Load data for .256 Mag. Gibbs + .257 | 70gr | Sierra Blitzking

Recommended Powder(s): Accurate 4064, IMR 3031

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:	.257 \| 70gr \| Sierra Blitzking
Manufacturer SKU:	1605
Bullet Weight:	70gr \| 4.5g
Bullet Diameter:	0.257" \| 6.53mm
Bullet Length:	0.874" \| 22.2mm
Caliber:	.256 Mag. Gibbs load data
Case Length (l3):	2.173" \| 55.2mm
Cartridge Length (C.O.L.):	2.925" \| 74.3mm
Seated Depth:	0.122" \| 3.1mm
Shank Seated Depth:	0.122" \| 3.1mm
Case Capacity:	56.0 Grains of Water \| 3.64 cm³
Primer Size:	Large Rifle (LR)
Max. allowed Pressure:	49313 psi \| 3400 bar
LID:	LID_B5786_C231
Last updated:	2025-01-01

Load data for 106 loads in caliber .256 Mag. Gibbs with .257 | 70gr | Sierra Blitzking bullet and 53 powders such as Accurate 4064, IMR 3031. 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".
A load must fulfill certain criteria to be listed in the default view below - see "powder criteria to fulfill to be listed".

Our load data might deviate from other sources - see the "most common reasons for deviations".

All loads are based on the bullet and case dimensions shown under "Load Specifications" - see "reloading suggestions" if you deviate.

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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.
Case Length (Inch)
Case Length (mm)
CaseCapacity (GoW)
Min z (%)
Min FR (%)
Max FR*
Barrel Length (Inch)
Barrel Length (cm)
Safety Buffer (%)
.

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 2206H	<<locked>>	86%	43627	88%	**53	95%
[ADI AR 2208]*	<<locked>>	91%	44048	89%	**33	94%
[Accurate 2200]*	<<locked>>	84%	43584	88%	**87	92%
Accurate 2495	<<locked>>	86%	44121	89%	**83	100%
Accurate 2520	<<locked>>	85%	44092	89%	**66	98%
Accurate 4064 👍	<<locked>>	92%	44324	90%	**86	99%
Alliant AR-Comp	<<locked>>	86%	44193	90%	**99	100%
Alliant Reloder- TS 15.5	<<locked>>	92%	44353	90%	**89	96%
[Alliant Reloder-15]*	<<locked>>	90%	43845	89%	**76	94%
Alliant Reloder-17	<<locked>>	96%	43772	89%	**35	95%
[Baschieri & Pellagri 107]*	<<locked>>	87%	44295	90%	**56	93%
Hodgdon BL-C2	<<locked>>	85%	43569	88%	**76	96%
[Hodgdon CFE223]*	<<locked>>	90%	43874	89%	**86	93%
[Hodgdon H380]*	<<locked>>	91%	44367	90%	**53	92%
[Hodgdon VARGET]*	<<locked>>	92%	44367	90%	**37	94%
Hodgdon TrailBoss	<<locked>>	96%	32140	65%	**31	100%
IMR 3031 👍	<<locked>>	90%	43569	88%	**15	100%
[IMR 4064]*	<<locked>>	92%	43903	89%	**27	94%
IMR 4895	<<locked>>	89%	44063	89%	**96	95%
IMR 8208 XBR	<<locked>>	85%	44309	90%	**43	96%
Lovex D073.6	<<locked>>	87%	43511	88%	**56	98%
Lovex S060	<<locked>>	85%	43758	89%	**71	95%
Lovex S062	<<locked>>	90%	44353	90%	**53	96%
Norma 201	<<locked>>	87%	43888	89%	**30	96%
Norma 202	<<locked>>	87%	43845	89%	**53	98%
Norma 203B	<<locked>>	90%	44237	90%	**86	95%
[Ramshot Big Game]*	<<locked>>	90%	44135	90%	**89	94%
[Ramshot Wild Boar]*	<<locked>>	85%	43990	89%	**50	94%
ReloadSwiss RS 14	<<locked>>	97%	32764	66%	**90	100%
ReloadSwiss RS 52	<<locked>>	91%	44295	90%	**32	97%
ReloadSwiss RS 60	<<locked>>	96%	43627	88%	**32	96%
Rottweil R 901	<<locked>>	84%	44295	90%	**30	98%
Rottweil R 902	<<locked>>	89%	44295	90%	**23	96%
Rottweil R 903	<<locked>>	94%	43526	88%	**66	95%
[SNPE Vectan SP 11]*	<<locked>>	93%	44005	89%	**89	94%
[SNPE Vectan SP 7]*	<<locked>>	85%	43772	89%	**04	92%
SNPE Vectan SP 9	<<locked>>	87%	43990	89%	**50	95%
SNPE Vectan Tubal 3000	<<locked>>	86%	44164	90%	**71	98%
SNPE Vectan Tubal 5000	<<locked>>	91%	43743	89%	**68	99%
Shooters World Match Rifle	<<locked>>	87%	43511	88%	**56	98%
Shooters World Precision	<<locked>>	90%	44353	90%	**53	96%
Somchem S335	<<locked>>	86%	43656	89%	**68	99%
Somchem S341	<<locked>>	86%	44251	90%	**27	95%
Somchem S355	<<locked>>	94%	44295	90%	**56	95%
[Somchem S365]*	<<locked>>	97%	34737	70%	**79	93%
Vihtavuori N133	<<locked>>	88%	44034	89%	**84	100%
Vihtavuori N135	<<locked>>	95%	44251	90%	**50	100%
Vihtavuori N140	<<locked>>	89%	44222	90%	**30	99%
Vihtavuori N150	<<locked>>	97%	40901	83%	**61	96%
[Vihtavuori N160]*	<<locked>>	97%	43656	89%	**43	92%
Vihtavuori N540	<<locked>>	89%	43903	89%	**37	98%
[Vihtavuori N550]*	<<locked>>	97%	43642	89%	**89	92%
Winchester 6.5 StaBALL	<<locked>>	97%	43381	88%	**87	95%

