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Load data for .338-378 Weath. Mag. + .338 | 250gr | A-Square MONO RN

Recommended Powder(s): ADI AR 2217, ADI AR 2225, Hodgdon Retumbo, ReloadSwiss RS 80, Vihtavuori N568

.338-378 Weath. Mag. + .338 | 250gr | A-Square MONO RN

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.338 | 250gr | A-Square MONO RN
Bullet Weight:
250gr | 16.2g
Bullet Diameter:
0.338" | 8.59mm
Bullet Length:
1.000" | 25.4mm
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:
0.216" | 5.5mm
Shank Seated Depth:
0.216" | 5.5mm
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_B384_C472
Last updated:
2025-09-18

Load data for 92 loads in caliber .338-378 Weath. Mag. with .338 | 250gr | A-Square MONO RN bullet and 46 powders such as ADI AR 2217, ADI AR 2225, Hodgdon Retumbo, ReloadSwiss RS 80, 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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  • 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>>
83%
57261
90%
**18
100%
ADI AR 2213
<<locked>>
86%
57363
90%
**51
100%
ADI AR 2217 👍
<<locked>>
94%
56898
89%
**51
100%
ADI AR 2218
<<locked>>
97%
54578
86%
**23
98%
ADI AR 2225 👍
<<locked>>
97%
57043
89%
**77
100%
Accurate 3100
<<locked>>
86%
57203
90%
**53
100%
Accurate 8700
<<locked>>
97%
43294
68%
**18
95%
Accurate MAGPRO
<<locked>>
86%
57029
89%
**58
99%
Alliant Reloder-19
<<locked>>
84%
57145
90%
**12
100%
Alliant Reloder-22
<<locked>>
86%
57348
90%
**48
100%
Alliant Reloder-23
<<locked>>
87%
57290
90%
**76
100%
Alliant Reloder-25
<<locked>>
90%
57000
89%
**38
100%
Alliant Reloder-33
<<locked>>
95%
57087
89%
**10
99%
Alliant Reloder-50
<<locked>>
97%
52402
82%
**28
97%
Hodgdon H1000
<<locked>>
94%
56898
89%
**51
100%
Hodgdon H4831
<<locked>>
89%
57087
89%
**08
100%
Hodgdon H4831 SC
<<locked>>
85%
57305
90%
**05
100%
Hodgdon Retumbo 👍
<<locked>>
97%
57043
89%
**77
100%
Hodgdon TrailBoss
<<locked>>
97%
36376
57%
**62
100%
IMR 4955 Enduron
<<locked>>
86%
57305
90%
**79
100%
IMR 7828 SSC
<<locked>>
85%
57029
89%
**54
100%
IMR 7977 Enduron
<<locked>>
91%
57130
90%
**56
96%
IMR 8133 Enduron
<<locked>>
97%
52417
82%
**02
100%
Lovex D100
<<locked>>
95%
57232
90%
**85
95%
Lovex S071
<<locked>>
91%
56956
89%
**46
100%
Norma 217
<<locked>>
97%
53998
85%
**35
100%
Norma MRP
<<locked>>
84%
57261
90%
**54
100%
[Ramshot LRT]*
<<locked>>
97%
54288
85%
**41
93%
Ramshot Magnum
<<locked>>
86%
57377
90%
**15
100%
ReloadSwiss RS 14
<<locked>>
97%
37362
59%
**04
100%
ReloadSwiss RS 76
<<locked>>
90%
57188
90%
**07
100%
ReloadSwiss RS 80 👍
<<locked>>
93%
57130
90%
**90
100%
Rottweil R 904
<<locked>>
83%
57087
89%
**82
100%
Rottweil R 905
<<locked>>
84%
57072
89%
**05
100%
SNPE Vectan SP 13
<<locked>>
97%
45513
71%
**41
95%
Somchem S385
<<locked>>
83%
57246
90%
**76
100%
[Vihtavuori 20N29]*
<<locked>>
97%
43323
68%
**08
92%
[Vihtavuori 24N41]*
<<locked>>
97%
54795
86%
**18
93%
Vihtavuori N165
<<locked>>
