top of page

Load data for .256 Mag. Gibbs + .257 | 100gr | Sierra SPT Pro-Hunter

Recommended Powder(s): Accurate No. 11 FS

.256 Mag. Gibbs + .257 | 100gr | Sierra SPT Pro-Hunter

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.257 | 100gr | Sierra SPT Pro-Hunter
Manufacturer SKU:
1620
Bullet Weight:
100gr | 6.5g
Bullet Diameter:
0.257" | 6.53mm
Bullet Length:
0.961" | 24.4mm
Caliber:
.256 Mag. Gibbs load data
Case Length (l3):
2.173" | 55.2mm
Cartridge Length (C.O.L.):
3.004" | 76.3mm
Seated Depth:
0.130" | 3.3mm
Shank Seated Depth:
0.130" | 3.3mm
Case Capacity:
56.0 Grains of Water | 3.64 cm³
Primer Size:
Large Rifle (LR)
Max. allowed Pressure:
49313 psi | 3400 bar
LID:
LID_B5794_C231
Last updated:
2025-02-02

Load data for 136 loads in caliber .256 Mag. Gibbs with .257 | 100gr | Sierra SPT Pro-Hunter bullet and 68 powders such as Accurate No. 11 FS. 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".

  • Muzzle velocity vs. barrel length

    Every 1 inch additional barrel length increases muzzle velocity by approx. 20.9 fps

  • .

    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.

