I just relieved Rich of his CZ 550 in 505 Gibbs. Very excited to start loading for it! (Thanks Rich!)

Question though, I have been shooting a 450 Dakota for a while now, and I have been shooting 500 grain bullets at around 2400 FPS. From what I am reading, the Gibbs is typically loaded with 525 grain bullets at around 2100 FPS. (maybe I am wrong on this, but it is what I am seeing).

Why are these not more commonly loaded to shoot a larger bullet, like 600 or 650? Seems puzzling to me to make such a large step up in caliber and only shoot a bullet that is 25 grains heavier.

I think the orginal load was 525/2300fps.

Why 525? Why not! I'm sure it sounded good at the time.

Check out woodleigh the make a nice 600 grain PP bullet!

Cheers,

Ed

Congratulations Rob, great calibre, moderate recoil, lots of history!

Do you have any reloading recipes? I aim to reload soon, and am looking for down-loaded recipes for the 505.

Good question.

I think the origial load was faster than 2100 fps.

I was told a few years ago that Gibbs made a bit of a mistake in loading the 525gn bullet and the calibre was always haging out for a heavier one.

Same as the 500 Jeffrey which suffered from the 535gn projjie but other options in .510 bullets were available (570gn 500 Nitro for a start).

The 600gn PP from Woodleigh worked well on the Water Buffalo I shot quite a few of them). They don't open up quite as fast as the RN.

Enjoy the 505, it's a great calibre.

.

The original load for the .505 was actually a 600-grain bullet at an alleged 2 150 fps. A friend of mine has an original Gibbs rifle with proof marks for the 600-grain bullet. I've actually fired it once or twice with 525-grain handloads.

Why was it changed to 525? Well, another friend who knows more than I do about old English rifles reckons recoil with 600-grain bullets was a bit too much of a good thing, and I'm inclined to believe him! It still hits with quite a punch, even with 525's at 2 200 or so, which was what two original loads did when we chronographed them.

The .505 cartridge has a helluva reputation but I'm not enamoured with the original rifles at all. They feel too much like hand cannons to me and an original pre-1939 .416 Rigby is more my idea of what a big-bore magazine rifle should look and handle like.

525 grains in .505 caliber is a less than optimal bullet weight.

A heavier bullet, say 570 or 600 grains, is more appropriate for the .505 caliber, IMHO.

quote:

Originally posted by jvw375:
The original load for the .505 was actually a 600-grain bullet at an alleged 2 150 fps. A friend of mine has an original Gibbs rifle with proof marks for the 600-grain bullet. I've actually fired it once or twice with 525-grain handloads.

Why was it changed to 525? Well, another friend who knows more than I do about old English rifles reckons recoil with 600-grain bullets was a bit too much of a good thing, and I'm inclined to believe him! It still hits with quite a punch, even with 525's at 2 200 or so, which was what two original loads did when we chronographed them.

The .505 cartridge has a helluva reputation but I'm not enamoured with the original rifles at all. They feel too much like hand cannons to me and an original pre-1939 .416 Rigby is more my idea of what a big-bore magazine rifle should look and handle like.

That Gibbs rifle is a early rare bird he has if it was stamped with a 600 grain load-- the one example I got to see was 90 grains of cordite/525.

Here is a good artical on the gibbs.

http://www.huntnetwork.net/mod...n/html/505magnum.pdf

Ed

The 525gr allow you to get up to the 2,300-2,400 fps range, which is not needed for a caliber that large. Load a 600 at 2,150 and you've got all you power and momentum you want.

The odd grains that the English use always botter me, till I read in Wikipedia about a gunia and why they use gunias, to pounds, real interisting. A troy ounse is 480 grains and if you use the fractions of troy ounse you come to the odd bullet weights, one troy pound is 5760 grain and 12 ounses is one troy pound, where 16 ounses is one Avou. pound and one avou.pound is 7000 grains. One avou. ounse is 437.5 grains, so the fractions 1/64, 1/32, 2/34 and so on give the odd grain weight

That is why they use 480 grain for the 450, 470 it is one troy ounse. 1/32 troy pound = 180 grain and 3/64 troy pound is 270 grain.

quote:

Originally posted by Biebs:
The 525gr allow you to get up to the 2,300-2,400 fps range, which is not needed for a caliber that large. Load a 600 at 2,150 and you've got all you power and momentum you want.

The 505 Gibbs is brutal at 2300 - 2400 fps.

2250 fps is about manageable.


jvw375
Yes, they are hand cannons. Mine is built with a huge stock, leather pad tacked onto the comb.

.

