top of page

Load data for .256 Mag. Gibbs + .257 | 100gr | Sierra HPBT MatchKing

Recommended Powder(s):

.256 Mag. Gibbs + .257 | 100gr | Sierra HPBT MatchKing

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.257 | 100gr | Sierra MatchKing
Manufacturer SKU:
1628
Bullet Weight:
100gr | 6.5g
Bullet Diameter:
0.257" | 6.53mm
Bullet Length:
<<locked>>
Caliber:
.256 Mag. Gibbs load data
Case Length (l3):
2.173" | 55.2mm
Cartridge Length (C.O.L.):
<<locked>>
Seated Depth:
<<locked>>
Shank Seated Depth:
<<locked>>
Case Capacity:
56.0 Grains of Water | 3.64 cm³
Primer Size:
Large Rifle (LR)
Max. allowed Pressure:
49313 psi | 3400 bar
LID:
LID_B5792_C231
Last updated:
2026-03-22
Recommended Twist Rate:
1:10 - 1:9

Load data for 110 loads in caliber .256 Mag. Gibbs with .257 | 100gr | Sierra MatchKing bullet and 55 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".

  • No data yet

  • 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.

    .

    Loading_icon.gif

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
84%
89%
98%
Accurate 2700
85%
89%
93%
Accurate 3100
97%
76%
93%
Accurate 4350
92%
89%
97%
Alliant Reloder- TS 15.5
84%
89%
99%
Alliant Reloder-16
93%
90%
98%
Alliant Reloder-17
88%
89%
99%
Alliant Reloder-19
97%
89%
92%
Alliant Reloder-23
96%
72%
97%
Alliant Reloder-26
97%
81%
95%
Bofors RP3
84%
88%
99%
Bofors RP7
88%
90%
94%
Hodgdon H380
84%
90%
97%
Hodgdon H414
87%
89%
94%
Hodgdon H4350
93%
89%
93%
Hodgdon Hybrid 100V
95%
88%
99%
Hodgdon LVR
89%
89%
96%
Hodgdon Superperformance
90%
88%
93%
Hodgdon VARGET
84%
88%
98%
Hodgdon TrailBoss
96%
68%
100%
IMR 4064
85%
89%
98%
IMR 4166 Enduron
85%
89%
94%
IMR 4350
92%
89%
93%
IMR 4451 Enduron
86%
88%
94%
IMR 4831
97%
90%
97%
Lovex S065
89%
88%
96%
Lovex S070
91%
90%
95%
Norma 204
92%
90%
92%
Norma MRP
97%
81%
92%
Norma URP
92%
89%
97%
Ramshot Hunter
93%
89%
95%
ReloadSwiss RS 14
96%
69%
100%
ReloadSwiss RS 50
83%
89%
95%
ReloadSwiss RS 60
86%
89%
100%
ReloadSwiss RS 62
92%
88%
97%
ReloadSwiss RS 70
92%
89%
96%
Rottweil R 903
86%
89%
99%
Rottweil R 905
97%
87%
92%
Rottweil R 907
88%
90%
94%
SNPE Vectan SP 11
85%
89%
98%
SNPE Vectan Tubal 5000
84%
89%
100%
SNPE Vectan Tubal 7000
89%
89%
94%
Shooters World Long Rifle
89%
88%
96%
Somchem S355
85%
88%
99%
Somchem S365
95%
88%
100%
Somchem S385
96%
86%
93%
Vihtavuori N135
87%
89%
100%
Vihtavuori N150
91%
89%
100%
Vihtavuori N160
89%
88%
97%
Vihtavuori N550
89%
89%
97%
Vihtavuori N555
97%
79%
97%
Winchester 6.5 StaBALL
90%
88%
99%
Winchester 760
87%
89%
94%
Winchester StaBALL HD
97%
65%
95%
Winchester Supreme 780
96%
89%
92%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2208
<<locked>>
81%
39755
81%
**92
97%
[Accurate 2700]*
<<locked>>
81%
38334
78%
**94
91%
[Accurate 3100]*
<<locked>>
92%
31430
64%
**35
90%
[Accurate 4350]*
<<locked>>
81%
30139