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 2208
<<locked>>
87%
48689
99%
**86
99%
[ADI AR 2209]*
<<locked>>
96%
45527
92%
**76
92%
Accurate 2700
<<locked>>
87%
48443
98%
**10
95%
[Accurate 3100]*
<<locked>>
96%
38203
77%
**12
94%
Accurate 4064
<<locked>>
85%
48341
98%
**82
100%
Accurate 4350
<<locked>>
94%
48878
99%
**64
98%
Alliant Reloder- TS 15.5
<<locked>>
86%
48428
98%
**02
100%
Alliant Reloder-15
<<locked>>
85%
49139
100%
**31
99%
Alliant Reloder-16 👍
<<locked>>
95%
48921
99%
**04
99%
Alliant Reloder-17 👍
<<locked>>
91%
48805
99%
**23
100%
[Alliant Reloder-19]*
<<locked>>
96%
44744
91%
**59
92%
Alliant Reloder-23
<<locked>>
97%
37014
75%
**54
97%
Alliant Reloder-26
<<locked>>
97%
41495
84%
**12
96%
Hodgdon CFE223
<<locked>>
85%
49197
100%
**58
99%
Hodgdon H380
<<locked>>
86%
49124
100%
**12
98%
Hodgdon H414
<<locked>>
90%
49168
100%
**71
96%
Hodgdon H4350
<<locked>>
96%
48979
99%
**92
95%
Hodgdon Hybrid 100V
<<locked>>
97%
48327
98%
**25
100%
Hodgdon LVR
<<locked>>
92%
48544
98%
**45
98%
Hodgdon Superperformance
<<locked>>
92%
48631
99%
**74
95%
Hodgdon VARGET
<<locked>>
87%
49226
100%
**95
99%
Hodgdon TrailBoss
<<locked>>
96%
33765
68%
**06
100%
IMR 3031
<<locked>>
84%
48341
98%
**99
100%
IMR 4064
<<locked>>
87%
48675
99%
**76
99%
IMR 4166 Enduron
<<locked>>
88%
48356
98%
**36
96%
IMR 4350
<<locked>>
94%
48530
98%
**82
95%
IMR 4451 Enduron
<<locked>>
89%
48863
99%
**72
96%
IMR 4831
<<locked>>
97%
45208
92%
**69
98%
IMR 4895
<<locked>>
84%
48428
98%
**25
99%
Lovex S062
<<locked>>
85%
48428
98%
**79
100%
Lovex S065
<<locked>>
92%
49081
100%
**89
97%
Lovex S070
<<locked>>
93%
48689
99%
**02
96%
Norma 203B
<<locked>>
85%
48486
98%
**18
99%
[Norma 204]*
<<locked>>
94%
48863
99%
**31
93%
[Norma MRP]*
<<locked>>
97%
41481
84%
**72
93%
Norma URP
<<locked>>
94%
48602
99%
**51
98%
Ramshot Big Game
<<locked>>
85%
48167
98%
**25
99%
Ramshot Hunter
<<locked>>
95%
48211
98%
**58
97%
ReloadSwiss RS 14
<<locked>>
97%
34664
70%
**59
100%
ReloadSwiss RS 50
<<locked>>
86%
48414
98%
**79
96%
ReloadSwiss RS 52
<<locked>>
85%
48457
98%
**45
100%
ReloadSwiss RS 60 👍
<<locked>>
92%
49197
100%
**43
100%
ReloadSwiss RS 62
<<locked>>
94%
48356
98%
**74
98%
ReloadSwiss RS 70
<<locked>>
94%
49008
99%
**17
98%
Rottweil R 902
<<locked>>
84%
49139
100%
**66
100%
Rottweil R 903
<<locked>>
89%
48617
99%
**05
100%
[Rottweil R 904]*
<<locked>>
97%
47297
96%
**56
92%
[Rottweil R 905]*
<<locked>>
97%
43424
88%
**49
92%
Rottweil R 907
<<locked>>
90%
48892
99%
**72
95%
SNPE Vectan SP 11
<<locked>>
87%
48370
98%
**38
99%
SNPE Vectan Tubal 5000
<<locked>>
87%
49110
100%
**94
100%
SNPE Vectan Tubal 7000
<<locked>>
91%
48370
98%
**17
96%
Shooters World Long Rifle
<<locked>>
92%
49081
100%
**89
97%
Shooters World Precision
<<locked>>
85%
48428
98%
**79
100%
Somchem S355
<<locked>>
89%
49095
100%
**12
100%
Somchem S365 👍
<<locked>>
96%
47108
96%
**64
100%
[Somchem S385]*
<<locked>>
97%
44686
91%
**46
94%
Vihtavuori N133
<<locked>>
84%
49037
99%
**87
100%
Vihtavuori N135
<<locked>>
90%
49153
100%
**53
100%
Vihtavuori N140
<<locked>>
84%
49139
100%
**53
100%
Vihtavuori N150
<<locked>>
93%
48718
99%
**69
100%
Vihtavuori N160
<<locked>>
92%
49226
100%
**22
98%
Vihtavuori N540
<<locked>>
84%
48834
99%
**72
100%
Vihtavuori N550
<<locked>>
91%
48472
98%
**54
98%
Vihtavuori N555
<<locked>>
97%
40756
83%
**46
97%
Winchester 6.5 StaBALL 👍
<<locked>>
93%
49240
100%
**99
100%
Winchester 760
<<locked>>
90%
49168
100%
**71
96%
Winchester StaBALL HD
<<locked>>
96%
32793
66%
**12
96%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2208
