Gentlemen

I have for quite some time been working on making a good solid for my .500 Jeffery.
About tree years ago I made the first version of my CPS (Cup Point Solid)
They worked fine in tests and penetrated good in phone books.
I have in collaboration with a custom bullet company made this latest design.
I have not tested this latest design yet.

They are made in pure Copper

Cal. 510 for my .500 Jeffery
Weight: 550 grn
Bullet OAL: 33,20mm
Cup dia: 9mm

What do you think?

Cheers,

André

Pretty sweet! With the rounded edge, it most likely would feed well in a turn-bolt...something one of my guns won't consistantly do with NF's. I imagine those rounds out of a 500 Jeff have some serious thumping power.

Nice job....a very good design.

Gary
DRSS
NRA Lifer
SCI
DSC

Thanks for the kind words.
They are designed to feed smooth in a mauser style action.
The NF where made for Ray and for his double I think.
With a good death crimp there should be NO edges I expect a super smooth feed.
I will load up some ASAP.

Cheers,

André

/

Jeffery,
They certainly look good, but I wonder if the cutting shoulder on the NF isn't a real plus in cutting a cookie cutter hole on entrance, it seems to be, as I know it lets a tremoundous amount of blood out...I have tweeked all my bolt guns to feed the NFs, so they work fine..some factory and custom rifles won't feed them.

What would you have to do to get a cutting shoulder on your bullet? or is that practical? Also I realize there is pro and con on the cutting wad cutter type shoulder, I am of the school it works great.

JDM,

Very nice bullet. Based on my experience with North Fork cup points on game, I would consider making the cup a bit deeper because essentially all the expansion I have gotten is down to the bottom of the cup. The cup should be deep enough that the bullet expands beyond nominal bullet diameter (.510") or you would be just as well off to use an FN solid.

I also note that your bullet is a grooved design rather than a driving band design. A driving band design takes more machine time, more precision and is more expensive. But the reward that you get is less barrel friction, less barrel heat, less fouling, more velocity, and the first driving band acts as the cutting shoulder that Ray mentioned above.

All that being said, I am sure you could use your bullet as shown above on 1000 buffalo and never feel it was inadequate.

quote:

Originally posted by 500grains:
JDM,

Very nice bullet. Based on my experience with North Fork cup points on game, I would consider making the cup a bit deeper because essentially all the expansion I have gotten is down to the bottom of the cup. The cup should be deep enough that the bullet expands beyond nominal bullet diameter (.510") or you would be just as well off to use an FN solid.

I also note that your bullet is a grooved design rather than a driving band design. A driving band design takes more machine time, more precision and is more expensive. But the reward that you get is less barrel friction, less barrel heat, less fouling, more velocity, and the first driving band acts as the cutting shoulder that Ray mentioned above.

All that being said, I am sure you could use your bullet as shown above on 1000 buffalo and never feel it was inadequate.

x2

I have read many disscusions here about bullet cavitation in game animals.. If the bullet cavitates how is the first driving band going to act as a cutting shpulder... In handgun bullets it has been proven that the semi wad cutter shoulder does not come in cntact, because of cavitation....

Beautiful work indeed! It would be interesting to see your test results (velocity, penetration, etc)

Looks like lots of people love the .500's these days.

Maybe we few tinkerers should have a good old fashioned bullet roundup and competition. I'm sure the big guns would want to contrubute so as not to be left out of the fun!

What would be the venue? What kind of tests? Who would make the special trophy?

I'm In!!!

Great bullet!

I would buy some of those if they were commercially available.

quote:

Originally posted by jwp475:
I have read many disscusions here about bullet cavitation in game animals.. If the bullet cavitates how is the first driving band going to act as a cutting shpulder... In handgun bullets it has been proven that the semi wad cutter shoulder does not come in cntact, because of cavitation....

x2

/

Gentlemen

Thanks for the kind words and the constructive criticism.

Like many of you I am interested in getting the best bullet out there, even if that means that I have to make it my self.

My design is a clone of many bullets, I am however willing to make changes to get the best end result.

