Load data for .256 Mag. Gibbs + .257 | 90gr | Sierra Blitzking

Recommended Powder(s): ReloadSwiss RS 52, ReloadSwiss RS 60, Somchem S365

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:	.257 \| 90gr \| Sierra Blitzking
Bullet Weight:	90gr \| 5.8g
Bullet Diameter:	0.257" \| 6.53mm
Bullet Length:	1.108" \| 28.1mm
Caliber:	.256 Mag. Gibbs load data
Case Length (l3):	2.173" \| 55.2mm
Cartridge Length (C.O.L.):	3.004" \| 76.3mm
Seated Depth:	0.277" \| 7.0mm
Shank Seated Depth:	0.137" \| 3.5mm
Case Capacity:	56.0 Grains of Water \| 3.64 cm³
Primer Size:	Large Rifle (LR)
Max. allowed Pressure:	49313 psi \| 3400 bar
LID:	LID_B5789_C231
Last updated:	2025-01-01
Recommended Twist Rate:	1:10 - 1:8

Load data for 112 loads in caliber .256 Mag. Gibbs with .257 | 90gr | Sierra Blitzking bullet and 56 powders such as ReloadSwiss RS 52, ReloadSwiss RS 60, Somchem S365. 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.

You can set your specifications in the "Personalized Load Calculator".

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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 2208	<<locked>>	87%	44222	90%	**18	97%
[Accurate 2700]*	<<locked>>	88%	44193	90%	**36	91%
Accurate 4064	<<locked>>	86%	43990	89%	**41	100%
Accurate 4350	<<locked>>	95%	44179	90%	**00	96%
Alliant Reloder- TS 15.5	<<locked>>	87%	43801	89%	**48	98%
Alliant Reloder-15	<<locked>>	85%	44295	90%	**61	97%
Alliant Reloder-16	<<locked>>	95%	44106	89%	**17	96%
Alliant Reloder-17	<<locked>>	91%	44309	90%	**53	98%
[Alliant Reloder-23]*	<<locked>>	96%	32590	66%	**25	93%
Hodgdon CFE223	<<locked>>	86%	44048	89%	**81	96%
Hodgdon H380	<<locked>>	86%	44367	90%	**41	95%
[Hodgdon H414]*	<<locked>>	90%	44164	90%	**87	93%
Hodgdon Hybrid 100V	<<locked>>	97%	42221	86%	**28	97%
Hodgdon LVR	<<locked>>	92%	43511	88%	**68	95%
Hodgdon VARGET	<<locked>>	87%	43845	89%	**12	97%
Hodgdon TrailBoss	<<locked>>	96%	33127	67%	**85	100%
IMR 3031	<<locked>>	84%	43845	89%	**58	100%
IMR 4064	<<locked>>	87%	43656	89%	**95	97%
[IMR 4166 Enduron]*	<<locked>>	88%	44208	90%	**63	93%
[IMR 4350]*	<<locked>>	94%	43859	89%	**02	92%
[IMR 4451 Enduron]*	<<locked>>	89%	43671	89%	**82	92%
IMR 4831	<<locked>>	97%	40059	81%	**92	95%
IMR 4895	<<locked>>	84%	44324	90%	**68	97%
Lovex S062	<<locked>>	85%	43656	89%	**12	98%
[Lovex S065]*	<<locked>>	91%	43540	88%	**99	94%
[Lovex S070]*	<<locked>>	93%	43845	89%	**22	93%
Norma 203B	<<locked>>	85%	43511	88%	**45	97%
Norma URP	<<locked>>	95%	44367	90%	**91	96%
Ramshot Big Game	<<locked>>	85%	44019	89%	**68	97%
[Ramshot Hunter]*	<<locked>>	96%	44280	90%	**91	94%
ReloadSwiss RS 14	<<locked>>	96%	33475	68%	**31	100%
[ReloadSwiss RS 50]*	<<locked>>	86%	43874	89%	**02	93%
ReloadSwiss RS 52 👍	<<locked>>	86%	43845	89%	**87	99%
ReloadSwiss RS 60 👍	<<locked>>	92%	43787	89%	**50	99%
ReloadSwiss RS 62	<<locked>>	95%	43787	89%	**07	96%
ReloadSwiss RS 70	<<locked>>	95%	44295	90%	**23	95%
Rottweil R 902	<<locked>>	84%	44106	89%	**05	99%
Rottweil R 903	<<locked>>	89%	44382	90%	**51	98%
[Rottweil R 907]*	<<locked>>	91%	44382	90%	**95	92%
SNPE Vectan SP 11	<<locked>>	88%	43497	88%	**71	97%
SNPE Vectan Tubal 5000	<<locked>>	87%	43990	89%	**36	100%
[SNPE Vectan Tubal 7000]*	<<locked>>	92%	43598	88%	**40	92%
[Shooters World Long Rifle]*	<<locked>>	91%	43540	88%	**99	94%
Shooters World Precision	<<locked>>	85%	43656	89%	**12	98%
Somchem S355	<<locked>>	89%	44251	90%	**45	98%
Somchem S365 👍	<<locked>>	97%	41626	84%	**91	99%
Vihtavuori N133	<<locked>>	83%	43888	89%	**33	100%
Vihtavuori N135	<<locked>>	89%	43482	88%	**92	100%
Vihtavuori N140	<<locked>>	84%	44338	90%	**99	100%
Vihtavuori N150	<<locked>>	94%	43947	89%	**09	99%
Vihtavuori N160	<<locked>>	92%	44135	90%	**45	96%
Vihtavuori N540	<<locked>>	84%	43888	89%	**12	100%
Vihtavuori N550	<<locked>>	92%	44367	90%	**97	96%
[Vihtavuori N555]*	<<locked>>	97%	34954	71%	**20	94%
Winchester 6.5 StaBALL	<<locked>>	93%	44367	90%	**28	98%
[Winchester 760]*	<<locked>>	90%	44164	90%	**87	93%

