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Load data for .338-378 Weath. Mag. + .338 | 250gr | Lapua Lock Base

Recommended Powder(s): ADI AR 2217, Bofors RP30, Hodgdon H1000, ReloadSwiss RS 76, Vihtavuori N565

.338-378 Weath. Mag. + .338 | 250gr | Lapua Lock Base

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.338 | 250gr | Lapua Lock Base
Manufacturer SKU:
4PL8012 | B408
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_B3197_C472
Last updated:
2026-02-01
Recommended Twist Rate:
1:14 - 1:11

Load data for 108 loads in caliber .338-378 Weath. Mag. with .338 | 250gr | Lapua Lock Base bullet and 54 powders such as ADI AR 2217, Bofors RP30, Hodgdon H1000, ReloadSwiss RS 76, 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%
57334
90%
**12
100%
ADI AR 2213
<<locked>>
88%
57014
89%
**51
100%
ADI AR 2217 👍
<<locked>>
97%
56463
88%
**41
100%
ADI AR 2218
<<locked>>
97%
49037
77%
**15
97%
ADI AR 2225
<<locked>>
97%
51605
81%
**02
100%
Accurate 3100
<<locked>>
88%
57261
90%
**49
100%
[Accurate 8700]*
<<locked>>
97%
39001
61%
**20
92%
Accurate MAGPRO
<<locked>>
88%
56869
89%
**54
99%
Alliant Reloder-19
<<locked>>
86%
57276
90%
**05
100%
Alliant Reloder-22
<<locked>>
88%
56855
89%
**38
100%
Alliant Reloder-23
<<locked>>
89%
57305
90%
**76
100%
Alliant Reloder-25
<<locked>>
93%
57101
89%
**41
100%
Alliant Reloder-26
<<locked>>
85%
57014
89%
**44
100%
Alliant Reloder-33
<<locked>>
97%
54404
85%
**67
98%
Alliant Reloder-50
<<locked>>
97%
46398
73%
**23
95%
Baschieri & Pellagri 109
<<locked>>
90%
57072
89%
**99
98%
Bofors RP15
<<locked>>
91%
57421
90%
**44
100%
Bofors RP30 👍
<<locked>>
95%
56985
89%
**61
100%
Bofors RP5
<<locked>>
88%
56855
89%
**38
100%
Hodgdon H1000 👍
<<locked>>
97%
56463
88%
**41
100%
Hodgdon H4350
<<locked>>
84%
57000
89%
**49
100%
Hodgdon H4831
<<locked>>
91%
57348
90%
**95
100%
Hodgdon H4831 SC
<<locked>>
88%
57348
90%
**95
100%
Hodgdon Hybrid 100V
<<locked>>
83%
57000
89%
**13
100%
Hodgdon Retumbo
<<locked>>
97%
51605
81%
**02
100%
Hodgdon TrailBoss
<<locked>>
96%
35926
56%
**32
100%
IMR 4831
<<locked>>
85%
57203
90%
**40
100%
IMR 4955 Enduron
<<locked>>
89%
57203
90%
**72
100%
IMR 7828 SSC
<<locked>>
87%
57217
90%
**54
100%
IMR 7977 Enduron
<<locked>>
93%
57058
89%
**40
95%
IMR 8133 Enduron
<<locked>>
97%
47253
74%
**17
99%
[Lovex D100]*
<<locked>>
97%
56188
88%
**59
94%
Lovex S071
<<locked>>
93%
57261
90%
**49
100%
Norma 217
<<locked>>
97%
48066
75%
**46
100%
Norma MRP
<<locked>>
86%
57363
90%
**48
100%
Ramshot Grand
<<locked>>
85%
57276
90%
**67
100%
Ramshot Magnum
<<locked>>
88%
56826
89%
**08
100%
ReloadSwiss RS 14
<<locked>>
97%
37144
58%
**75
100%
ReloadSwiss RS 76 👍
<<locked>>
93%
57130
90%
**13
100%
ReloadSwiss RS 80
<<locked>>
96%
57392
90%
**07
100%
Rottweil R 904
<<locked>>
85%
57087
89%
**72
100%
Rottweil R 905
<<locked>>
86%
57290
90%
**08
100%
[SNPE Vectan SP 13]*
<<locked>>
97%
41118
64%
**52
93%
[Shooters World 50 BMG]*
<<locked>>
97%
56188
88%
**59
94%
Somchem S361
<<locked>>
85%
57334
90%
**46
100%
Somchem S385
<<locked>>
86%
57000
89%
**62
100%
Vihtavuori N165
<<locked>>
91%
57014
89%
**56
100%
Vihtavuori N170
<<locked>>
97%
52431
82%
**17
96%
Vihtavuori N555
