.505 Gibbs

I'm not sure that we're disagreeing, though I can see how my post may have miscommunicated. I, too, would advocate most anything 50 cal over the 416 Rigby for buffalo. My point, was that the 505 Gibbs has a monster powder volume. It longs for a shoving flat ballistic. If such volume is not used then a smaller volume 50 calibre is in order, of which there are several.

By way of analogy, I say the same at the 416 level. The reason for the Rigby is to use the massive powder volume. with comfortable 6000 ftlb loads. Otherwise a person should opt for cartridges with a lesser volume like the 416 Rem/Ruger.
 
416Tarzan,

This may get me in trouble with someone we both know but I am thinking about building a 505 Gibbs on a GMA action and shooting loads similar to the original. I know the 500AR and Michael's 500MDM will work fine and can be built in a lighter, more handy package. However some of hunting in Africa is nostalgia. Nothing like a fine 505 Gibbs. My WILL feed Flatnose Solids. Just please do not tell Michael M about the Gibbs.

This Barrie Duckworth's 505 Gibbs in a 1930's vintage George Gibbs rifle.

505GibbsI.jpg
 
416,

I'm sorry, I read in to that you thought that the 416 preformed like the 50 cals. I see you were just talking about efficiency. Point taken.

Ed
 
Today I was in Church My church - the CZ Shop in Prague and what did they have on the shelf a 505 gibbs !!!!!!

Man this might end up an expensive trip !!!!!!
 
Since the discussion above a few years ago I have built a 500 **NOT**PERMITTED** Nyati.
It is .510", using a Rigby-size case, but limited to 2.65" in order to fit a Ruger Hawkeye action.
(Nyati refers to the throat configuration of a 0.255" freebore.)
More importantly, this handles up to 7000 foot-pound muzzle energies, accurately. That is more than enough for my needs.

Here is a recent load, 3-shot 100 yard, pupil of buffalo:
bGQESx3.jpg



In order to shoot flat-nose solids I have modified the feed-ramp with a Dremel rotary tool. The bright light on the right is a flashlight and the modifications show up at the bottom of the ramp on the left. Both the bottom of the ramp and well as the sides of the ramp were smoothed-out and opened-up:
Jpw9m74.jpg

Such modifications can be recommended for any 500 rifle that cannot feed a flat-nose solid smoothly.


Finally, the recoil is substantial but manageable:
dzci9N8.jpg



I have only admiration for the 505 Gibbs. It has a capacity for loads that exceed 8,000 foot-pounds.
The 500AccRelNyati is for hunting loads in an inexpensive, lighter rifle, yet at the energy levels of factory 505Gibbs and 500Jeffery.
 

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.505 Gibbs

The .505 Gibbs has a case capacity of 178 grains (11.5 g). This cartridge was originally loaded with 90-grain (5.8 g) of cordite and 525-grain (34.0 g) bullet at 2,300 ft/s (700 m/s) for 6,166 ft•lbf (8,360 J) of kinetic energy. While the .505 Gibbs has a greater case capacity than most modern cartridges, it is loaded to lower pressures. The C.I.P. recommends a pressure standard of 2,700 bars (39,160 p.s.i.) for the cartridgeAs .505 Gibbs was intended for hunting dangerous game in a tropical environment and due to the temperature sensitivity of cordite the lower pressures provided a greater safety and reliability margin.

The .505 Gibbs has a unique bullet diameter of .505 inches (12.80 mm) while most other .50 caliber bullets have diameters of .510 inches (12.95 mm). Barnes Bullets and Woodleigh Bullets are a few of bullet manufacturers who produce component bullets for reloading in this caliber. Woodleigh Bullets does not recommend impact velocities of over 2,250 ft/s (690 m/s) for their .505 caliber 525 gr. Weldcore bullets.

Ceska Zbrojovka (CZ) currently manufactures the Safari Classics rifle for this cartridge. Modern semi-automatic rifles are also available in this cartridge from Vigilance Rifles.A-Square, Norma and Kynoch are offering loaded ammunition in 505 Gibbs.

Type rifle
• Place of origin: England
• Production history: Designer George Gibbs
• Designed: 1911

Specifications
• Parent case: none
• Case type: Rimless, Bottleneck
• Bullet diameter: .505 in (12.8 mm)
• Neck diameter: .538 in (13.7 mm)
• Shoulder diameter: .640 in (16.3 mm)
• Base diameter: .640 in (16.3 mm)
• Rim thickness: unknown
• Case length: 3.150 in (80.0 mm)
• Overall length: 3.850 in (97.8 mm)
• Primer type

Ballistic performance
Test barrel length: 24"
Bullet weight/type - Velocity - Energy
• 600 gr (39 g) Protected Point - 2,100 ft/s (640 m/s) - 5,877 ft•lbf (7,968 J)
• 600 gr (39 g) FMJ - 2,100 ft/s (640 m/s) - 5,877 ft•lbf (7,968 J)
• 525 gr (34.0 g) Welded Core SP - 2,300 ft/s (700 m/s) - 6,180 ft•lbf (8,380 J)


Monish
My new MRC 505 Gibbs. Everything is Yuuuge on this including a .800 bolt diameter!!

6747A934-2283-48BF-8E32-41C629F9367E.jpeg
 
Last edited by a moderator:
Very nice picture of a great gun.

My son and I have talked of a 505 Gibbs.
But price does weigh in. After the relatively expensive CZ factory price 250 percent over the their 416 Rigby field model, one must add special reloading tools for the large 505 cases. I figure the whole rifle would end up about $5500, tested, scoped, and handloaded with 100 rounds. (The new and ugly Bushnell 1.25-8 has 6"-5" eye relief.)