88%
57246
90%
**59
100%
Vihtavuori N170
<<locked>>
97%
57232
90%
**95
97%
Vihtavuori N555
<<locked>>
84%
57276
90%
**76
100%
Vihtavuori N560
<<locked>>
85%
57130
90%
**64
100%
Vihtavuori N565
<<locked>>
89%
57406
90%
**48
100%
Vihtavuori N568 👍
<<locked>>
93%
57435
90%
**97
100%
Vihtavuori N570
<<locked>>
94%
57319
90%
**23
98%
Winchester StaBALL HD
<<locked>>
86%
56927
89%
**48
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2209
<<locked>>
81%
53127
83%
**59
100%
ADI AR 2213
<<locked>>
81%
48153
75%
**03
99%
ADI AR 2217
<<locked>>
81%
35897
56%
**51
96%
[ADI AR 2218]*
<<locked>>
85%
34940
55%
**80
90%
ADI AR 2225
<<locked>>
81%
33199
52%
**31
98%
Accurate 3100
<<locked>>
81%
48762
76%
**28
100%
[Accurate 8700]*
<<locked>>
90%
34272
54%
**11
90%
Accurate MAGPRO
<<locked>>
81%
48269
76%
**17
98%
Alliant Reloder-19
<<locked>>
81%
52750
83%
**49
100%
Alliant Reloder-22
<<locked>>
81%
48834
77%
**07
100%
Alliant Reloder-23
<<locked>>
81%
47485
74%
**35
100%
Alliant Reloder-25
<<locked>>
81%
41698
65%
**95
100%
[Alliant Reloder-33]*
<<locked>>
81%
33518
53%
**28
90%
[Alliant Reloder-50]*
<<locked>>
85%
34142
54%
**44
90%
Hodgdon H1000
<<locked>>
81%
35897
56%
**51
96%
Hodgdon H4831
<<locked>>
81%
44686
70%
**95
98%
Hodgdon H4831 SC
<<locked>>
81%
49647
78%
**87
99%
Hodgdon Retumbo
<<locked>>
81%
33199
52%
**31
98%
Hodgdon TrailBoss
<<locked>>
85%
30661
48%
**47
100%
IMR 4955 Enduron
<<locked>>
81%
48399
76%
**38
99%
IMR 7828 SSC
<<locked>>
81%
50111
79%
**46
99%
[IMR 7977 Enduron]*
<<locked>>
81%
41089
64%
**64
91%
[IMR 8133 Enduron]*
<<locked>>
81%
30661
48%
**52
94%
[Lovex D100]*
<<locked>>
87%
43555
68%
**49
90%
Lovex S071
<<locked>>
81%
41989
66%
**03
100%
Norma 217
<<locked>>
81%
31024
49%
**69
96%
Norma MRP
<<locked>>
81%
52214
82%
**76
100%
[Ramshot LRT]*
<<locked>>
92%
45440
71%
**77
90%
Ramshot Magnum
<<locked>>
81%
47137
74%
**61
100%
ReloadSwiss RS 14
<<locked>>
81%
29921
47%
**50
100%
ReloadSwiss RS 76
<<locked>>
81%
40205
63%
**21
100%
ReloadSwiss RS 80
<<locked>>
81%
36912
58%
**13
95%
Rottweil R 904
<<locked>>
81%
53490
84%
**23
100%
Rottweil R 905
<<locked>>
81%
52504
82%
**33
100%
[SNPE Vectan SP 13]*
<<locked>>
89%
34650
54%
**05
90%
Somchem S385
<<locked>>
81%
52750
83%
**07
100%
[Vihtavuori 20N29]*
<<locked>>
94%
39421
62%
**26
90%
[Vihtavuori 24N41]*
<<locked>>
92%
45745
72%
**51
90%
Vihtavuori N165
<<locked>>
81%
45107
71%
**69
100%
[Vihtavuori N170]*
<<locked>>
82%
35549
56%
**88
90%
Vihtavuori N555
<<locked>>
81%
52576
82%
**10
100%
Vihtavuori N560
<<locked>>
81%
49211
77%
**33
99%
Vihtavuori N565
<<locked>>
81%
43323
68%
**98
98%
Vihtavuori N568
<<locked>>
81%
37985
60%
**23
95%
[Vihtavuori N570]*
<<locked>>
81%
36463
57%
**16
92%
Winchester StaBALL HD
<<locked>>
81%
47094
74%
**03
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.

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

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