Ed, that is a great article! Thanks

This is all very interesting info. Rich suggested that 525 grains was used in a 505 caliber possibly due to import/export restrictions that may have been in place at one time or another. i.e. since you could not bring in, for example, a 458 cal gun to certain countries, 505 was used, and 525 grains of in a .505 caliber at a specific velocity was roughly equal in terms of performance to a favored banned bullet diameter/weight.

PD99, I do not have any recipes yet, I am just starting to poke around. I picked up some I4064 and plan to start with that. I have one box of 600 grain Woodleigh’s mentioned above, and about 100 or so 525 FMJ Woodleigh’s as well.

Very interesting about the troy ounce conversions. I suppose that explains some of the very odd weights on bullets (like the 357 mag shooting 158 grain bullets?).

Was sectional density the starting point for determining the weight of bullet that would be used for a given caliber? All of the standard (British) cartridge/bullet weight combinations from .375 up were between .3 and .35. The 525 505 and 535 500 Jeffrey are just under that at .294.

SD is actually exactly why I asked the question. It seemed to me that .3 is a good starting minimum for DG (I read that somewhere – “The Perfect Shot” Africa edition I think). By moving from a .458 in 500 grain to a .505 in 525 grain, I also go from a nice SD of .341 to a much lower SD of .294.

Seems to me that if one was to bump up to a 505 caliber, that it would be logical to try to also exploit a similar SD. Moving to 600 grain would yield a SD of .336.

Yet most manufactures make the 505 caliber bullets in 525 grain weights. I was wondering if there was a logic behind not going to a 600 grain bullet.

quote:

Originally posted by Rob H:
Yet most manufactures make the 505 caliber bullets in 525 grain weights. I was wondering if there was a logic behind not going to a 600 grain bullet.

Manufacturers will always stick with the Original factory bullet weight - at least at the start - because that is what guns would have been sighted in with. Changing bullet weight can alter the POI.

I'm glad Woodleigh and others upped the weight and produced the 600gn bullets.

.

I've even loaded 600gr in my 460 Guns & Ammo, a necked up and blown out 404 Jeffery. As long as you can get 2,050-2,200fps, you can take advantage of the bullet weight.

A 600g Woodleigh Softpoint or Solid at 2150 fps is just a little more than a 500 NE factory load (570g at 2100 fps), I've never heard too many complaints about a 500 NE's stopping power

I have handeled some original Gibbs bullets from pre WWI...495grn!! but the very first bullets to offer a steel jacket.

Gibbs obviously played around a bit and found what would and wouldn't work with his cartridge.

Biggest problem with many of the .505's on the market today is they are built with a magazine box that is too thin (the makers try and use the .416 rigby magazine box. One for the Gibbs should be .15" wider) This can cause the cartridges to pop out of the magazine at awkward moments and is particularly severe with nickeled cases like the Norma PH (which uses the 600grn woodleighs at 2100fps).

cordite and pressure
the 500 jeffery, with its smaller case and heavier bullet, using german flake powder 100% (no, there was never a cordite load, despite what some tyros stipulate) didn't suffer this problem.

a gibbs, with modern powder, and deliver well past spec vel at spec pressure

quote:

Originally posted by 303epps:
The odd grains that the English use always botter me, till I read in Wikipedia about a gunia and why they use gunias, to pounds, real interisting. A troy ounse is 480 grains and if you use the fractions of troy ounse you come to the odd bullet weights, one troy pound is 5760 grain and 12 ounses is one troy pound, where 16 ounses is one Avou. pound and one avou.pound is 7000 grains. One avou. ounse is 437.5 grains, so the fractions 1/64, 1/32, 2/34 and so on give the odd grain weight

I don't know if the Guinea is still used in English auctions, but I know for a fact it was still used well after legitimation of the metric pound.

When I was bidding in English auctions up until early 1982, my bids were still in Guineas, not Pounds. A Guinea was simple...one Pound plus one Shilling, or 252 Pence. The complication came in paying my man in London. He got 5% per Guinea or 12.6 Pence per Guinea for entering my bid, picking up and paying for the purchased goods, packaging them, and arranging for their shipment (usually by sea) to Canada. So, for every Guinea bid, I actually paid him 264.6 Pence or slightly over 22 Shillings, plus another 2.646 Pence currency exchange fee was charged to me by the Bank of Nova Scotia.

A grand total of 267.246 Pence per Pound, plus shipping.

And that just gives it in English currency of the day. The actual exchange rate into U.S. or Canadian dollars multiplied all that by normally somewhere within 10 or 20 cents either side of $2.65 per Pound in those days.