<<locked>>
81%
40727
83%
**22
97%
[ADI AR 2209]*
<<locked>>
93%
40277
82%
**58
90%
[Accurate 2700]*
<<locked>>
81%
39015
79%
**17
91%
[Accurate 3100]*
<<locked>>
91%
31459
64%
**38
90%
Accurate 4064
<<locked>>
81%
42047
85%
**58
100%
[Accurate 4350]*
<<locked>>
81%
31038
63%
**48
93%
Alliant Reloder- TS 15.5
<<locked>>
81%
40422
82%
**38
98%
Alliant Reloder-15
<<locked>>
81%
43555
88%
**13
98%
[Alliant Reloder-16]*
<<locked>>
81%
31459
64%
**67
93%
Alliant Reloder-17
<<locked>>
81%
35273
72%
**05
97%
[Alliant Reloder-19]*
<<locked>>
93%
39827
81%
**54
90%
[Alliant Reloder-23]*
<<locked>>
85%
25483
52%
**77
90%
[Alliant Reloder-26]*
<<locked>>
88%
30661
62%
**97
90%
Hodgdon CFE223
<<locked>>
81%
41959
85%
**13
97%
Hodgdon H380
<<locked>>
81%
40988
83%
**51
96%
[Hodgdon H414]*
<<locked>>
81%
36318
74%
**82
91%
[Hodgdon H4350]*
<<locked>>
86%
35766
73%
**07
90%
[Hodgdon Hybrid 100V]*
<<locked>>
81%
28718
58%
**52
93%
[Hodgdon LVR]*
<<locked>>
81%
34127
69%
**17
93%
[Hodgdon Superperformance]*
<<locked>>
84%
36811
75%
**99
90%
Hodgdon VARGET
<<locked>>
81%
40364
82%
**15
97%
Hodgdon TrailBoss
<<locked>>
81%
27151
55%
**55
100%
IMR 3031
<<locked>>
81%
44469
90%
**30
100%
IMR 4064
<<locked>>
81%
39914
81%
**99
97%
[IMR 4166 Enduron]*
<<locked>>
81%
39929
81%
**56
93%
[IMR 4350]*
<<locked>>
84%
35375
72%
**94
90%
[IMR 4451 Enduron]*
<<locked>>
81%
37884
77%
**40
92%
[IMR 4831]*
<<locked>>
81%
27412
56%
**23
90%
IMR 4895
<<locked>>
81%
44701
91%
**53
99%
Lovex S062
<<locked>>
81%
42975
87%
**71
99%
[Lovex S065]*
<<locked>>
81%
35128
71%
**77
93%
[Lovex S070]*
<<locked>>
81%
33257
67%
**41
90%
Norma 203B
<<locked>>
81%
43062
87%
**04
98%
[Norma 204]*
<<locked>>
88%
39885
81%
**38
90%
[Norma MRP]*
<<locked>>
93%
36056
73%
**25
90%
[Norma URP]*
<<locked>>
81%
31488
64%
**54
92%
Ramshot Big Game
<<locked>>
81%
42569
86%
**10
98%
[Ramshot Hunter]*
<<locked>>
82%
31850
65%
**64
90%
ReloadSwiss RS 14
<<locked>>
81%
27253
55%
**88
100%
[ReloadSwiss RS 50]*
<<locked>>
81%
41408
84%
**28
94%
ReloadSwiss RS 52
<<locked>>
81%
41771
85%
**17
99%
ReloadSwiss RS 60
<<locked>>
81%
34287
70%
**95
97%
[ReloadSwiss RS 62]*
<<locked>>
81%
30777
62%
**54
92%
[ReloadSwiss RS 70]*
<<locked>>
82%
31633
64%
**74
91%
Rottweil R 902
<<locked>>
81%
44556
90%
**84
99%
Rottweil R 903
<<locked>>
81%
37826
77%
**89
98%
[Rottweil R 904]*
<<locked>>
94%
43729
89%
**90
90%
[Rottweil R 905]*
<<locked>>
93%
38493
78%
**31
90%
[Rottweil R 907]*
<<locked>>
81%
36216
73%
**90
90%
SNPE Vectan SP 11
<<locked>>
81%
38885
79%
**41
97%
SNPE Vectan Tubal 5000
<<locked>>
81%
40045
81%
**33
100%
[SNPE Vectan Tubal 7000]*
<<locked>>
81%
34171
69%
**12
91%
[Shooters World Long Rifle]*
<<locked>>
81%
35128
71%
**77
93%
Shooters World Precision
<<locked>>
81%
42975
87%
**71
99%
Somchem S355
<<locked>>
81%
38653
78%
**95
98%
Somchem S365
<<locked>>
81%
27978
57%
**89
95%
[Somchem S385]*
<<locked>>
91%
36463
74%
**53
90%
Vihtavuori N133
<<locked>>
81%
45281
92%
**28
100%
Vihtavuori N135
<<locked>>
81%
37449
76%
**26
100%
Vihtavuori N140
<<locked>>
81%
44353
90%
**64
100%
Vihtavuori N150
<<locked>>
81%
33025
67%
**28
97%
[Vihtavuori N160]*
<<locked>>
81%
34026
69%
**87
94%
Vihtavuori N540
<<locked>>
81%
44135
89%
**90
100%
[Vihtavuori N550]*
<<locked>>
81%
34476
70%
**33
94%
[Vihtavuori N555]*
<<locked>>
84%
26252
53%
**30
90%
Winchester 6.5 StaBALL
<<locked>>
81%
32793
67%
**41
96%
[Winchester 760]*
<<locked>>
81%
36318
74%
**82
91%
[Winchester StaBALL HD]*
<<locked>>
90%
26498
54%
**62
90%

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.

bottom of page