Max Load - Barrel Length: 23.60''

Powder	Charge	FR	MaxP	%	V(0)	z
[ADI AR 2208]*	<<locked>>	81%	36666	74%	**38	94%
[Accurate 2700]*	<<locked>>	85%	40698	83%	**64	90%
Accurate 4064	<<locked>>	81%	37086	75%	**81	99%
[Accurate 4350]*	<<locked>>	85%	30879	63%	**66	91%
Alliant Reloder- TS 15.5	<<locked>>	81%	36361	74%	**71	96%
Alliant Reloder-15	<<locked>>	81%	39001	79%	**36	95%
[Alliant Reloder-16]*	<<locked>>	85%	31923	65%	**76	90%
[Alliant Reloder-17]*	<<locked>>	81%	31227	63%	**89	92%
[Alliant Reloder-23]*	<<locked>>	93%	28950	59%	**00	90%
[Hodgdon CFE223]*	<<locked>>	81%	37420	76%	**20	94%
[Hodgdon H380]*	<<locked>>	81%	36666	74%	**61	93%
[Hodgdon H414]*	<<locked>>	86%	38218	78%	**40	90%
[Hodgdon Hybrid 100V]*	<<locked>>	83%	27195	55%	**05	90%
[Hodgdon LVR]*	<<locked>>	84%	33214	67%	**02	90%
[Hodgdon VARGET]*	<<locked>>	81%	36332	74%	**28	94%
Hodgdon TrailBoss	<<locked>>	81%	26382	53%	**21	100%
IMR 3031	<<locked>>	81%	39189	79%	**66	100%
[IMR 4064]*	<<locked>>	81%	36114	73%	**25	94%
[IMR 4166 Enduron]*	<<locked>>	82%	37782	77%	**18	90%
[IMR 4350]*	<<locked>>	91%	39624	80%	**13	90%
[IMR 4451 Enduron]*	<<locked>>	85%	38798	79%	**67	90%
[IMR 4831]*	<<locked>>	88%	30356	62%	**26	90%
IMR 4895	<<locked>>	81%	40016	81%	**72	96%
Lovex S062	<<locked>>	81%	38493	78%	**87	97%
[Lovex S065]*	<<locked>>	84%	34098	69%	**62	90%
[Lovex S070]*	<<locked>>	88%	37217	75%	**58	90%
Norma 203B	<<locked>>	81%	38522	78%	**27	96%
[Norma URP]*	<<locked>>	84%	31053	63%	**46	90%
Ramshot Big Game	<<locked>>	81%	38087	77%	**27	95%
[Ramshot Hunter]*	<<locked>>	90%	36260	74%	**94	90%
ReloadSwiss RS 14	<<locked>>	81%	26803	54%	**67	100%
[ReloadSwiss RS 50]*	<<locked>>	81%	37376	76%	**41	91%
ReloadSwiss RS 52	<<locked>>	81%	36956	75%	**30	97%
[ReloadSwiss RS 60]*	<<locked>>	81%	30545	62%	**66	93%
[ReloadSwiss RS 62]*	<<locked>>	86%	31952	65%	**02	90%
[ReloadSwiss RS 70]*	<<locked>>	88%	35462	72%	**87	90%
Rottweil R 902	<<locked>>	81%	40596	82%	**20	98%
Rottweil R 903	<<locked>>	81%	33649	68%	**92	95%
[Rottweil R 907]*	<<locked>>	87%	40016	81%	**94	90%
[SNPE Vectan SP 11]*	<<locked>>	81%	34737	70%	**48	94%
SNPE Vectan Tubal 5000	<<locked>>	81%	36361	74%	**76	99%
[SNPE Vectan Tubal 7000]*	<<locked>>	87%	37492	76%	**08	90%
[Shooters World Long Rifle]*	<<locked>>	84%	34098	69%	**62	90%
Shooters World Precision	<<locked>>	81%	38493	78%	**87	97%
Somchem S355	<<locked>>	81%	34389	70%	**12	95%
[Somchem S365]*	<<locked>>	81%	25309	51%	**92	90%
Vihtavuori N133	<<locked>>	81%	41104	83%	**81	100%
Vihtavuori N135	<<locked>>	81%	33402	68%	**62	99%
Vihtavuori N140	<<locked>>	81%	39914	81%	**10	100%
[Vihtavuori N150]*	<<locked>>	81%	29167	59%	**44	94%
[Vihtavuori N160]*	<<locked>>	82%	31038	63%	**17	90%
Vihtavuori N540	<<locked>>	81%	39711	81%	**27	99%
[Vihtavuori N550]*	<<locked>>	81%	31140	63%	**59	90%
[Vihtavuori N555]*	<<locked>>	91%	29428	60%	**46	90%
[Winchester 6.5 StaBALL]*	<<locked>>	81%	29399	60%	**35	92%
[Winchester 760]*	<<locked>>	86%	38218	78%	**40	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