And people like me used to wonder why the English finally went metric with their currency.....just avoiding the errors in the math when doing international business must have saved everyone a fortune.

Now it is all a PITA again, for it has to go through being exchanged for Euros. Oy!!

And they still have horse reaces named XXXXXXX Guinea !!!!

Yes, they were confusing.

.

Jeff

Getting velocity within pressure for the gibbs is a nightmare with modern powders...maximum pressure is lower than for most double rifle and many handgun cartridges (27,000 PSI). Many loads that are within pressure don't obturate the case enough to cause an effective neck gas seal and the gas flows back around the neck and buckeles the shoulder... Most handloaders would never notice...they would load up ammo with something a little faster than Re 25 or Vit 170, H 5010 with the 525grn bullet...but if you do, you will be over pressure. This will not matter in a modern made rifle but may be a problem is some rifles built on CZ actions from the early 1980's or just post WWII on some belgian magnum actions.

Also many cases are not built to withstand high pressure...there is no requirement that the case head or primer pocket withsatand pressures over 35,000PSI. Depends where your brass comes from and what it is proofed tested to. As per specifications the case walls are typically very thin and so is the case head.

Re cases, I reckon Bell made the best cases of the one's I have seen.

Superb quality.

.

Norma have introduced empty 505 Gibbs cases for reloading in their 2011 catalogue (it's the largest empty case that they now sell); not sure about prices.

If cases are thin walled, does that mean they cannot be reloaded as many times, or does the low pressure lead to less stress and thus a longer case life?

Thin walled doesn't necessarily mean lower quality as a fair bit can depend on the brass quality itself.

Number of reloads can vary between gun (loads used), how much head space variation, how people re size the cases (ie can you get away with just neck resizing or do you have to FLR every time).

If you can get away with Neck resizing, this definitely adds to case life.

.

Ganyana,
I believe the pressure, cip, of the gibbs is just shy of 40k psi, but i could be wrong.

Modern powders can match that pressure, but require a filler - so we agree --

the OVER capacity of the gibbs, and even jeffery, is part of the reason why i designed and built the 500 AccRel --- a strong design constraint.

On sectional density, one can use a monometal bullet to allow about a 15% SD reduction with similar penetration. Barnes makes a good one, but the Cutting Edge bullets don't have one yet.

On loads, I would test loads that go up to 8000 ftlbs. See the review on RealGuns with the smaller capacity 500 Jeffrey:
http://www.realguns.com/archives/156.htm
http://www.realguns.com/archives/157.htm
http://www.realguns.com/Commentary/comar154.htm
http://www.realguns.com/Commentary/comar155.htm
Lots of good info there, especially first two.

One of the reasons, I went with the 500 Jeffery instead of the 505 Gibbs was lower case capacity. I can get to the load density I need without having to put 140g of powder in the case. Also the 570g Barnes TSX is a great bullet for the 500 Jeffery and it being monometal means it's longer and takes up more case volume, another plus. Hang fires are a real danger, use Federal 215 primers and make sure your case density is high!

OK, time to let it be known how ignorant I am...

Filler?

One needs to add filler to increase the volume of material in the firearm?

Few questions:
What purpose does this serve?
Is it put on top of the load, or mixed in with the powder prior to filling the case?
What material is used as filler?
Is this a big bore thing only?

filler..
think pillowstuffing.. or an ear plug
placed on top of the charge, between powder and bullet, to keep what is otherwise an underloaded charge (less than 85% in my book) from uneven burn or explosion

how important is doing this? it is a new concept to me - but I have only been reloading for a couple years now.

quote:

Originally posted by Rob H:
how important is doing this? it is a new concept to me - but I have only been reloading for a couple years now.

You need to read a little on 'detonation' in handloading. detonantion may occur in large capacity for bore cartridges, whether .243 or up to .505, where the powder is relatively slow and an underused case allows alot of space. Some special fast powders may be used for 'half-power' loads, otherwise, fill the case.

As I mentioned, if I had a 505Gibbs I would test it toward the high end, at least 7000-8000 ft lbs. The Gibbs is the granddaddy of bigbore cases, if lower power is desired, then a much smaller case-cartridge should be acquired. For example, stepping down, you could do a 500 Mbogo (.510" built on the 416 Rigby case, about a 15% capacity reduction, or a 500 AccRel, maybe a 25% capacity reduction. Both of those can equal the factory Gibbs power specs.

I'm sure a trade could be arranged, but I doubt that I have anything of close to equal value to what you've put in the Gibbs.

Use a powder that fills the case and you don't need to use fillers.

If you are not experienced in using fillers, find out from those in the know here before
using them.