61%
**15
92%
Alliant Reloder- TS 15.5
<<locked>>
81%
39653
80%
**25
98%
[Alliant Reloder-16]*
<<locked>>
81%
30676
62%
**31
92%
Alliant Reloder-17
<<locked>>
81%
34142
69%
**66
96%
[Alliant Reloder-19]*
<<locked>>
94%
39929
81%
**44
90%
[Alliant Reloder-23]*
<<locked>>
86%
25933
53%
**90
90%
[Alliant Reloder-26]*
<<locked>>
90%
31372
64%
**20
91%
Bofors RP3
<<locked>>
81%
39073
79%
**12
98%
[Bofors RP7]*
<<locked>>
82%
36216
73%
**84
90%
Hodgdon H380
<<locked>>
81%
39972
81%
**25
96%
[Hodgdon H414]*
<<locked>>
81%
35143
71%
**46
91%
[Hodgdon H4350]*
<<locked>>
87%
36477
74%
**13
90%
[Hodgdon Hybrid 100V]*
<<locked>>
81%
28036
57%
**30
93%
[Hodgdon LVR]*
<<locked>>
81%
33286
68%
**87
92%
[Hodgdon Superperformance]*
<<locked>>
85%
36956
75%
**92
90%
Hodgdon VARGET
<<locked>>
81%
39407
80%
**82
97%
Hodgdon TrailBoss
<<locked>>
81%
26687
54%
**36
100%
IMR 4064
<<locked>>
81%
38856
79%
**62
97%
[IMR 4166 Enduron]*
<<locked>>
81%
39015
79%
**33
92%
[IMR 4350]*
<<locked>>
85%
35955
73%
**03
90%
[IMR 4451 Enduron]*
<<locked>>
81%
37072
75%
**10
91%
[IMR 4831]*
<<locked>>
82%
27195
55%
**13
90%
[Lovex S065]*
<<locked>>
81%
34272
70%
**44
92%
[Lovex S070]*
<<locked>>
82%
33939
69%
**51
90%
[Norma 204]*
<<locked>>
90%
40785
83%
**44
90%
[Norma MRP]*
<<locked>>
94%
36970
75%
**48
90%
[Norma URP]*
<<locked>>
81%
30661
62%
**31
92%
[Ramshot Hunter]*
<<locked>>
83%
32561
66%
**74
90%
ReloadSwiss RS 14
<<locked>>
81%
27180
55%
**78
100%
[ReloadSwiss RS 50]*
<<locked>>
81%
40640
82%
**05
94%
ReloadSwiss RS 60
<<locked>>
81%
36463
74%
**48
99%
[ReloadSwiss RS 62]*
<<locked>>
81%
29878
61%
**31
91%
[ReloadSwiss RS 70]*
<<locked>>
82%
31314
63%
**61
90%
Rottweil R 903
<<locked>>
81%
36825
75%
**56
97%
[Rottweil R 905]*
<<locked>>
94%
39305
80%
**44
90%
[Rottweil R 907]*
<<locked>>
82%
36216
73%
**84
90%
SNPE Vectan SP 11
<<locked>>
81%
37913
77%
**15
97%
SNPE Vectan Tubal 5000
<<locked>>
81%
39479
80%
**13
100%
[SNPE Vectan Tubal 7000]*
<<locked>>
81%
33315
68%
**85
90%
[Shooters World Long Rifle]*
<<locked>>
81%
34272
70%
**44
92%
Somchem S355
<<locked>>
81%
37666
76%
**66
97%
[Somchem S365]*
<<locked>>
81%
27238
55%
**62
94%
[Somchem S385]*
<<locked>>
91%
36172
73%
**40
90%
Vihtavuori N135
<<locked>>
81%
36738
75%
**13
100%
Vihtavuori N150
<<locked>>
81%
32053
65%
**02
97%
[Vihtavuori N160]*
<<locked>>
81%
33243
67%
**61
93%
[Vihtavuori N550]*
<<locked>>
81%
33533
68%
**00
93%
[Vihtavuori N555]*
<<locked>>
85%
26585
54%
**39
90%
Winchester 6.5 StaBALL
<<locked>>
81%
31792
64%
**98
95%
[Winchester 760]*
<<locked>>
81%
35143
71%
**46
91%
[Winchester StaBALL HD]*
<<locked>>
91%
27108
55%
**89
91%
[Winchester Supreme 780]*
<<locked>>
94%
40190
82%
**15
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.

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

bottom of page