.270 Winchester

Technical Specifications

Country of Origin United States
Diameter – Bore .270” (6,86mm)
Diameter – Groove .277” (7,04mm)
Introduced 1925
Pressure – Max Average 65,000 psi (448 MPa)
Regulators SAAMI & CIP
Groove Details 4 x 0.160” (4,06 mm)
Shellholder – RCBS 3
Twist – Proof Barrel 1:10” (254mm)
* Read all about this cartridge in the book African Medium Bore Cartridges by Pierre van der Walt
Cartridge Essentials

 

Action Size Recommended Miniature length .223 bolt face
Barrel Life 2,200 – 2,900 rounds
Case – Body Taper .98°
Case – Neck Length .3843” (9,76mm) = 117.8%
Case – Trim Length 2.532” (64,31 mm)
Parent Case .30-06 Springfield
Relative Capacity 67.0 gr water (4,350cc)
Shoulder Angle 17°30’
Typical Factory Load Guidelines for Africa
Brand Name Bullet Weight Bullet Description Velocity Fps Energy Ft/Lb Trauma Potential 100% Expansion
Federal 150-gr Vital Shok 2,830 fps 2,668 ft/lb 37.9
Hornady 150-gr Interlock 2,840 fps 2,687 ft/lb 38.2
Norma 150-gr Oryx 2,854 fps 2,714 ft/lb 38.6
PMP 150-gr ProAm 2,756 fps 2,530 ft/lb 36.0
Remington 150-gr Core-Lokt 2,850 fps 2,706 ft/lb 38.5
Barnes 130-gr Vort-tx 3,060 fps 2,704 ft/lb 38.4
Federal 130-gr Vital Shok 3,060 fps 2,704 ft/lb 38.4
Hornady 130-gr SST 3,060 fps 2,704 ft/lb 38.4
PMP 130-gr ProAm 2,953 fps 2,518 ft/lb 35.8
Norma 130-gr Soft Point 3,140 fps 2,847 ft/lb 40.5
Remington 130-gr Swift Scirocco 3,060 fps 2,704 ft/lb 38.4
Winchester 130-gr Power Point 3,060 fps 2,704 ft/lb 38.4
Optimum Game Bullet Application Bands (averaged)
Band Velocity Parameters Start End
Red-Band ( > 2,600 fps) 0 yds ± 125 yds
Green-Band ( ≤ 2,600 fps – ≥ 2,200 fps) ± 125 yds ± 350 yds
Amber-Band ( ≤ 2,200 fps – ≥ 2,000 fps ± 350 yds ± 465 yds
Bullet Recommendations for Africa
Red-Band Fifth generation bonded core or seventh generation monometal
Green-Band High BC boattail fourth generation or fifth generation jacketed bullets
High BC six generation or seventh generation monometal bullets
Amber-Band High BC fourth generation bullets
* Read all about this cartridge in the book African Medium Bore Cartridges by Pierre van der Walt
African Game Weight Recommendation
≤ 450-lb ( ≤ 200-kg)
Most Suitable African Species (assuming legality)
Plains Game Addax, black wildebeest, bushpig, hartebeest, lechwe, leopard, nyala, scimitar-horned oryx, puku, sitatunga, tsessebe and warthog
* Read all about these animals in the book Game Animals of the World by Chris & Tilde Stuart
Optics Guidelines
Eye Relief Non critical
Exit Pupil ≤ 3mm
Magnification: Red-Band ≥ 3x
Magnification: Green-Band ≥ 10 – ≤ 14x
Magnification: Amber-Band ≥ 18x – ≤ 20x
Objective Lens ≥ 50mm – ≤ 56mm
Parallax Adjustability Yes
Reticules Fine duplex
Handloading Guidelines
Load Development 0.5 grain increments
Primer Standard Large Rifle
Propellant Range 150-gr: Ultra-slow rifle: ≥ H-4350 to ≤ Hodgdon H-1000
130-gr: Slow-burning rifle: ≥ Hodgdon H-4350 to ≤ Hodgdon H-4831
Tips Nothing specific
* Read all about this cartridge in the book African Medium Bore Cartridges by Pierre van der Walt