Re "detonation", it is also referred to under other names including "flash over".

.

PS: whatever it is called, detonation is a very serious affair. The rifle literally explodes, with shooters waking up in a hospital or worse. Testing labs and machines have been blown up.

quote:

Originally posted by 416Tanzan:
PS: whatever it is called, detonation is a very serious affair. The rifle literally explodes, with shooters waking up in a hospital or worse. Testing labs and machines have been blown up.

Correct and worth mentioning.

I put the bit in my post in case he did a search on here or in Google.

quote:

Originally posted by Ganyana:

Biggest problem with many of the .505's on the market today is they are built with a magazine box that is too thin (the makers try and use the .416 rigby magazine box. One for the Gibbs should be .15" wider) This can cause the cartridges to pop out of the magazine at awkward moments and is particularly severe with nickeled cases like the Norma PH (which uses the 600grn woodleighs at 2100fps).

Thanks, Ganyana.
I have yet to find a .505 Gibbs with a proper box. Applicable to the 404 Jeffery History thread, about "perfection."

Ideal:
.505 Gibbs rim diameter of .6401574" maximum: box width at rear = 1.1945529"



The 404 Jeffery-based cartridges are about the only perfect ones with a case bigger in diameter than the .375 H&H.
The rest are just make-do's mostly.
Rare to find a perfect box.



Review of ideals:

Some ideal box widths at the rear according to CIP maximums:

.375 H&H rim diameter of .5318" and belt diameter of .5339" maximum: box width at rear = 1.86603 x 0.5339" = 0.99627"
This is more than enough, since manufactured brass is always smaller than the CIP max.

404 Jeffery head diameter of .5429" maximum: box width at rear = 1.86603 x 0.5429" = 1.01307"

.416 Rigby rim diameter of .5902" maximum: box width at rear = 1.1013309"

500 Jeffery head diameter (rebated rim abomination, rim diameter 0.5751968") head diameter of .6188976" maximun:
box width at rear: 1.86603 x .6188976 = 1.1548814"

.505 Gibbs rim diameter of .6401574" maximum: box width at rear = 1.1945529"

Forget about adding slop unless using the "rubber band method" to measure.

Using the max spec brass diameter will build in enough slop since the manufactured brass diameters are smaller than max spec anyway.

The 505 is hard for most to shoot accurately, unless the shooter is very experienced with handling recoil and the gun fit is proper. i have two, a cz 550 and a F Wells custom. The CZ doesnt fit me well, even after doing surgery on stock and barrel, and felt recoil is a lot worse than the Wells. CZ weighs about 11 lbs including scope, wells 11.5 with open sights.
No brakes, cs has 2 mercury recoil reducers, wells has none.
Re loads, my favorite is RL 15 109gr with 525 gr for 2200 fps and tolerable recoil. MUST USE FILLER with this load. Best is foam cut out to brass diameter, about 0.6" long, will take up all the empty space in this capacious case.
A safe balls-to-the walls load in my wells is IMR 7828 140 gr with 600 gr.bullet, which gives 2400 fps. No pressure signs at all, easy extraction, using HDS brass. Recoil is very stiff (for me), slows second shot, and I dont advocate this level of power unless T Rex is on the menu. A manageable load (without filler) is imr 4831, 135 gr with 525 gr barnes for 2300 fps.
Very effective load, plus the blue muzzle flash impresses the hell out of the spectators! Got >8 ft penetration with GS custom solids with this load, complete pass through big elephant.
Start with light loads and cast bullets at 1800 fps, gradually build up your confidence and recoil handling skills with practice. Dont shoot more than 6 full power loads/ session. NEVER shoot off the bench. Use shooting sticks or a standing butt. Avoid the lead sled; stock may fracture. recoil may be attenuated, but the butt will impact your cheek and remind you of Mike Tyson!
For me, once I build up recoil tolerance, its important to keep shooting at that recoil level fairly regularly. Put the rifle away for 6 months, and I am back to square one re flinching and lack of accuracy
I have loaded the 600 gr to 2550fps, but that is just not safe, so i wont give the load. Plus theres no earthly use for such a load.
Enjoy!

quote:

Originally posted by jeffeosso:
Ganyana,
I believe the pressure, cip, of the gibbs is just shy of 40k psi, but i could be wrong.

Nope, you are right.

.505 Gibbs CIP max average pressure allowed is 2700 bar which is about 39,150 PSI.

Interestingly, CZ marks their .505 Gibbs rifle with a roll stamp below the wood line on the left side of the action,
an action pressure limit for the .505 Gibbs with that big .640" case head:

3800 bar

that is 55,100 PSI