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

Recommended Powder(s): Accurate No. 11 FS, Vihtavuori N110

.256 Win. Mag. + .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 Win. Mag. load data
Case Length (l3):
1.281" | 32.5mm
Cartridge Length (C.O.L.):
1.566" | 39.8mm
Seated Depth:
0.676" | 17.2mm
Shank Seated Depth:
0.676" | 17.2mm
Case Capacity:
22.0 Grains of Water | 1.43 cm³
Primer Size:
Large Rifle (LR)
Max. allowed Pressure:
50763 psi | 3500 bar
LID:
LID_B5794_C233
Last updated:
2025-01-01

Load data for 32 loads in caliber .256 Win. Mag. with .257 | 100gr | Sierra SPT Pro-Hunter bullet and 16 powders such as Accurate No. 11 FS, Vihtavuori N110. 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. 13.5 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 2205
<<locked>>
92%
43685
86%
**06
99%
[ADI AR 2207]*
<<locked>>
97%
28529
56%
**21
94%
Accurate 5744
<<locked>>
89%
42424
84%
**55
95%
Accurate No. 11 FS 👍
<<locked>>
91%
44686
88%
**85
98%
Hodgdon LilGun
<<locked>>
88%
45063
89%
**51
100%
IMR 4227
<<locked>>
95%
36419
72%
**67
95%
Lovex D060
<<locked>>
91%
42424
84%
**55
95%
Lovex D063
<<locked>>
90%
45498
90%
**88
95%
Lovex S040
<<locked>>
84%
42612
84%
**96
100%
Lovex S053
<<locked>>
95%
34389
68%
**64
98%
ReloadSwiss RS 36
<<locked>>
97%
36680
72%
**16
95%
SNPE Vectan BA6 1/2
<<locked>>
96%
33460
66%
**75
100%
Shooters World Blackout
<<locked>>
90%
45498
90%
**88
95%
Shooters World Buffalo Rifle
<<locked>>
91%
42424
84%
**55
95%
Vihtavuori N110 👍
<<locked>>
96%
42598
84%
**46
100%
[Vihtavuori N120]*
<<locked>>
95%
25846
51%
**32
94%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2205
<<locked>>
82%
31778
63%
**36
97%
[ADI AR 2207]*
<<locked>>
89%
22785
45%
**83
90%
[Accurate 5744]*
<<locked>>
81%
33417
66%
**14
92%
Accurate No. 11 FS
<<locked>>
81%
32634
64%
**11
96%
Hodgdon LilGun
<<locked>>
81%
34824
69%
**26
100%
[IMR 4227]*
<<locked>>
83%
26556
52%
**83
91%
[Lovex D060]*
<<locked>>
80%
31082
61%
**65
90%
[Lovex D063]*
<<locked>>
81%
33054
65%
**04
91%
Lovex S040
<<locked>>
81%
39233
77%
**50
100%
Lovex S053
<<locked>>
84%
25048
49%
**86
95%
[ReloadSwiss RS 36]*
<<locked>>
86%
26832
53%
**32
91%
SNPE Vectan BA6 1/2
<<locked>>
87%
26194
52%
**57
100%
[Shooters World Blackout]*
<<locked>>
81%
33054
65%
**04
91%
[Shooters World Buffalo Rifle]*
<<locked>>
80%
31082
61%
**65
90%
Vihtavuori N110
<<locked>>
81%
27485
54%
**29
100%
[Vihtavuori N120]*
<<locked>>
89%
22191
44%
**44
91%

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.

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