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Load data for .338-378 Weath. Mag. + .338 | 250gr | Norma GTX

Recommended Powder(s): Bofors RP30, Hodgdon H1000, Hodgdon Retumbo, IMR 7828 SSC, Vihtavuori N565

.338-378 Weath. Mag. + .338 | 250gr | Norma GTX

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.338 | 250gr | Norma GTX
Manufacturer SKU:
10685031
Bullet Weight:
250gr | 16.2g
Bullet Diameter:
0.338" | 8.59mm
Bullet Length:
<<locked>>
Caliber:
.338-378 Weath. Mag. load data
Case Length (l3):
2.910" | 73.9mm
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_B10819_C472
Last updated:
2026-06-01

Load data for 106 loads in caliber .338-378 Weath. Mag. with .338 | 250gr | Norma GTX bullet and 53 powders such as Bofors RP30, Hodgdon H1000, Hodgdon Retumbo, IMR 7828 SSC, Vihtavuori N565. 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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  • 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 2209
<<locked>>
86%
56927
89%
**05
100%
ADI AR 2213
<<locked>>
89%
57203
90%
**48
100%
ADI AR 2217
<<locked>>
97%
55143
86%
**22
100%
ADI AR 2218
<<locked>>
97%
47834
75%
**82
96%
ADI AR 2225
<<locked>>
97%
50285
79%
**89
100%
Accurate 3100
<<locked>>
89%
56884
89%
**43
100%
Accurate MAGPRO
<<locked>>
87%
56855
89%
**58
99%
Alliant Reloder-19
<<locked>>
86%
56898
89%
**02
100%
Alliant Reloder-22
<<locked>>
89%
57029
89%
**35
100%
Alliant Reloder-23
<<locked>>
90%
57174
90%
**76
100%
Alliant Reloder-25
<<locked>>
94%
57348
90%
**41
100%
Alliant Reloder-26
<<locked>>
86%
57363
90%
**54
100%
Alliant Reloder-33
<<locked>>
97%
52997
83%
**44
97%
Alliant Reloder-50
<<locked>>
97%
45078
71%
**97
95%
Baschieri & Pellagri 109
<<locked>>
91%
57188
90%
**99
98%
Bofors RP15
<<locked>>
91%
57000
89%
**31
100%
Bofors RP30 👍
<<locked>>
96%
57072
89%
**61
100%
Bofors RP5
<<locked>>
89%
57029
89%
**35
100%
Hodgdon H1000 👍
<<locked>>
95%
57246
90%
**41
100%
Hodgdon H4831
<<locked>>
87%
57334
90%
**92
100%
Hodgdon H4831 SC
<<locked>>
88%
57101
89%
**95
100%
Hodgdon Hybrid 100V
<<locked>>
84%
57043
89%
**13
100%
Hodgdon Retumbo 👍
<<locked>>
94%
57130
90%
**43
100%
Hodgdon TrailBoss
<<locked>>
97%
36201
57%
**29
100%
IMR 4955 Enduron
<<locked>>
87%
57145
90%
**66
100%
IMR 7828 SSC 👍
<<locked>>
90%
57145
90%
**54
100%
IMR 7977 Enduron
<<locked>>
94%
57029
89%
**30
95%
IMR 8133 Enduron
<<locked>>
97%
46311
73%
**07
99%
[Lovex D100]*
<<locked>>
97%
54752
86%
**36
93%
Lovex S071
<<locked>>
94%
57305
90%
**43
100%
Norma 217
<<locked>>
97%
46702
73%
**23
100%
Norma MRP
<<locked>>
87%
57435
90%
**58
100%
Ramshot Grand
<<locked>>
89%
57406
90%
**64
100%
Ramshot Magnum
<<locked>>
92%
57334
90%
**18
100%
ReloadSwiss RS 14
<<locked>>
96%
36811
58%
**62
100%
ReloadSwiss RS 76
<<locked>>
94%
57334
90%
**23
100%
ReloadSwiss RS 80
<<locked>>
96%
56913
89%
**00
100%
Rottweil R 904
<<locked>>
86%
57159
90%
**72
100%
Rottweil R 905
<<locked>>
86%
56884
89%
**95
100%
[SNPE Vectan SP 13]*
<<locked>>
97%
39668
62%
**16
92%
SNPE Vectan Tubal 8000
<<locked>>
87%
57116
90%
**99
100%
[Shooters World 50 BMG]*
<<locked>>
97%
54752
86%
**36
93%
Somchem S361
<<locked>>
85%
57290
90%
**43
100%
Somchem S385
<<locked>>
86%
57029
89%
**66
100%
Vihtavuori N165
<<locked>>
90%
57145
90%
**53
100%
