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Load data for .257 Weath. Mag. + .257 | 120gr | Sierra HPBT GameKing

Recommended Powder(s):

.257 Weath. Mag. + .257 | 120gr | Sierra HPBT GameKing

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.257 | 120gr | Sierra HPBT GameKing
Manufacturer SKU:
1650
Bullet Weight:
120gr | 7.8g
Bullet Diameter:
0.257" | 6.53mm
Bullet Length:
<<locked>>
Caliber:
.257 Weath. Mag. load data
Case Length (l3):
2.549" | 64.7mm
Cartridge Length (C.O.L.):
<<locked>>
Seated Depth:
<<locked>>
Shank Seated Depth:
<<locked>>
Case Capacity:
84.0 Grains of Water | 5.45 cm³
Primer Size:
Large Rifle Magnum (LRM)
Max. allowed Pressure:
63817 psi | 4400 bar
LID:
LID_B5799_C247
Last updated:
2026-01-21
Recommended Twist Rate:
1:10 - 1:9

Load data for 112 loads in caliber .257 Weath. Mag. with .257 | 120gr | Sierra HPBT GameKing bullet and 56 powder(s). 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>>
88%
57043
89%
**14
100%
ADI AR 2213 👍
<<locked>>
91%
56942
89%
**43
99%
ADI AR 2217
<<locked>>
97%
52243
82%
**64
99%
[ADI AR 2218]*
<<locked>>
97%
45397
71%
**82
93%
ADI AR 2225
<<locked>>
97%
46818
73%
**09
100%
Accurate 3100
<<locked>>
90%
56753
89%
**38
100%
Accurate MAGPRO
<<locked>>
90%
56884
89%
**46
98%
Alliant Reloder-16
<<locked>>
84%
57246
90%
**07
100%
Alliant Reloder-19
<<locked>>
88%
57319
90%
**07
100%
Alliant Reloder-22
<<locked>>
91%
57261
90%
**40
100%
Alliant Reloder-23
<<locked>>
92%
57406
90%
**81
100%
Alliant Reloder-25 👍
<<locked>>
96%
56956
89%
**50
100%
Alliant Reloder-26
<<locked>>
87%
57043
89%
**56
100%
Alliant Reloder-33
<<locked>>
97%
49008
77%
**48
95%
Baschieri & Pellagri 109
<<locked>>
92%
57334
90%
**94
97%
Bofors RP15
<<locked>>
93%
57276
90%
**40
100%
Bofors RP30
<<locked>>
97%
55303
87%
**36
99%
Bofors RP5
<<locked>>
91%
57261
90%
**40
100%
Hodgdon H1000
<<locked>>
97%
52243
82%
**64
99%
Hodgdon H4350
<<locked>>
86%
57363
90%
**58
100%
Hodgdon H4831
<<locked>>
93%
57087
89%
**91
99%
Hodgdon H4831 SC
<<locked>>
89%
56652
89%
**87
99%
Hodgdon Hybrid 100V
<<locked>>
86%
57232
90%
**18
100%
Hodgdon Retumbo
<<locked>>
97%
46818
73%
**09
100%
Hodgdon TrailBoss
<<locked>>
97%
35868
56%
**39
100%
IMR 4350
<<locked>>
84%
56869
89%
**51
100%
IMR 4831
<<locked>>
87%
56753
89%
**48
100%
IMR 4955 Enduron
<<locked>>
90%
56927
89%
**64
99%
IMR 7828 SSC 👍
<<locked>>
90%
57101
89%
**59
99%
[IMR 7977 Enduron]*
<<locked>>
95%
56666
89%
**05
93%
IMR 8133 Enduron
<<locked>>
97%
42786
67%
**13
97%
Lovex S071
<<locked>>
95%
56753
89%
**38
100%
Norma 204
<<locked>>
84%
57058
89%
**84
100%
Norma 217
<<locked>>
97%
43540
68%
**43
99%
Norma MRP
<<locked>>
88%
56652
89%
**53
100%
Norma URP
<<locked>>
83%
57261
90%
**64
100%
Ramshot Grand
<<locked>>
87%
57072
89%
**69
99%
Ramshot Hunter
<<locked>>
84%
56826
89%
**84
100%
Ramshot Magnum
<<locked>>
91%
56637
89%
**10
100%
ReloadSwiss RS 14
<<locked>>
96%
36448
57%
**75
100%
ReloadSwiss RS 76 👍
<<locked>>
96%
56840
89%
**28
100%
ReloadSwiss RS 80
<<locked>>
97%
54331
85%
**36
98%
Rottweil R 904
<<locked>>
87%
57232
90%
**74
99%
Rottweil R 905
<<locked>>
88%
57116
90%
**97
100%
Somchem S361
<<locked>>
86%
56913
89%
**28
99%
Somchem S365
<<locked>>
85%
57246
90%
**54
100%
Somchem S385
<<locked>>
88%
57319
90%
**71
100%
Vihtavuori N150
<<locked>>
84%
57406
90%
**72
100%
Vihtavuori N165
<<locked>>
93%