Lets discuss what could be made better and the DO IT.

Lets keep developing the CPS bullet.

When the design is done, it may never be, I will have a large batch made, you can get in on that without me making a profit. So mrlexma you can have some.

I like Grooves better then drive bands. They make it possible to get a nice smooth edge and death crimp.
Originally the grooves had a angle, it looked cool and I might ad that feature next time. It also gave a nice soft bend to the case.
Here are some pictures of those grooves.

Making the cup deeper makes sense.

Alf
Thanks for the kudos I respect your opinion very much.
I wanted to design a stabile bullet but do not know all the stuff you do. I do however know that a flat solid will keep its path better then a round one. When hitting a big bone in a elephant or buffalo
I also wanted a solid that left more energy in the animal and not so much in the ground or tree after leaving the animal, the cup and a slight expansion will take care of this. I still want the bullet to go true, if possible. Jeffery or Gibbs velocities, 2400 fps should take care of this.

Making a sharp shoulder on the bullet is no problem, here is a picture of one with a shoulder with a sharp edge, just like on the Impala bullet. I do however want to secure a smooth feed in most rifles and like pointed out by jwp475 it might not even make a difference. It will however give an edge that could result in a bad feed.

Cheers,

André

André, count me in when the time is right!

I was very disappointed when Mike at NF told me that he would never be able to market .510" bullets economically. It's apparently a raw materials problem.

I also prefer the grooved bullet design for crimping purposes in a bolt rifle. All you need to do is look at the dents in the front of the magazine well of my .500 A2 to see the need for a "death crimp" as you say.

It seems to me that your bullet design would translate into a good FN solid, too. Just eliminate the cup point and make it a flat meplat. Like the Barnes 570 grain FN Banded Solid, only a bit lighter.

Then use the cup nose for buff and the solid for elephant (and hippo). Seems to me it wouldn't take very much tinkering to get the two bullets to shoot to the same point of aim. Just what the doctor ordered!

quote:

Originally posted by 500grains:


I also note that your bullet is a grooved design rather than a driving band design. A driving band design takes more machine time, more precision and is more expensive. But the reward that you get is less barrel friction, less barrel heat, less fouling, more velocity, and the first driving band acts as the cutting shoulder that Ray mentioned above.

Absolutely correct!

A cutting shoulder only works on stuff like paper, cardboard and plywood. Having used otherwise identical solids, with and without cutting shoulders on game, the entrance holes of both are the same and, the sharp edged hole that is seen with FNs, is caused by the flat meplat. Shoot round nosed solids with a cutting shoulder on game, to prove this to yourself. The holes are not sharp edged on game, only on paper.

Alf,
CG position and its contribution to the overturning moment is only an issue when the bullet length / caliber /twist ratio passes a certain point. To that end, we make boattails as long as they need to be. See the partial selection below. The exception is the 180gr 308, second from left, that is for very specific applications.

/

Gerard

quote:

A cutting shoulder only works on stuff like paper, cardboard and plywood. Having used otherwise identical solids, with and without cutting shoulders on game, the entrance holes of both are the same and, the sharp edged hole that is seen with FNs, is caused by the flat meplat. Shoot round nosed solids with a cutting shoulder on game, to prove this to yourself. The holes are not sharp edged on game, only on paper.

Thanks for that information.
I want a problem free and smooth feed. No need making a bullets that might jam in a dangerous situation.
What do you think about the cup point design?

PS Copper is KING

Cheers,

André

Alf,
You are right and I was not referring to gyroscopic stability during penetration in the tissue.

Posted 24 May 2007 22:12
I think that the most difficult part of the terminal ballistics event is getting the bullet to transition from air to tissue without destabilising. If the bullet can be made to penetrate the target, along the line of the flight path, without the bullet axis deflecting, for just one or two bullet lengths, the battle is won.

Even if the angle of incidence is extreme, such as on the angled shot described by Doc, if the bullet transitions correctly, the result is good. With a bullet that is yawing with a low gyroscopic stability factor, there is little chance of a good transition. A high angle of attack on a bullet, combined with a high angle of incidence when it strikes, is guaranteed to spoil your day.

