
28834
45%
**47
100%
IMR 4831
<<locked>>
81%
50082
78%
**30
100%
IMR 4955 Enduron
<<locked>>
81%
44904
70%
**48
97%
IMR 7828 SSC
<<locked>>
81%
45034
71%
**40
98%
[IMR 7977 Enduron]*
<<locked>>
86%
43961
69%
**85
90%
[IMR 8133 Enduron]*
<<locked>>
81%
27920
44%
**43
90%
[Lovex D100]*
<<locked>>
93%
48066
75%
**03
90%
Lovex S071
<<locked>>
81%
38928
61%
**26
99%
[Norma 217]*
<<locked>>
81%
28079
44%
**65
93%
Norma MRP
<<locked>>
81%
47239
74%
**79
100%
Ramshot Magnum
<<locked>>
81%
42221
66%
**61
99%
ReloadSwiss RS 14
<<locked>>
81%
29646
46%
**90
100%
ReloadSwiss RS 76
<<locked>>
81%
35998
56%
**12
98%
[ReloadSwiss RS 80]*
<<locked>>
81%
33098
52%
**97
92%
Rottweil R 904
<<locked>>
81%
49356
77%
**36
99%
Rottweil R 905
<<locked>>
81%
48109
75%
**40
99%
Somchem S361
<<locked>>
81%
50473
79%
**30
98%
Somchem S385
<<locked>>
81%
48660
76%
**20
100%
Vihtavuori N165
<<locked>>
81%
41263
65%
**69
98%
[Vihtavuori N170]*
<<locked>>
88%
39407
62%
**46
90%
Vihtavuori N555
<<locked>>
81%
48298
76%
**33
100%
Vihtavuori N560
<<locked>>
81%
44657
70%
**36
97%
Vihtavuori N565
<<locked>>
81%
39204
61%
**95
96%
[Vihtavuori N568]*
<<locked>>
81%
34229
54%
**16
92%
[Vihtavuori N570]*
<<locked>>
84%
36753
58%
**02
90%
Winchester StaBALL HD
<<locked>>
81%
41060
64%
**10
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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