Then you'll have another 14 pounder you can't hunt with.

Nick,

Is there much difference between the 585 Nyati and 505 Gibbs case capacities?

Ray Atkinson will probaly jump in and talk about the advantage of the 505 Gibbs over the 50/585 is that you can get factory ammo for the 505 Gibbs

Mike

[ 10-01-2002, 08:06: Message edited by: Mike375 ]

Mike375,
I don't know shit about the .585's other than they are BIG!! I see loads of 180 grains and more so the barrels alone are gonna weigh in at 8 pounds+. I think they're great and I love the bullets but I can't for the life of me figure out how I can build one that I can "hunt" with, as I am accustomed to hunting.

Nick,

I am taking about using the 585 case for 416, 458 and 510 bores for PC as opposed to having a 505 Gibbs as I think in his case, since he has a 585 a 50/585 would be more practical for him than the 505 Gibbs and a 45/585 would be more practial than the 450 Rigby.

Mike

CARTRIDGE CAPACITY IN GRAINS OF WATER HELD

577 T.Rex. (German cases) 225.4

577 T.Rex. - (A-Squares Cases) 212.3
585 Nyati - (Bertram case) 187.3 - 184
505 Gibbs ------------------- 180.0

I'm not saying you're right or wrong, Mike. I'm just saying it's going to be heavier than the Gibbs, for sure, especially in .416 or .458.

[ 10-01-2002, 08:43: Message edited by: Nickudu ]

Nick,

So there you go, the 585 and 505 are the same capacity. In fact if those capacities are to the top of the neck, the 585 case might even be a tad smaller than the 505.

Since he has a 585 what pluses would the 505 offer over a 510/585

Mike

Take your .6400" case head and build your rifle.
Take your .6880" or .7500" case head and build your rifle. Which weighs more? Then fill them with cartridges. Which weighs more? You can build a Gibbs to 10 pounds that you can hunt with. The others won't cut it, IMHO.

Keep it short, Mikey ... I want to go to bed.

[ 10-01-2002, 08:52: Message edited by: Nickudu ]

But these blokd are doing the 585 with .640 case rim size.

That barrel you have on your 505 could have just as easily been chambered fora 510/585.

If PC has a 45, a 50 and 585 on the same case, everytime he has a couple of spare dollars he can buy some more Horneber brass without worryiong about which caliber. And of cousre he can have switch barrel without feeding concerns

Mike

Nick,

Someone might raise the issue of bolt thrust or chamber diameter, but whether the 505 or 585 case, you have these things running along in 2nd gear.

Mike

Set the rim size wherever you want, it's the case diameter that drives up the barrel weight. Can you imgaine the weight of a barrel which safely chambers a .585 case that is bored to only .416 or .458? You're talkin' heavy, man! Not to mention the extra powder burned just to match the .416 or .460 Weatherby velocities with a given bullet. I see what you're getting at, of course, but the results will be negative in my view. I'll see ya in the morning, my friend. I'm pooped.

Nick,

I cant see why a 45/585 needs to weigh more than a 460 or 458 Lott. The action is the same. Actually, with the same barrel contour it will weigh very slightly less because more metal came out of the chamber end of the barrel.

I am also guessing that "net cost of brass" would be lower for the 45/585 than it would be for either the 460 or 450 Rigby/Dakota because of such low pressures.

In addition, because he can do switch barrel, he saves on rifle costsings since he wants to have 45 and 50 as well as 416.

He could make his 585 a real bang up custom job and the 416, 45 and 50 could all be switch barrels on the other action and all running of Horneber brass.

In fact it is starting to sond more practical than a 6mm/06 and 30/06 switch barrel

Mike

I take from the take of .505 loading that there is a good deal of empty space in the .505 when loading to 'safe' origonal ballisitc proformance.

My question:
Say all you wanted out af a cartridge was the origonal 505 balistics, so you shorten a 505 case so all the empty space is removed. What affect would that have on pressures? Would they be sustanially higher then the same bullet and powder weight on the full lenght 505(with all that empty space or filler)?

KBGuns,

If you use appropriate loads the larger case will always develop lower maximum pressure than the smaller case for the same ballistics but a greater amount of powder will be used.

There can be some practical issues arise with accuracy and ignition.

For example let's compare the 460 Wby and 458 Winchester. A 458 will do about 2100 f/s with 500 grain bullets and maximum loads of say about 70 or 72 grains of 3031.

In theory, if we loaded the 460 Wby with about 95 grains of 4350, that would give us 2100 f/s with 500 grainers. Top loads for the 460 are at about 120 grains of 4350 with 500 grainers. So as you can imagine the pressure with 95 grains of 4350 would be super low.

However, we may run into problems with unburnt powder, accuracy problems etc. However, if we use 85 grains of 4064, then accuracy is great and everything is wonderful. That would probably give us pressure that is midway between the full 458 load of 3031 and the 95 grains of 4350 in the 460 Wby.

If we had a powder, could be similar to 4227, where if 70 grains of it in the 460 developed the ame peak pressure as does 70 grains of 3031 in the 458, then we have the same velocity and pressure for both the 458 and 460 with 500 grain bullets.

Using larger powder weights of slower powders in the bigger case to duplicate maximum ballistics from a smaller case would be similar to two cars going down the drag strip and each with the same speed at the end of the quarter. One car might tear off the line and then accelaration drop right away as it goes down the quarter mile. The other car might take off gently and maintain steady accelaration down the line and so finish at the same speed at the end of the quarter.

A Top Fuel dragster could post the same speed at the end of the quarter as a car that does 11 second for the quarter, but the Top Fuel could do it without the even the slightest squeal from the tyres at the start line. However, its speed at perhaps 100 yards would be less than the 11 second car going at full steam.

So in our example with the 458 and 460 both loaded to 2100 f/s, you might find that 10 inches up the barrel the 458 is traveling faster than the loaded back 460.

If you took a 375 H&H and used 4198 in it and loaded to maximum pressure, you would find that the velocity would be similar to a 375/06 loaded to maximum and you would also be using a similar weight of powder but the 375/06 might be using 3031 or similar. You could probably achieve similar results with 4227 in a 378 Wby. However, you might now run into hangfire problems.

In summary, if you wish to maintain a set of ballistics and reduce peak pressure, you need to use more powder.

Mike

[ 10-01-2002, 10:29: Message edited by: Mike375 ]

thank you Mike.

I have just started playing with Quick load, and am dazzeled by what a grain or 2 extra of power can do to the pressures, even in large cases.

Interory, then all the old large low pressure cartridge could be monderized and relize a signifigant power boost? Tho not in an origonal rifle, I would imagine.

Then power and pressure wise, how will the flegling .500 NINJA compair to the parrent .505 Gibbs?

KBGuns,

The Ninja looks to be a smaller case than the 505, so if all else is equal it will have less velocity potential than the 505 if both are loaded to the same pressure. Or to come another way, the Ninja will need more peak pressure than the 505 to achieve the same ballistics.

But again we enter the world of some practicality and personal desires.

For starters, the the 460 Wby necked up to 510 can already develop enough in velocity at perfectly normal pressures to exceed recoil limitations.

As I remember, the Ninja is about making a 50 caliber cartridge look like an overgrown 416 Rigby and also having a shorter over all length than the 505.

The 505 is about having the caliber with about the most charisma of all.

The 500 on the 460 case is the most practical.

Even though the 50 on the 460 case is much smaller than the 505, it might be quite possible to achieve velocities in it that exceed the 505, because of recoil and accuracy considerations.

Let us assume that the upper limit of recoil for a particular shooter is 2200 with 600 grain bullets. Now this will be a very easy load to do on a 50 based on the 460 since it will only be about 250 f/s under full loadings.. However, with the 505, we might find that such a velocity level is in hangfire territory. So we may be forced to go to a faster powder with less ignition problems and of course in the process wind up with less velocity than the 50 on the 460 case. Or we might be forced to go with a case full of very slow powder and also encounter unburnt powder and accuracy problems.

I am not saying that will be the actual case with the 505 and 50/460 but just using that to illustrate the practical considerations that arise when we limit ballistics due to recoil consideration as opposed to pressure considerations.

If we used the 50 BMG case we might have real problems doing 2200 with 600s because of hangfires and might have to go to shotgun style powders. However that would probably limit us to maybe 1500 or 1600 f/s.

So, if we have a top allowable velocity due to recoil considerations, for a very big case that velocity level maybe a "no go zone" due to accuracy and ignition problems.

Mike

[ 10-01-2002, 11:26: Message edited by: Mike375 ]

KBGuns,

I just wanted to note that the .500 Ninja was intended to be similar to the 500 A-Square, at least the case length. That 3.15" length of the 505 Gibbs is unnessesary long so it would make sense to chop it off to be around the same length as the 500 A-Square or the 416 Rigby. Of course, the .500 Ninja is a beltless cartridge so it would be an attractive alternative to the 500 A-Square. However, brass for the 505 is still very scare while the 460 WB brass is easily available so the 500 A-Square would make more sense to have in this case. Now that the 408 is becoming a reality so 505 brass may become cheaper and more available. I conceived the .500 Ninja before I know anything about the 408 so I did plan to go into a difficult route. Have fun.

[QUOTE]Originally posted by Mike375:
[QB]PC,

Mike,

you don't feel that the .416/.585 would be an overbore at all??.

I see your thinking and tend to agree that it would be the way to go on the Ultra Mag actions. You certainly could have that nice sharp shoulder on a 416/585. I wonder if the .458/.585 would not be a better performer. In Horneber cases one could get somewhere near or even surpass 3000 fps with a .500 grainer.

On the topic of the .505 gibbs I could only ever have that as a .505 gibbs for the nostalagia reasons you mentioned.

Ming,

I paid $2.08 US per case for my .585 brass via Robgunbuilder.

PC

If the 585 holds 185 grains of water, then necking it to 416 would give a case capacity to the bore area about like the 7mm Remington Magnum.

Mike

Thanks PC for the info. Apparently, the price he quoted for me was indeed in USD but a little bit more expensive than the 585 brass. Anyway, I will see if I can order some from him.

By the way, your 585 canon is awesome to look at. I will try have to have one built like that one of these days. Have fun my friend.

Cheers!
Ming

Mike well that would work then 416/585. Can you guess at what we might be able to drive a 400 gr and a 350 grainer at. If you were to build a .416/585 you might be better to shoot the new woodleigh 450 gr .416 bullets. They have a .372 Sectional Density & a BC of .402, and with the extra case capacity they may be driven to 2700 fps I am guessing and still have really low pressures (someone correct me if I am wrong).

When I think about this 450 gr .416 bullet would it not be a better penetrator than the original 400 gr .416 bullet, it could be driven to 2400 fpf from the .416 Rigby and maybe would work better for our African hunting buddies than the original loading ??

Thanks Ming for your kind comments, Rob got a group order together which made the .585 brass cheaper.

Take Care, PC.

PC,

If that Horneber brass is OK, I think you could get the 585/416 to give about the same velocity as the 300 Winchester with bullets of equal sectional density. A 330 grain 416 is the same SD as a 180 in 30, so about 3100 plus with a 330 grain bullet.

Should be good on roos across the flat country with the soft hollow point as per Speer 130 grain 308 Hollow Point style

Mike

Results would be very good, I would like a large cal bullet that was frangible enough that it would truly behave like a .50 gr ballistic tip and explode fully in the chest cavity. The only larger cal bullet I have seen come close to this is the .300 gr .458 sierra pro hunter. I dug one out the other week which did not quite make it through both rear hams (45/70 @ 2150 fps 50 or so yards), it is toatlly mangled and looks like a mighty boy suzuki ute would after colliding with a kenworth . Next time I get a digital camera I'll send you a pic of it.

Ming,

Sound like agood project to me. I personally dislike belts. Since it will be awhile before I will be building my .50, it just may be a Ninja.

Wells Did several 585n by X.. I think they do a 585x500, 585X475, 585x450, and I think a 585x416.

jeffe

Mingo, what actions would your Ninja fit into? Would you make rifles in this caliber for others?

Casey

A couple quick notes:

Two things that do really well at stamping out hangfires in .505 Gibbs cases are 1) IMR 5010 powder, 145 gr. of which completely fills the case behind a 700 gr. bullet for only 2075 fps (pop!), and 2) filler. I have just gotten to try some cylindrical polyolefin (?) foam from Home Depot of slightly more than 1/2" dia., and I am completely satisfied. NO hangfires either with full loads or faster powder (WC 852 (slow)) and foam.

In the current issue of Handloader Ross Seyfried says not to use foam filler and reports that he knows of two double rifles have been ruined by it. He did not say what happened, and in the same article he does recommend the use of Dacron pillow stuffing filler. Evidently the problem is not with the use of filler (not recommmended by A-Square), but the KIND of filler.

Has anybody besides me contemplated the use of those blackpowder sabots with heavyweight handgun bullets in them in (heh, heh) out of one of the .510 cartridges? Imagine a .505 Gibbs launching a 300 grain .45 bullet. As long as there is not an extreme requirement for accuracy and the sabot survives, this sounds like terrific solution to extracting the power from the .505 Gibbs case and applying it to a smaller diameter bullet. I had not thought of using such a load for hunting, but for fun shooting. I would not chronograph the load without consideration for protecting the chronograph from the sabot.

Jeffesso how did those rifles perfrom, velocities etc. Is there a link one gan go to to get some more imfo ??

Thanks Jeffo, I tell you what mate there is not much that has not already been done !!