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Load data for .256 Win. Mag. + .257 | 120gr | Speer Boat-Tail

Recommended Powder(s):

.256 Win. Mag. + .257 | 120gr | Speer Boat-Tail

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.257 | 120gr | Speer Boat-Tail
Manufacturer SKU:
1410
Bullet Weight:
120gr | 7.8g
Bullet Diameter:
0.257" | 6.53mm
Bullet Length:
1.140" | 29.0mm
Caliber:
.256 Win. Mag. load data
Case Length (l3):
1.281" | 32.5mm
Cartridge Length (C.O.L.):
<<locked>>
Seated Depth:
<<locked>>
Shank Seated Depth:
<<locked>>
Case Capacity:
22.0 Grains of Water | 1.43 cm³
Primer Size:
Large Rifle (LR)
Max. allowed Pressure:
50763 psi | 3500 bar
LID:
LID_B6092_C233
Last updated:
2026-03-23
Recommended Twist Rate:
1:10 - 1:8

Load data for 34 loads in caliber .256 Win. Mag. with .257 | 120gr | Speer Boat-Tail bullet and 17 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 2205
92%
87%
100%
ADI AR 2207
97%
57%
95%
Accurate 5744
90%
87%
96%
Accurate No. 11 FS
91%
87%
99%
Alliant Reloder-7
97%
60%
91%
Hodgdon LilGun
87%
87%
100%
IMR 4227
96%
75%
96%
Lovex D060
92%
87%
96%
Lovex D063
90%
88%
96%
Lovex S040
85%
87%
100%
Lovex S053
96%
71%
99%
ReloadSwiss RS 36
96%
71%
96%
SNPE Vectan BA6 1/2
96%
66%
100%
Shooters World Blackout
90%
88%
96%
Shooters World Buffalo Rifle
92%
87%
96%
Vihtavuori N110
96%
85%
100%
Vihtavuori N120
96%
53%
95%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2205
<<locked>>
81%
31633
62%
***
98%
[ADI AR 2207]*
<<locked>>
89%
23279
46%
***
92%
[Accurate 5744]*
<<locked>>
81%
33547
66%
***
93%
Accurate No. 11 FS
<<locked>>
81%
31807
63%
***
96%
[Alliant Reloder-7]*
<<locked>>
94%
28021
55%
***
90%
Hodgdon LilGun
<<locked>>
82%
36390
72%
***
100%
[IMR 4227]*
<<locked>>
84%
27543
54%
***
92%
[Lovex D060]*
<<locked>>
81%
32010
63%
***
92%
[Lovex D063]*
<<locked>>
81%
33997
67%
***
93%
Lovex S040
<<locked>>
82%
39885
79%
***
100%
Lovex S053
<<locked>>
85%
25788
51%
***
96%
[ReloadSwiss RS 36]*
<<locked>>
84%
25411
50%
***
91%
SNPE Vectan BA6 1/2
<<locked>>
91%
29211
58%
***
100%
[Shooters World Blackout]*
<<locked>>
81%
33997
67%
***
93%
[Shooters World Buffalo Rifle]*
<<locked>>
81%
32010
63%
***
92%
Vihtavuori N110
<<locked>>
81%
27572
54%
***
100%
[Vihtavuori N120]*
<<locked>>
93%
24671
49%
***
94%

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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