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Load data for .338-378 Weath. Mag. + .338 | 250gr | Barnes MRX BT

Recommended Powder(s): ADI AR 2217, Hodgdon H1000, ReloadSwiss RS 76, ReloadSwiss RS 80, Vihtavuori N565

.338-378 Weath. Mag. + .338 | 250gr | Barnes MRX BT

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.338 | 250gr | Barnes MRX BT
Manufacturer SKU:
33869
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_B680_C472
Last updated:
2025-09-18
Recommended Twist Rate:
1:14 - 1:11

Load data for 0 loads in caliber .338-378 Weath. Mag. with .338 | 250gr | Barnes MRX BT bullet and 0 powders such as ADI AR 2217, Hodgdon H1000, ReloadSwiss RS 76, ReloadSwiss RS 80, 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%
57217
90%
**15
100%
ADI AR 2213
<<locked>>
89%
56913
89%
**51
100%
ADI AR 2217
<<locked>>
97%
54984
86%
**18
100%
ADI AR 2218
<<locked>>
97%
47311
74%
**72
96%
ADI AR 2225
<<locked>>
97%
49661
78%
**76
100%
Accurate 3100
<<locked>>
89%
57087
89%
**49
100%
Accurate MAGPRO
<<locked>>
89%
57217
90%
**61
99%
Alliant Reloder-19
<<locked>>
86%
56942
89%
**05
100%
Alliant Reloder-22
<<locked>>
89%
57319
90%
**44
100%
Alliant Reloder-23
<<locked>>
90%
57406
90%
**76
100%
Alliant Reloder-25
<<locked>>
94%
57188
90%
**48
100%
Alliant Reloder-26
<<locked>>
86%
57261
90%
**51
100%
Alliant Reloder-33
<<locked>>
97%
52417
82%
**35
97%
Alliant Reloder-50
<<locked>>
97%
44266
69%
**87
95%
Baschieri & Pellagri 109
<<locked>>
91%
57246
90%
**12
98%
Bofors RP15 👍
<<locked>>
92%
57392
90%
**38
100%
Bofors RP30 👍
<<locked>>
96%
57421
90%
**64
100%
Bofors RP5
<<locked>>
89%
57319
90%
**44
100%
Hodgdon H1000
<<locked>>
97%
54984
86%
**18
100%
Hodgdon H4350
<<locked>>
85%
57217
90%
**56
100%
Hodgdon H4831
<<locked>>
92%
57029
89%
**95
100%
Hodgdon H4831 SC
<<locked>>
88%
57363
90%
**08
100%
Hodgdon Hybrid 100V
<<locked>>
84%
57246
90%
**17
100%
Hodgdon Retumbo
<<locked>>
97%
49661
78%
**76
100%
Hodgdon TrailBoss
<<locked>>
96%
35839
56%
**29
100%
IMR 4831
<<locked>>
86%
57232
90%
**46
100%
IMR 4955 Enduron
<<locked>>
89%
57421
90%
**72
100%
IMR 7828 SSC
<<locked>>
88%
56971
89%
**58
100%
IMR 7977 Enduron
<<locked>>
94%
56985
89%
**33
95%
IMR 8133 Enduron
<<locked>>
97%
45672
72%
**94
99%
[Lovex D100]*
<<locked>>
97%
54346
85%
**36
93%
Lovex S071
<<locked>>
94%
57087
89%
**49
100%
Norma 217
<<locked>>
97%
46267
73%
**20
100%
Norma MRP
<<locked>>
87%
57348
90%
**54
100%
Ramshot Grand
<<locked>>
86%
56840
89%
**58
100%
Ramshot Magnum
<<locked>>
89%
57000
89%
**12
100%
ReloadSwiss RS 14
<<locked>>
97%
37014
58%
**75
100%
ReloadSwiss RS 76 👍
<<locked>>
94%
56942
89%
**20
100%
ReloadSwiss RS 80 👍
<<locked>>
96%
57145
90%
**94
100%
Rottweil R 904
<<locked>>
86%
57334
90%
**72
100%
Rottweil R 905
<<locked>>
87%
56927
89%
**99
100%
[SNPE Vectan SP 13]*
<<locked>>
97%
39218
61%
**10
92%
[Shooters World 50 BMG]*
<<locked>>
97%
54346
85%
**36
93%
Somchem S361
<<locked>>
85%
57014
89%
**46
100%
Somchem S365
<<locked>>
83%
57377
90%
**53
100%
Somchem S385
<<locked>>
87%
57232
90%
**69
100%
Vihtavuori N165
<<locked>>
92%
57130
90%
**53
100%
Vihtavuori N170
<<locked>>
97%
50981
80%
**97
95%
Vihtavuori N555
<<locked>>
87%
57000
89%
**76
100%
Vihtavuori N560
<<locked>>
89%
