.505 Magnum Gibbs

Technical Specifications

 

Country of Origin United States
Diameter – Bore .494” (12,55mm)
Diameter – Groove .504” (12,80mm)
Introduced 1911
Pressure – Max Average 39,160 psi (270 MPa)
Regulators CIP
Groove Details 5 x .210” (5,33mm)
Shellholder – RCBS 47
Twist – Proof Barrel 1:15.98” (402mm)
* Read all about this cartridge in the book African Dangerous Game Cartridges by Pierre van der Walt
Cartridge Essentials

 

Action Size Recommended Miniature length & .223 bolt face
Barrel Life 8,000 – 9,000 rounds
Case – Body Taper 1.0°
Case – Neck Length .652” (16,56mm) =
Case – Trim Length 3.142” (79,81mm)
Parent Case Original
Relative Capacity 181.0 gr water (11,752mm)
Shoulder Angle 37°34’55”
Typical Factory Load Guidelines for Africa – Solids
Brand Name Bullet Weight Bullet Description Velocity Fps Energy Ft/Lb Trauma Potential 100% Expansion
Norma 600-gr PH Solid 2,100 fps 5,877 ft/lb 91.6
Norma 540-gr Norma Mono Solid 2,300 fps 6,345 ft/lb 98.9
Kynoch 525-gr Woodleigh Solid 2,300 fps 6,168 fp/lb 96.2
Nosler 525-gr Safari Solid 2,200 fps 5,644 ft/lb 88.0
Typical Factory Load Guidelines for Africa – Expanders
Brand Name Bullet Weight Bullet Description Velocity Fps Energy Ft/Lb Trauma Potential 100% Expansion
Norma 600-gr African PH Solid 2,100 fps 5,877 ft/lb 45.8
Kynoch 525-gr Woodleigh RN-SP 2,300 fps 6,168 fp/lb 48.1
Optimum Game Bullet Optimum Application Bands (525-gr averaged)
Band Velocity Parameters Start End
Green-Band ( ≤ 2,600 fps – ≥ 2,200 fps) ± 0 yds ± 50 yds
Amber-Band ( ≤ 2,200 fps – ≥ 2,000 fps) ± 50 yds ± 150 yds
* Read all about this cartridge in the book African Dangerous Game Cartridges by Pierre van der Walt
Bullet Recommendations for Africa
All species Solids. On pachyderms use flat nose monometal solids
African Game Weight Recommendation
≤ 13,000 lb ( ≤ 6000 kg)
Most Suitable African Species (assuming legality)
Pachederms Buffalo, elephant, (body shots),
* Read all about these animals in the book Game Animals of the World by Chris & Tilde Stuart
Optics Guidelines
Eye Relief Critical ≥ 4.0”
Exit Pupil ≤ 5mm
Magnification: Amber-Band ≥ 1x
Objective Lens ≥ 20mm – ≤ 24mm
Parallax Adjustability No
Bold posts. German #1, #2, #4, #9, #56
Consider illuminated dots
Consider reflex sights
Handloading Guidelines
Load Development 1.0 grain increments
Primer Federal 215 Large Rifle Magnum
Propellant Range Slow-to Ultra-slow rifle: ≥ Hodgdon H-4831 – ≤ Hodgdon H-1000
Tips Use Lee factory crimp to crimp bullets with no shoulder damage
Use foam filler to improve combustion consistency
Full length resize hunting loads
Check feeding before hunt
* Read all about this cartridge in the book African Dangerous Game Cartridges by Pierre van der Walt