Vihtavuori N170
<<locked>>
95%
57000
89%
**82
97%
Vihtavuori N555
<<locked>>
87%
56898
89%
**72
100%
Vihtavuori N560
<<locked>>
87%
56971
89%
**64
100%
Vihtavuori N565 👍
<<locked>>
93%
57130
90%
**38
100%
Vihtavuori N568
<<locked>>
96%
57029
89%
**81
99%
Vihtavuori N570
<<locked>>
97%
55898
88%
**10
98%
Winchester StaBALL HD
<<locked>>
90%
56898
89%
**61
100%
Winchester Supreme 780
<<locked>>
88%
57174
90%
**69
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2209
<<locked>>
81%
48298
76%
**61
99%
ADI AR 2213
<<locked>>
81%
43366
68%
**12
98%
[ADI AR 2217]*
<<locked>>
81%
32300
51%
**56
94%
[ADI AR 2218]*
<<locked>>
89%
35969
56%
**03
90%
ADI AR 2225
<<locked>>
81%
29559
46%
**29
96%
Accurate 3100
<<locked>>
81%
43961
69%
**39
100%
Accurate MAGPRO
<<locked>>
81%
45585
71%
**61
97%
Alliant Reloder-19
<<locked>>
81%
48051
75%
**54
99%
Alliant Reloder-22
<<locked>>
81%
44019
69%
**18
99%
Alliant Reloder-23
<<locked>>
81%
42743
67%
**52
100%
Alliant Reloder-25
<<locked>>
81%
36840
58%
**93
100%
Alliant Reloder-26
<<locked>>
81%
48283
76%
**17
100%
[Alliant Reloder-33]*
<<locked>>
85%
33678
53%
**41
90%
[Alliant Reloder-50]*
<<locked>>
90%
35041
55%
**74
90%
Baschieri & Pellagri 109
<<locked>>
81%
41959
66%
**30
95%
Bofors RP15
<<locked>>
81%
40959
64%
**52
98%
Bofors RP30
<<locked>>
81%
34374
54%
**31
96%
Bofors RP5
<<locked>>
81%
44019
69%
**18
99%
Hodgdon H1000
<<locked>>
81%
35041
55%
**31
96%
Hodgdon H4831
<<locked>>
81%
45963
72%
**15
98%
Hodgdon H4831 SC
<<locked>>
81%
45353
71%
**95
98%
Hodgdon Hybrid 100V
<<locked>>
81%
51982
81%
**41
100%
Hodgdon Retumbo
<<locked>>
81%
36114
57%
**43
98%
Hodgdon TrailBoss
<<locked>>
81%
28863
45%
**81
100%
IMR 4955 Enduron
<<locked>>
81%
47094
74%
**05
98%
IMR 7828 SSC
<<locked>>
81%
42090
66%
**92
98%
[IMR 7977 Enduron]*
<<locked>>
84%
41611
65%
**54
90%
[IMR 8133 Enduron]*
<<locked>>
81%
27035
42%
**47
91%
[Lovex D100]*
<<locked>>
91%
45136
71%
**72
90%
Lovex S071
<<locked>>
81%
38029
60%
**25
99%
[Norma 217]*
<<locked>>
81%
27050
42%
**67
94%
Norma MRP
<<locked>>
81%
46833
73%
**87
100%
Ramshot Grand
<<locked>>
81%
42192
66%
**08
98%
Ramshot Magnum
<<locked>>
81%
37797
59%
**87
98%
ReloadSwiss RS 14
<<locked>>
81%
29515
46%
**17
100%
ReloadSwiss RS 76
<<locked>>
81%
35259
55%
**13
99%
[ReloadSwiss RS 80]*
<<locked>>
81%
32111
50%
**02
92%
Rottweil R 904
<<locked>>
81%
48979
77%
**41
99%
Rottweil R 905
<<locked>>
81%
47703
75%
**51
100%
[SNPE Vectan SP 13]*
<<locked>>
94%
35447
56%
**31
90%
SNPE Vectan Tubal 8000
<<locked>>
81%
47355
74%
**44
99%
[Shooters World 50 BMG]*
<<locked>>
91%
45136
71%
**72
90%
Somchem S361
<<locked>>
81%
49937
78%
**28
99%
Somchem S385
<<locked>>
81%
48283
76%
**31
100%
Vihtavuori N165
<<locked>>
81%
42032
66%
**13
99%
[Vihtavuori N170]*
<<locked>>
82%
37115
58%
**15
90%
Vihtavuori N555
<<locked>>
81%
47543
74%
**31
100%
Vihtavuori N560
<<locked>>
81%
46485
73%
**80
98%
Vihtavuori N565
<<locked>>
81%
38493
60%
**10
96%
[Vihtavuori N568]*
<<locked>>
81%
33475
52%
**21
92%
[Vihtavuori N570]*
<<locked>>
83%
34708
54%
**80
90%
Winchester StaBALL HD
<<locked>>
81%
40669
64%
**08
100%
Winchester Supreme 780
<<locked>>
81%
44425
70%
**66
99%

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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