For good transition the SF and CG is of great importance and CG carries over to in target stability.

What I have noticed is with a cutting shoulder you get a clean round entrance hole and shaved hair for about an inch around it..That give me the impression that it works better with a cutting shoulder...I know it spurts a lot of blood out.

I won't argue with the experts but I will continue to use the simi wadcutter type bullet as it appears more effective to me. It worked on Keiths 44 and 45s and it performs exceeding well in all my rifles..

You could be 100% correct, but I have shot a lot of stuff with different bullets and I still believe in that cutting shoulder.

The only bullet with a true cutting shoulder was the Bridger bullets flat nose solid and it performed better than any true solid that I have ever use. However its a moot point as Bridgers are no longer available.

I posted a photo of an entrance wound with an impala bullet on a Cape Eland just a short time back. Here's a link:

https://forums.accuratereloading.com/eve/forums/a/tpc/f/...=710105647#710105647

The photo shows what Ray is describing and is my experience. Gerard, I haven't seen the same effect when using Nosler Partitions in my .375 on African Game.

Andre,
Looks very nice.
I wonder if that nose portion is full caliber and full bearing on the rifling or does it taper some in the area of the nose that looks straight sided?
CIP throat for the 500 Jeffery has no parallel-sided freebore and is just .511" at the start and then tapers with a leade angle of 0-degrees-47'-53".

Most all of the nostalgic cartridge rifles have tight throats like that and had those bullets with short, tapering nose sections.

Does your rifle have the tight CIP throat for the 500 Jeffery or is it different?

You have certainly overcome this little bit of nostalgia with a radical new bullet for the 500 Jeffery.
Good job.

/

how about just adding a cup and maybe a semiboat tail to the barnes or A2

If the metal is too hard maybe just copy the design with copper and add the cup.

Well for one I want a copper bullet, and I want a cup point, and I want a boat tail.
The .500 Jeffery is a fast BIG bore. I want a solid that slows down a bit and delivers more energy in the animal BUT still penetrates deep/goes true.
I am hoping that the cup point feature will provide this.
This design might not work in other calibres with lower velocities.

Who will help me test these with American powder? I am loading some with Vithavouri N140 about 118-120 grn.
If I get the time I will make a elephant sandwich. 2" of Weet newspapers Cow leg bones and more weet newspapers to catch the bullet. Sorry I do not have any balistic gue

RIP

The front of the bullet is a bore rider 12,75mm The area where the grooves are is 12,91. Looks like this when fires into phone books. This picture is on the first design, where the cup is only 5.45mm.

Cheers,

André

Gentlemen

How about making a cup/hole in the back of the bullet.
This will in combination with a slight expansion of the front make the bullet heavy in the nose and the direction more controlled by the front of the bullet.
Due to cups in the front and the back the CG of the bullet will be in the middle section, and after hitting the target medium the bullet will hopefully expand a bit, making the bullet more front heavy and the direction controlled by the more heavy front.
Maybe drivebands are better then my design, if so I will apply those instead of the grooves.
I think the front cup will need to be a bit deeper in order to get a little expansion

Any input?

Cheers,

André

But will the cup on the base possibly expand irregularly before it exits the bore, and cause accuracy problems? That base would be facing pressures of 3300 bar (the CIP max ave = 47,850 psi for 500 Jeffery) and more in some other applications undoubtedly, and material variabilities might lead to asymmetric base obturation. Even a slight asymmetry might be a very bad thing at the base of the bullet.

The CIP throat for the 500 Jeffery is merely a leade tapering from .511" to .500" over the course of .410" from the start.

Your bullet nose of .502" diameter should be clear in that throat for only .336" before it is knocking on the lands.

If you can close the bolt on that 500 Jeffery with the bullet crimped on the first groove, then your throat is more generous than the CIP minimum throat.