<<locked>>
86%
56985
89%
**72
100%
Vihtavuori N560
<<locked>>
88%
56985
89%
**64
100%
Vihtavuori N565 👍
<<locked>>
92%
57348
90%
**44
100%
Vihtavuori N568
<<locked>>
95%
57116
90%
**90
99%
Vihtavuori N570
<<locked>>
96%
57101
89%
**23
98%
Winchester StaBALL HD
<<locked>>
89%
57159
90%
**61
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2209
<<locked>>
81%
49139
77%
**90
100%
ADI AR 2213
<<locked>>
81%
44251
69%
**28
98%
ADI AR 2217
<<locked>>
81%
32938
52%
**79
95%
[ADI AR 2218]*
<<locked>>
88%
35665
56%
**00
90%
ADI AR 2225
<<locked>>
81%
30139
47%
**43
97%
Accurate 3100
<<locked>>
81%
44889
70%
**59
100%
[Accurate 8700]*
<<locked>>
94%
35607
56%
**44
90%
Accurate MAGPRO
<<locked>>
81%
44251
69%
**41
97%
Alliant Reloder-19
<<locked>>
81%
48965
77%
**74
100%
Alliant Reloder-22
<<locked>>
81%
44918
70%
**38
99%
Alliant Reloder-23
<<locked>>
81%
43656
68%
**75
100%
Alliant Reloder-25
<<locked>>
81%
37724
59%
**13
100%
Alliant Reloder-26
<<locked>>
81%
49574
78%
**40
100%
[Alliant Reloder-33]*
<<locked>>
84%
33489
52%
**38
90%
[Alliant Reloder-50]*
<<locked>>
89%
34998
55%
**77
90%
Baschieri & Pellagri 109
<<locked>>
81%
42772
67%
**46
95%
Bofors RP15
<<locked>>
81%
41887
66%
**75
99%
Bofors RP30
<<locked>>
81%
35230
55%
**54
96%
Bofors RP5
<<locked>>
81%
44918
70%
**38
99%
Hodgdon H1000
<<locked>>
81%
32938
52%
**79
95%
Hodgdon H4350
<<locked>>
81%
52170
82%
**80
100%
Hodgdon H4831
<<locked>>
81%
41249
65%
**20
97%
Hodgdon H4831 SC
<<locked>>
81%
46195
72%
**12
98%
Hodgdon Hybrid 100V
<<locked>>
81%
53069
83%
**57
100%
Hodgdon Retumbo
<<locked>>
81%
30139
47%
**43
97%
Hodgdon TrailBoss
<<locked>>
87%
31734
50%
**50
100%
IMR 4831
<<locked>>
81%
50502
79%
**48
100%
IMR 4955 Enduron
<<locked>>
81%
45150
71%
**72
98%
IMR 7828 SSC
<<locked>>
81%
45716
72%
**71
99%
[IMR 7977 Enduron]*
<<locked>>
83%
41191
65%
**54
90%
[IMR 8133 Enduron]*
<<locked>>
81%
27601
43%
**64
91%
[Lovex D100]*
<<locked>>
91%
44759
70%
**66
90%
Lovex S071
<<locked>>
81%
38696
61%
**38
100%
[Norma 217]*
<<locked>>
81%
27644
43%
**87
94%
Norma MRP
<<locked>>
81%
47732
75%
**03
100%
Ramshot Grand
<<locked>>
81%
48501
76%
**26
99%
Ramshot Magnum
<<locked>>
81%
42656
67%
**79
99%
ReloadSwiss RS 14
<<locked>>
83%
30690
48%
**47
100%
ReloadSwiss RS 76
<<locked>>
81%
36129
57%
**33
99%
[ReloadSwiss RS 80]*
<<locked>>
81%
33011
52%
**28
93%
Rottweil R 904
<<locked>>
81%
49893
78%
**61
99%
Rottweil R 905
<<locked>>
81%
48675
76%
**71
100%
[SNPE Vectan SP 13]*
<<locked>>
93%
35549
56%
**28
90%
[Shooters World 50 BMG]*
<<locked>>
91%
44759
70%
**66
90%
Somchem S361
<<locked>>
81%
50923
80%
**48
99%
Somchem S385
<<locked>>
81%
49168
77%
**48
100%
Vihtavuori N165
<<locked>>
81%
41713
65%
**03
99%
[Vihtavuori N170]*
<<locked>>
85%
36477
57%
**08
90%
Vihtavuori N555
<<locked>>
81%
48501
76%
**48
100%
Vihtavuori N560
<<locked>>
81%
45049
71%
**51
98%
Vihtavuori N565
<<locked>>
81%
39305
62%
**26
97%
[Vihtavuori N568]*
<<locked>>
81%
34200
54%
**41
93%
[Vihtavuori N570]*
<<locked>>
82%
34360
54%
**67
90%
Winchester StaBALL HD
<<locked>>
81%
42032
66%
**38
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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