57101
89%
**51
100%
[Vihtavuori N170]*
<<locked>>
97%
48863
77%
**27
93%
Vihtavuori N555
<<locked>>
88%
56608
89%
**74
100%
Vihtavuori N560 👍
<<locked>>
90%
57421
90%
**66
99%
Vihtavuori N565
<<locked>>
94%
56840
89%
**36
99%
Vihtavuori N568
<<locked>>
97%
55477
87%
**63
98%
Vihtavuori N570
<<locked>>
97%
52794
83%
**33
95%
Winchester StaBALL HD
<<locked>>
92%
57377
90%
**82
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2209
<<locked>>
81%
45643
72%
**97
98%
ADI AR 2213
<<locked>>
81%
40872
64%
**25
96%
[ADI AR 2217]*
<<locked>>
81%
30443
48%
**30
90%
[ADI AR 2218]*
<<locked>>
94%
40886
64%
**74
90%
[ADI AR 2225]*
<<locked>>
81%
27717
43%
**93
92%
Accurate 3100
<<locked>>
81%
41524
65%
**59
99%
[Accurate MAGPRO]*
<<locked>>
81%
40567
64%
**18
93%
Alliant Reloder-16
<<locked>>
81%
52359
82%
**28
100%
Alliant Reloder-19
<<locked>>
81%
45629
71%
**94
98%
Alliant Reloder-22
<<locked>>
81%
41394
65%
**38
97%
Alliant Reloder-23
<<locked>>
81%
40118
63%
**85
100%
Alliant Reloder-25
<<locked>>
81%
34650
54%
**03
98%
Alliant Reloder-26
<<locked>>
81%
45295
71%
**53
100%
[Alliant Reloder-33]*
<<locked>>
90%
38464
60%
**12
90%
[Baschieri & Pellagri 109]*
<<locked>>
81%
40118
63%
**36
92%
Bofors RP15
<<locked>>
81%
38624
61%
**72
96%
[Bofors RP30]*
<<locked>>
81%
31981
50%
**12
92%
Bofors RP5
<<locked>>
81%
41394
65%
**38
97%
[Hodgdon H1000]*
<<locked>>
81%
30443
48%
**30
90%
Hodgdon H4350
<<locked>>
81%
49139
77%
**10
99%
[Hodgdon H4831]*
<<locked>>
81%
38247
60%
**13
94%
Hodgdon H4831 SC
<<locked>>
81%
42902
67%
**18
96%
Hodgdon Hybrid 100V
<<locked>>
81%
49516
78%
**97
100%
[Hodgdon Retumbo]*
<<locked>>
81%
27717
43%
**93
92%
Hodgdon TrailBoss
<<locked>>
81%
28616
45%
**75
100%
IMR 4350
<<locked>>
81%
51547
81%
**56
100%
IMR 4831
<<locked>>
81%
47021
74%
**74
100%
IMR 4955 Enduron
<<locked>>
81%
42424
66%
**82
96%
IMR 7828 SSC
<<locked>>
81%
42119
66%
**74
96%
[IMR 7977 Enduron]*
<<locked>>
89%
47050
74%
**31
90%
[IMR 8133 Enduron]*
<<locked>>
86%
29689
47%
**59
90%
Lovex S071
<<locked>>
81%
35723
56%
**25
98%
Norma 204
<<locked>>
81%
52301
82%
**02
99%
[Norma 217]*
<<locked>>
82%
26266
41%
**57
90%
Norma MRP
<<locked>>
81%
43888
69%
**10
99%
Norma URP
<<locked>>
81%
53316
84%
**05
100%
Ramshot Grand
<<locked>>
81%
44382
70%
**23
97%
Ramshot Hunter
<<locked>>
81%
52373
82%
**12
100%
Ramshot Magnum
<<locked>>
81%
38972
61%
**69
97%
ReloadSwiss RS 14
<<locked>>
81%
29225
46%
**14
100%
ReloadSwiss RS 76
<<locked>>
81%
32880
52%
**84
96%
[ReloadSwiss RS 80]*
<<locked>>
83%
32590
51%
**57
90%
Rottweil R 904
<<locked>>
81%
46804
73%
**77
97%
Rottweil R 905
<<locked>>
81%
45049
71%
**81
98%
Somchem S361
<<locked>>
81%
47659
75%
**64
97%
Somchem S365
<<locked>>
81%
50908
80%
**56
100%
Somchem S385
<<locked>>
81%
45716
72%
**58
99%
Vihtavuori N150
<<locked>>
81%
52808
83%
**97
100%
Vihtavuori N165
<<locked>>
81%
38667
61%
**94
97%
[Vihtavuori N170]*
<<locked>>
92%
41872
66%
**76
90%
Vihtavuori N555
<<locked>>
81%
44759
70%
**77
100%
Vihtavuori N560
<<locked>>
81%
41582
65%
**51
95%
[Vihtavuori N565]*
<<locked>>
81%
36143
57%
**00
93%
[Vihtavuori N568]*
<<locked>>
84%
34185
54%
**90
90%
[Vihtavuori N570]*
<<locked>>
89%
39653
62%
**48
90%
Winchester StaBALL HD
<<locked>>
81%
37478
59%
**28
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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