57087
89%
**61
100%
Vihtavuori N565 👍
<<locked>>
93%
57203
90%
**48
100%
Vihtavuori N568
<<locked>>
96%
57087
89%
**87
99%
Vihtavuori N570
<<locked>>
97%
56188
88%
**10
98%
Winchester StaBALL HD
<<locked>>
90%
57203
90%
**61
100%
Winchester Supreme 780
<<locked>>
86%
57145
90%
**72
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2209
<<locked>>
81%
47863
75%
**61
99%
ADI AR 2213
<<locked>>
81%
42728
67%
**08
98%
[ADI AR 2217]*
<<locked>>
81%
31705
50%
**46
94%
[ADI AR 2218]*
<<locked>>
89%
36027
56%
**10
90%
ADI AR 2225
<<locked>>
81%
28761
45%
**06
96%
Accurate 3100
<<locked>>
81%
43076
67%
**26
100%
Accurate MAGPRO
<<locked>>
81%
42598
67%
**02
96%
Alliant Reloder-19
<<locked>>
81%
47616
75%
**54
99%
Alliant Reloder-22
<<locked>>
81%
43279
68%
**02
99%
Alliant Reloder-23
<<locked>>
81%
42032
66%
**49
100%
Alliant Reloder-25
<<locked>>
81%
36405
57%
**87
100%
Alliant Reloder-26
<<locked>>
81%
47674
75%
**17
100%
[Alliant Reloder-33]*
<<locked>>
85%
33765
53%
**44
90%
[Alliant Reloder-50]*
<<locked>>
91%
35056
55%
**80
90%
[Baschieri & Pellagri 109]*
<<locked>>
81%
41539
65%
**20
94%
Bofors RP15
<<locked>>
81%
40422
63%
**46
98%
Bofors RP30
<<locked>>
81%
33605
53%
**11
95%
Bofors RP5
<<locked>>
81%
43279
68%
**02
99%
[Hodgdon H1000]*
<<locked>>
81%
31705
50%
**46
94%
Hodgdon H4350
<<locked>>
81%
51024
80%
**57
100%
Hodgdon H4831
<<locked>>
81%
40030
63%
**97
96%
Hodgdon H4831 SC
<<locked>>
81%
44585
70%
**92
98%
Hodgdon Hybrid 100V
<<locked>>
81%
51605
81%
**44
100%
Hodgdon Retumbo
<<locked>>
81%
28761
45%
**06
96%
Hodgdon TrailBoss
<<locked>>
81%
28660
45%
**85
100%
IMR 4831
<<locked>>
81%
49081
77%
**31
100%
IMR 4955 Enduron
<<locked>>
81%
43947
69%
**43
98%
IMR 7828 SSC
<<locked>>
81%
44237
69%
**44
98%
[IMR 7977 Enduron]*
<<locked>>
84%
41452
65%
**61
90%
[IMR 8133 Enduron]*
<<locked>>
81%
26397
41%
**34
90%
[Lovex D100]*
<<locked>>
92%
45527
71%
**82
90%
Lovex S071
<<locked>>
81%
37057
58%
**11
99%
[Norma 217]*
<<locked>>
81%
26179
41%
**41
93%
Norma MRP
<<locked>>
81%
46195
72%
**77
100%
Ramshot Grand
<<locked>>
81%
46963
74%
**03
99%
Ramshot Magnum
<<locked>>
81%
41162
64%
**52
99%
ReloadSwiss RS 14
<<locked>>
81%
29443
46%
**21
100%
ReloadSwiss RS 76
<<locked>>
81%
34650
54%
**03
99%
[ReloadSwiss RS 80]*
<<locked>>
81%
31328
49%
**82
92%
Rottweil R 904
<<locked>>
81%
48747
76%
**35
99%
Rottweil R 905
<<locked>>
81%
47268
74%
**51
100%
[SNPE Vectan SP 13]*
<<locked>>
94%
35636
56%
**34
90%
[Shooters World 50 BMG]*
<<locked>>
92%
45527
71%
**82
90%
Somchem S361
<<locked>>
81%
49603
78%
**31
99%
Somchem S365
<<locked>>
81%
53301
84%
**94
100%
Somchem S385
<<locked>>
81%
47456
74%
**18
100%
Vihtavuori N165
<<locked>>
81%
40277
63%
**77
99%
[Vihtavuori N170]*
<<locked>>
87%
37101
58%
**21
90%
Vihtavuori N555
<<locked>>
81%
46586
73%
**25
100%
Vihtavuori N560
<<locked>>
81%
43700
68%
**28
98%
Vihtavuori N565
<<locked>>
81%
37753
59%
**90
96%
[Vihtavuori N568]*
<<locked>>
81%
32779
51%
**11
92%
[Vihtavuori N570]*
<<locked>>
84%
34751
54%
**77
90%
Winchester StaBALL HD
<<locked>>
81%
39885
62%
**02
100%
Winchester Supreme 780
<<locked>>
81%
47790
75%
**25
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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