ON the earlier question of loading and comparisons with the Jeffrey, the only reason that I can see for getting a 505 Gibbs, or a 450 or 416 Rigby for that matter, is to load them up to their true bolt-action potential. Otherwise, those 'new' little 416 Rugers would be wonderfully cost efficient. 'Fully loaded' means in the 8000 ft lb range for the 505. With handloading, the 505 should have about 50-100 fps advantage over the 500 Jeffrey because of larger powder capacity. But that advantage only applies to optimum handloads and would produce over 8000 ftlbs. I would aim at 2650 fps with the 525 grain bullets (8185 ftlb), and 2500 with the 600 grainers (8325ftlbs).
That should get a buffalo's attention. I haven't fired such loads, and I imagine that they would get the shooter's attention, too. If one wanted lesser ftlbs, then a lesser calibre would be more efficient. The 416 is a delightful 'light' rifle, where one can load 350 grains to 2800 fps comfortably, with a more pleasant 6091 ft lbs.
Actually, you don’t even need that kind of power. Gibbs are best in that 2250-2400 range depending on the slug.... Just IMHO.... and from what I’ve read (I have a 505 but have NO field African experience). I loove mine it is a tank
 
I see what you say-- the Gibbs can be found for around 2500 to 2600 and that is a good deal. My CZ feeds and acts like it should. There is alot of feeding work and action work that go into that 250% cost. The Gibbs and the 500 jeffery are expensive to feed and take care of too, but...

I have do disagree with you on the rest of your post. NO 416 hits like a 50 cal/ no way no how--not even close!!! I have a 416 Rigby, 458 winchester, 450/400 double, 9.3x62,375 wby, 375 H&H..... and none of them hit like the 505, 500 jeffery, or my 500 double. I repete not even close!!!

I can see by your other statements that you have not shot alot of 50's and over by your reloading data. My gibbs tips the scales at right at 10lbs with 3 rounds in her. 600 grain bullet at 2500 fps would knock the holy hell out of you, and in my gun be almost uncontrollable. The 600 at 2250 is about at my limit in my gun, and will bowl over anything that needs its ass kicked. No use hotrodding the gibbs. It was meant to be a low pressure (for tropical conditions) ass kicker and it does it great at 525 at 2300 to 2350 or a 600 grain pill at 2150-2250.
I couldn’t agree more
 
416Tarzan,

This may get me in trouble with someone we both know but I am thinking about building a 505 Gibbs on a GMA action and shooting loads similar to the original. I know the 500AR and Michael's 500MDM will work fine and can be built in a lighter, more handy package. However some of hunting in Africa is nostalgia. Nothing like a fine 505 Gibbs. My WILL feed Flatnose Solids. Just please do not tell Michael M about the Gibbs.

This Barrie Duckworth's 505 Gibbs in a 1930's vintage George Gibbs rifle.

505GibbsI.jpg
And that GMA action is Sweeeeeeeeet!
 
I have hunted Australian water buffalo with a .505 Gibbs ( which was custom built on a pattern 14 Enfield action ) and 600 grain Woodleigh round nosed steel jacketed solids ( Norma factory loads ) . It is an excellent calibre , clearly outmatching anything in the .450 class in terms of stopping power and delivering shock to the central nervous system of dangerous game .
 
I have hunted Australian water buffalo with a .505 Gibbs ( which was custom built on a pattern 14 Enfield action ) and 600 grain Woodleigh round nosed steel jacketed solids ( Norma factory loads ) . It is an excellent calibre , clearly outmatching anything in the .450 class in terms of stopping power and delivering shock to the central nervous system of dangerous game .
Awesome post
 
All the times I searched Gunbroker for a 500 Jeff, the 505 never occurred to me. Lesson learned.
 
I have hunted Australian water buffalo with a .505 Gibbs ( which was custom built on a pattern 14 Enfield action ) and 600 grain Woodleigh round nosed steel jacketed solids ( Norma factory loads ) . It is an excellent calibre , clearly outmatching anything in the .450 class in terms of stopping power and delivering shock to the central nervous system of dangerous game .

I have to concurr...I shot a CZ550 in .505 Gibbs at Norma´s own shooting range with the same ammo...recoil was substantial but very managable... My thought was that I could easily have taken that rifle out in dense bush and hunted elephant..
 
Pat Bromfield circa 1964 about to engage an angry Herd in Chobe original 505 at the ready!

Great photo! As someone who has hunted with his own 505 I can say while the recoil is substantial it’s definitely doable. You will have to see the impact to believe the sheer force of this caliber.
On my last Cape buffalo safari in Zambia I had a chance to harvest 2 bulls with one shot kills on each. The last one did a back flip after he was shot through the shoulders.
 
416Tarzan,

This Barrie Duckworth's 505 Gibbs in a 1930's vintage George Gibbs rifle.

505GibbsI.jpg
Barries rifle is serial #2, the location of serial#1 is known (also a 505). Looks like your up at the old coppermine in the SVC.
 
Barries rifle is serial #2, the location of serial#1 is known (also a 505). Looks like your up at the old coppermine in the SVC.
#2? Please elaborate on this. I know Richard Harland’s ,Barrie Duckworth and Pat Bromfield’s -aka the Lone Ranger- 505 Gibbs rifles are all consecutively numbered from Gibbs.
If you are referring to the last number of the serial then #2 is correct. In which case the Lone Ranger would be #3.
 

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