Max Load - Barrel Length: 23.60''

Powder	Charge	FR	MaxP	%	V(0)	z
[ADI AR 2206H]*	<<locked>>	81%	37173	75%	**82	92%
[ADI AR 2208]*	<<locked>>	85%	35998	73%	**10	90%
[Accurate 2200]*	<<locked>>	81%	39523	80%	**92	91%
Accurate 2495	<<locked>>	81%	36825	75%	**15	99%
Accurate 2520	<<locked>>	81%	37913	77%	**28	96%
Accurate 4064	<<locked>>	81%	30937	63%	**22	95%
Alliant AR-Comp	<<locked>>	81%	37782	77%	**61	100%
[Alliant Reloder- TS 15.5]*	<<locked>>	82%	31096	63%	**22	90%
[Alliant Reloder-15]*	<<locked>>	83%	35070	71%	**30	90%
[Alliant Reloder-17]*	<<locked>>	89%	34519	70%	**66	90%
[Baschieri & Pellagri 107]*	<<locked>>	81%	36970	75%	**69	90%
[Hodgdon BL-C2]*	<<locked>>	81%	37811	77%	**28	94%
[Hodgdon CFE223]*	<<locked>>	86%	38174	77%	**28	90%
[Hodgdon H380]*	<<locked>>	88%	39059	79%	**22	90%
[Hodgdon VARGET]*	<<locked>>	85%	35578	72%	**00	90%
Hodgdon TrailBoss	<<locked>>	81%	25744	52%	**57	100%
IMR 3031	<<locked>>	81%	32735	66%	**23	97%
[IMR 4064]*	<<locked>>	85%	35099	71%	**91	90%
[IMR 4895]*	<<locked>>	81%	33779	68%	**07	90%
IMR 8208 XBR	<<locked>>	81%	39189	79%	**15	95%
Lovex D073.6	<<locked>>	81%	35157	71%	**53	95%
[Lovex S060]*	<<locked>>	81%	38058	77%	**30	92%
[Lovex S062]*	<<locked>>	81%	32634	66%	**35	92%
[Norma 201]*	<<locked>>	81%	36709	74%	**40	94%
Norma 202	<<locked>>	81%	36318	74%	**59	96%
[Norma 203B]*	<<locked>>	82%	33866	69%	**00	90%
[Ramshot Big Game]*	<<locked>>	83%	34838	71%	**33	90%
[Ramshot Wild Boar]*	<<locked>>	81%	38232	78%	**09	92%
ReloadSwiss RS 14	<<locked>>	81%	25556	52%	**96	100%
[ReloadSwiss RS 52]*	<<locked>>	81%	31053	63%	**58	91%
[ReloadSwiss RS 60]*	<<locked>>	89%	33692	68%	**33	90%
Rottweil R 901	<<locked>>	81%	39958	81%	**32	97%
[Rottweil R 902]*	<<locked>>	81%	34737	70%	**81	93%
[Rottweil R 903]*	<<locked>>	85%	31560	64%	**28	90%
[SNPE Vectan SP 11]*	<<locked>>	86%	34708	70%	**30	90%
[SNPE Vectan SP 7]*	<<locked>>	83%	39523	80%	**99	90%
[SNPE Vectan SP 9]*	<<locked>>	81%	35926	73%	**40	91%
SNPE Vectan Tubal 3000	<<locked>>	81%	38377	78%	**33	97%
SNPE Vectan Tubal 5000	<<locked>>	81%	31198	63%	**43	96%
Shooters World Match Rifle	<<locked>>	81%	35157	71%	**53	95%
[Shooters World Precision]*	<<locked>>	81%	32634	66%	**35	92%
Somchem S335	<<locked>>	81%	37826	77%	**33	98%
[Somchem S341]*	<<locked>>	81%	36796	75%	**40	92%
[Somchem S355]*	<<locked>>	84%	31807	64%	**28	90%
[Somchem S365]*	<<locked>>	93%	30806	62%	**48	90%
Vihtavuori N133	<<locked>>	81%	35578	72%	**84	99%
Vihtavuori N135	<<locked>>	81%	28021	57%	**13	96%
Vihtavuori N140	<<locked>>	81%	33823	69%	**64	96%
[Vihtavuori N150]*	<<locked>>	85%	28485	58%	**00	90%
[Vihtavuori N160]*	<<locked>>	93%	38595	78%	**12	90%
Vihtavuori N540	<<locked>>	81%	33721	68%	**84	95%
[Vihtavuori N550]*	<<locked>>	93%	38522	78%	**51	90%
[Winchester 6.5 StaBALL]*	<<locked>>	90%	33692	68%	**25	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.

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