Something like the 500 A-Square has .400" of parallel-sided freebore length of .511" diameter, then a 1-degree leade begins. Your bullet shoud certainly work there and might be crimped further toward the base if magazine box length allows, and if feeding allows.

all objects exceeding the speed of sound have hypersonic airflow at near right angles to surface vs airflow

there is some discussion as to the effect of this with penetration... as there is a hypersonic air bubble infront of the bullet, that has ALOT of energy...

"Cavitation" .. happens at 40 MPH in torpedos. There is where the russians came up with "super cavitation" to allow a torpedo to go faster through water by displacing the water infront ...

water is ~800times more dense than air...

oh, yeah, torpedos dont' rotate, it is purely a matter of nose shape.


oh well, that will probably start more arguements than politics

jeffe

polite conversation should never include religion, politics and terminal performance...

does anyone care to update wikipedia....

http://en.wikipedia.org/wiki/Terminal_ballistics

/

perhaps it is "terms" that are causing the issue here
I used the scientific and physics term cavitation to describe when gas bubbles are released from a fluid.

alf may be discussion the MEDICAL term of causing a void in a space.

these terms are NOT interchangable, and are entirely unrelated.

btw, nobert is discussing bubbles being released, reducing the density of the fluid in front of an object

cavitation is the release of BUBBLES from a liquid, guys...
has NOTHING to do with bullets, and in fact, myth busters proved, beyond the shadow of a doubt, slow bullets at slow twist "penetrate" deeper in water than faster bullets at fast twist... with lead slugs from a muzzle loader going into water, and 50 bmg bullets turning into gravel

quote:

Originally posted by ALF:
Jeffeosso:

Can I ask you a question, just to be polite

Do you get holes ie cavities in animals when they are shot with round balls, pointed bullets, flatnosed bullets,even square bullets as represented by fragments from bombs etc.

If the answer is yes then it means that all of these shapes cavitated, how else would they penetrate.

Why thanks for asking alf. If i shoot a WAX blob and it makes a hole, of whatever shape, does it cavitate? The answer to your question, and mine, is that "cavitation" has nothing to do with this. Cavitation is The sudden formation and collapse of low-pressure bubbles in liquids by means of mechanical forces, such as those resulting from rotation of a marine propeller. Bullets do not cause low pressure... there is no vapor IN MEANINGFUL CONTENT released

quote:

So much for shape and the nose shape

Alf, you kow better, and I enjoy these discussions... a bow wave, which is created infront of ALL hypersonic objects, is the first thing to impact an animal ...

quote:

But what about Supercavitation or just simply cavitation in water?

cavitation is the formation of bubbles, super cavitation is the "super" formation of bubbles IMMEDIATELY infront of a torpedo, it happens at about 40MPH...

quote:

Is this phenomenon shape dependent?

without a doubt, as the russions or nobert

quote:

No it is not in fact the laws of hydomechanics claim that cavitation is only dependent on the vapour pressure of the particular fluid in which boundry flow is evoked Nothing else !

confusing the issue. If there were no gas vapor pressure (trapped gas) there would be no cavitation. EXACTLY the same as pure water is a great insulator, until impurities are added (electolyts)

quote:

The cavitation number is an expression of this phenomenon and it is dependent on the fluids vapour pressure, the local absolute pressure of the fluid and the flow velocity, that's it, nothing about shape etc.

No alf, you are PURPOSLY confusing a potential of a fluid with a mechincal action on the fluid... the caviation number is that the fluid CAN release a gas, not that it does. Exactly like "amps" of a 12 volt car battery... 600amp is good for cool starts, 750amp is far better for cold .. NEITHER releases the watts potential instantly... this is called an bomb

quote:

So again if we place shapes, any shape in fact in flowing fluid ( of sufficient velocity) cavitation will occur if the pressure in the boundry layer drops to the vapour pressure of that particular fluid and the determinant is the vapour pressure not the shape of the object in the flow field.

confusing potential with mechcanical action again. the fluid has the SAME cavitation number, if there's a bullet in it or not... but, of course, your experiement has a top end speed boundary layer, that when exceed, breaks the measurement..

quote:

So should you shoot a round ball into a pool of water, or a pointed bullet or a FN bullet all of these bullets will form cavities,

yes, we agree

quote:

by exactly the same rule;

yes, but different VALUES for the rules

quote:

all that is going to differ is the inception point of the cavity on the shape,

both incorrect (speed and shape change "cavity") which changes the SPECIFIC denisty of the material in the way (your amorphous tissue arguement)

quote:

usually the largest diameter of the round or pointed bullet and in the case of the FN bullet at the edge of the meplat
....... and here lies the difference and also why the FN is subjected to less drag than the other shapes.

but you just said shape doesn't matter?

Alf, let's face it, an aerodymanic car slips throw the air, the fog, and the rain with less effort spent than a square "truck" .. and a russian torpedo, with it's nose disk, goes 30% faster through water than without.

but wait, the supercavition of the torpedo is 100% due to the nose shape, which makes gas bubbles form within "solid" water...

with all due respect, its physical force on solids (or semi solids) that make wound cavities.. and the same forces apply to air... go pick up the speer reloading manual with the highspeed of the bullet going through the air.

or look at any highspeed photos of a jet making the transonic transition...

it's clear and present...

ah, we'll never agree, but I will always state that "supercaivition" as used in science, has little to do with penetration of a bullet, as the speed of a bullet is above the upper limit of most materials to be a significant force.

I too saw that particular myth busters, but to claim that the mythbusters prove anything beyond a doubt is stretching the truth at best. Their "scientific methods" are lacking, to use a euphemism. It makes for good T.V., but I doubt the scientific community accredits them with anything more than reinvigorating the history channel. That said, I'm sure that someone else prior to those chaps proved the same thing or something similar.

Sorry to interrupt the cavition conversation.

Discovery Channel, not History Channel.

Back to Andre's proposed "cup-base-cup-point" bullet for the 500 Jeffery please:

Good or bad idea?

quote:

Originally posted by RIP:
Discovery Channel, not History Channel.

Back to Andre's proposed "cup-base-cup-point" bullet for the 500 Jeffery please:

Good or bad idea?

Tastes Great but Less Filling.

quote:

Originally posted by Macifej:

quote:

Originally posted by RIP:
Discovery Channel, not History Channel.

Back to Andre's proposed "cup-base-cup-point" bullet for the 500 Jeffery please:

Good or bad idea?

Tastes Great but Less Filling.

Fork!

Gentlemen

This thread is way off the hock.
Seems like I presented my new design at the wrong time.
Why don't we start a thread with general bullet politics and then I will start a new one where we can discuss my new design.
I am asking questions that other members don't even have the curtsey to comment on, BUT general comments are made about torpedoes! I feel like I am at a dinner where people are talking over my head and not answering questions when I try to join the conversation. This is ungentlemen like behavior.
I would like to hear what skilled and knowledgeable people have to contribute to my design.
When we find a consensus on the design I will make a another batch and members interested can test them.
That way we can end up with a great bullet.

Cheers,

André

You are right. Back on topic...

The design is great but a deeper cone I would desire.

Now they need a name...Expanding penetrator Energy Transfer Bullet or E.P.E.T.

Question...does a bore rider have more inherent accuracy? With the front portion sliding on the tips of the rifling does that keep the bullet more true?

when results can be repeated, and are documented, and subject to peer review, it is far more scientific than some other of our penetration "tests"

Andre, great looking bullets, however your design raises many questions of terminal performance, expansion, and penetration. If you wanted merely a 10 post thread on the bullets looks/design, there is a bullet making forum.

but, if you want to discuss the various opinions on how bullets perform, this appears to be the correct forum.

LOL .. myth busters not proving anything? should we apply that to 99% of the "facts" running around the internet and AR, we would feel nothing has ever been proven, period

quote:

Originally posted by boom stick:
You are right. Back on topic...
...Question...does a bore rider have more inherent accuracy? With the front portion sliding on the tips of the rifling does that keep the bullet more true?

ha!! aint that the same thing as being off topic on penetration??

They look real good. The next question is how the work on game. Are they going to have pedas Like Barns? bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb