Bullet Swagging

[TnTom]

When a jacketed bullet is made (hpbt) where does the excess accumulate"? At the meplat or bullet base.

Is the ogive a "distance"? I'm thinking it begins at the end of the body diameter and ends at the tip of the cone?

Is datum a circle somewhere along the ogive? Can datum be any circle along that distance or ogive? Ideally would it be the circle the same diameter of that point in the chamber where the free bore ends and the rifling begins?

Who could I speak to and clear up some daunting questions that I will spare everyone here from?

I;m trying to clear up in my head some variations I see in a group of bullets. Im thinking these "competition" bullets are coming out of mutiple cavities at least. It has nothing to do directly with the meplat that could be cured by trimming it.

When a jacket is joined to a core can the core move as its swagged and reflect variation Im detecting when I measure from a point on the ogive the base of the bullet?

 

[Pete Wass]

Measuring from point to base

When a jacketed bullet is made (hpbt) where does the excess accumulate"? At the meplat or bullet base.

Is the ogive a "distance"? I'm thinking it begins at the end of the body diameter and ends at the tip of the cone?

Is datum a circle somewhere along the ogive? Can datum be any circle along that distance or ogive? Ideally would it be the circle the same diameter of that point in the chamber where the free bore ends and the rifling begins?

Who could I speak to and clear up some daunting questions that I will spare everyone here from?

I;m trying to clear up in my head some variations I see in a group of bullets. Im thinking these "competition" bullets are coming out of mutiple cavities at least. It has nothing to do directly with the meplat that could be cured by trimming it.

When a jacket is joined to a core can the core move as its swagged and reflect variation Im detecting when I measure from a point on the ogive the base of the bullet?

Is useless information because jackets are somewnat irregular once bullets are pointed up. A better method is to measure from the base of the bullet to the beginning of the ogive just above the body of the bullet, from my experience

 

[Gerry]

Please clearify each question.
Your posting a complex question actually 4 or more.
Each question will be answered if properly asked.
I tried just a simple complex question like yours and it received many negative answers.
Putting it simply some people can't read your thoughts''
Take them one at a time.
The engineering therory is a complex problem.
drawings would be needed to show some of answers to one question.
A complete
thread was just posted on bullet making i'm sure most of your question could be thought out with careful reading.
Take it one step at a time and i'm sure you will get the answers
Not being a smart a$$ .

 

[J. Valentine]

When a jacketed bullet is made (hpbt) where does the excess accumulate"? At the meplat or bullet base.

Answer . There is no excess. The core is seated into the base and body of the open jacket and when point formed the front part of the core is reduced in shape to extrude forward to fill the ogive.

Is the ogive a "distance"? I'm thinking it begins at the end of the body diameter and ends at the tip of the cone?

The ogive is defined as a curve starting at a point on the bullet shank where the caliber diameter starts to drop down and continues forward to end at the edge of the nose Meplat.
When refering to the ogive of a bullet you are talking about the whole circular cone and its fdull profile shape which in reality the drawing curve will extend past the meplat to a point. However most bullets can not come to a sharp needle point . So it is truncated back to some degree.

Is datum a circle somewhere along the ogive? Can datum be any circle along that distance or ogive? Ideally would it be the circle the same diameter of that point in the chamber where the free bore ends and the rifling begins?

Answer . I think you are refering to the spot on the ogive that you choose to measure from the base to. Base to datum.


Who could I speak to and clear up some daunting questions that I will spare everyone here from?

I;m trying to clear up in my head some variations I see in a group of bullets. Im thinking these "competition" bullets are coming out of mutiple cavities at least. It has nothing to do directly with the meplat that could be cured by trimming it.

Anything is possible in bullet making but there is many other variables far worse than bullets like wind for just one.



When a jacket is joined to a core can the core move as its swagged and reflect variation Im detecting when I measure from a point on the ogive the base of the bullet?
Answer .
If you look at photos of freshly swaged bullets you will see in many cases especially over 10 caliber ogives, many small wrinkles in the ogive surface.
This causes fine errors in measurements from base to datum because contrary to belief the ogive is not a perfect curve and it varies a bit each bullet .
It is quite rediculous to believe you can accurately measure to tenths of a thousanth in this way. Temperature changes alone would preclude it being consistant.
The slight differences you are seeing is not your accuracy problem all bullets are like that to some degree some better some worse.
I have posted a picture of bullets made by a top bullet maker and you can see the wrinkles in the bullet ogives . This is quite normal and happens all the time. If you look closely you will see what I mean.
If a bullet is made properly the core will extrude forward to fill the ogive very consistantly . However a very rough and inconsistant operator on the press could add to length inconsistancies.
However a very slight length difference may have no effect on accuracy at all.
The concentricity of the jacket is more important and it is very difficult to test that accurately once the bullet is made.

 

[Gerry]

Correct on answer J Valentine, No excess.
When the bullet is pointed there is a shape change Only.
The mechanical forces are complex that are generated inside the bullet
The forces go down other forces go up and to the side, and some are on an angle . Its not a straight up motion . there is reverse tension exerted on the bullet. The pressures inside the die are in the thousands of pounds if you could measure it. The standard reloading press is capable of delivering chamber pressures. I hope this helps along with your post.

 

[Gerry]

Yes the ogive Pronounced {ojive} Has a distance ,
It is the curve fron the taper on the body that can be mesured.
{ Basic Geometry} They start from different places on the taper of the body. A 6 ogive is or has a steeper angle then a 10 ogive on a low drag.
I'll let others comment on my nichels worth.

 

[R. G. Robinett]

When a jacketed bullet is made (hpbt) where does the excess accumulate"? At the meplat or bullet base.

Answer . There is no excess. The core is seated into the base and body of the open jacket and when point formed the front part of the core is reduced in shape to extrude forward to fill the ogive.

Is the ogive a "distance"? I'm thinking it begins at the end of the body diameter and ends at the tip of the cone?

The ogive is defined as a curve starting at a point on the bullet shank where the caliber diameter starts to drop down and continues forward to end at the edge of the nose Meplat.
When refering to the ogive of a bullet you are talking about the whole circular cone and its fdull profile shape which in reality the drawing curve will extend past the meplat to a point. However most bullets can not come to a sharp needle point . So it is truncated back to some degree.

Is datum a circle somewhere along the ogive? Can datum be any circle along that distance or ogive? Ideally would it be the circle the same diameter of that point in the chamber where the free bore ends and the rifling begins?

Answer . I think you are refering to the spot on the ogive that you choose to measure from the base to. Base to datum.


Who could I speak to and clear up some daunting questions that I will spare everyone here from?

I;m trying to clear up in my head some variations I see in a group of bullets. Im thinking these "competition" bullets are coming out of mutiple cavities at least. It has nothing to do directly with the meplat that could be cured by trimming it.

Anything is possible in bullet making but there is many other variables far worse than bullets like wind for just one.



When a jacket is joined to a core can the core move as its swagged and reflect variation Im detecting when I measure from a point on the ogive the base of the bullet?
Answer .
If you look at photos of freshly swaged bullets you will see in many cases especially over 10 caliber ogives, many small wrinkles in the ogive surface.
This causes fine errors in measurements from base to datum because contrary to belief the ogive is not a perfect curve and it varies a bit each bullet .
It is quite rediculous to believe you can accurately measure to tenths of a thousanth in this way. Temperature changes alone would preclude it being consistant.
The slight differences you are seeing is not your accuracy problem all bullets are like that to some degree some better some worse.
I have posted a picture of bullets made by a top bullet maker and you can see the wrinkles in the bullet ogives . This is quite normal and happens all the time. If you look closely you will see what I mean.
If a bullet is made properly the core will extrude forward to fill the ogive very consistantly . However a very rough and inconsistant operator on the press could add to length inconsistancies.
However a very slight length difference may have no effect on accuracy at all.
The concentricity of the jacket is more important and it is very difficult to test that accurately once the bullet is made.

Well done, Mr. Valentine.

Bullet making isn't 'rocket science': it's simply the common sense use of good tooling to convert lead-wire and excellent jackets into bullets. To learn the fundamentals of bullet making, one of the BEST reads remains the description, by Mike Walker and Emory Tooly, published in THE ACCURATE RIFLE, by Warren Page, Winchester Press, 1973, in chapter 11, The Supremely Accurate Bullet . . . some things haven't changed since Biehler & Astles, during the late 1940's, conceived the single cavity, 'swaging-up' process of bullet making. Keep 'em ON the X! RG

 

[Gerry]

Great post RG Robinett'
It's not rocket science and a long post was and still is on the board about bullet making.
I guess he's thinking in the technical aspect of forming/
After the bullets core is swaged into the seating die.
It has a cylinder shape .
On the point up operation the cored jacket is cold formed into
It final shape. The amount of lube on the jacket has some effect on ogive but very very little.
In factory bullets the point die is set to leave a small meplet on the top.
That is caused by a small part of the jacket material entering the top of the die in the knock out pin hole. It is set pretty close as to not leave too large a meplet.
The reason being posative ejection from the dies on automated equipment.
The point is the same , the bodys are different lenghts.
Remember factory bullets are run on automated machines and not one at a time .
Heat also comes into play. as the die heats up it expands a tiny bit .
This also has a,limited factor in the bullet shape .
It's very very slight. unless something goes wrong.

 

[TnTom]

Im trying to identify the cause and effect of this .018" variation in base to ogive. Disregard any error in measurement, there isn't any.

The bullet is located in the bushing at a point .214 diameter.

100 bullets varied from 1.040" to 1.058"

group (1) 3 @ 1.040
group (2) 5 @ 1.042
group (3) 13 @ 1.044
group (4) 36 @ 1.046
group (5) 28 @ 1.049
group (6) 12 @ 1.051
group (7) 3 @ 1.058

What causes this condition in the manufacturing process.
what effect does it have on the path of the bullet.

Is it an indication that the bullets aren't of a quality level that is being implied as a "Competition" level.

When I load and shoot bullets from one group for ex. group 6 (all within .0005" of 1.051) my 5 shot group is good, .330

Repeating the process with bullets from group 2 again the 5 shot group is good .400".

There is a variation in the group center or point of impact by .500".

I've noticed this with lots from both Seirra and Nosler. Does this condition exist all all swagged bullets. I would think that "custom" would not.

I'd like to be able to use bullets from a lot that is more like within .002" - .003" maximum variation ogive to base.

Any recommendation?

thanks Tom

 

[Gerry]

Ok i see what your asking"
Like i have said before a picture is worth a thousand words.
The difference your seeing is length of the bullet.
The shorter bullets will have less bearing surface.
Actually for mass produced bullets thats pretty good.
If you change your oal to fit the proper seating depth in your rifle
you should get good group with the other bullets.
The best thing to do is select and sort them , then change seating to accomidate this. We use shims on our straight line seating dies that allow us to change seating depth at will.
If you seated all of them long into the rifling like some do.
The problem is solved That also raises pressures.
If you do want to use on specific depth like a lot of us do.
Then buy hand swaged bullets . Theres a big differance.
The hand swaged bullets are made much slower and are more uniform then most factory bullets.
Barts , Robbinett Euber are a few of the brands.
I think you will find that a good lot of Bergers will also fit your needs.
contact Eric Stecker and ask Maybe a certain lot is running really close.

 

[J. Valentine]

Well done, Mr. Valentine.

Bullet making isn't 'rocket science': it's simply the common sense use of good tooling to convert lead-wire and excellent jackets into bullets. To learn the fundamentals of bullet making, one of the BEST reads remains the description, by Mike Walker and Emory Tooly, published in THE ACCURATE RIFLE, by Warren Page, Winchester Press, 1973, in chapter 11, The Supremely Accurate Bullet . . . some things haven't changed since Biehler & Astles, during the late 1940's, conceived the single cavity, 'swaging-up' process of bullet making. Keep 'em ON the X! RG

Thanks Randy. That's a big wrap coming from you. I thought I would give it a shot as the guy seemed keen to learn but the questions were quite hard to give definative answers.

 

[TnTom]

Ok i see what your asking"
Like i have said before a picture is worth a thousand words.
The difference your seeing is length of the bullet.
The shorter bullets will have less bearing surface.
Actually for mass produced bullets thats pretty good.
If you change your oal to fit the proper seating depth in your rifle
you should get good group with the other bullets.
The best thing to do is select and sort them , then change seating to accomidate this. We use shims on our straight line seating dies that allow us to change seating depth at will.
If you seated all of them long into the rifling like some do.
The problem is solved That also raises pressures.
If you do want to use on specific depth like a lot of us do.
Then buy hand swaged bullets . Theres a big differance.
The hand swaged bullets are made much slower and are more uniform then most factory bullets.
Barts , Robbinett Euber are a few of the brands.
I think you will find that a good lot of Bergers will also fit your needs.
contact Eric Stecker and ask Maybe a certain lot is running really close.

Its not the length of the bullet that I'm measuring. The bushing in the photo which is included in the measurement simulates the diameter where the rifling begins in the chamber.

The measurement reflects the distance from the rifling to the base of the bullet including the length of the boat tail, the leading end of the bullet isn't part of the mesurement.

The measurement I'm taking reflects the variation in the trailing end of the bullet, everything behind where the bullet contacts the rifling to the end of the bullet.

I visualize the trailing end of the bullet having little or no variation and the excessive jacket material manifests at the meplat end of the bullet. That can be eliminated by simply trimming the meplat.

I suppose the trailing excess can be eliminated by trimming the base? If the meplat variation is of concern why not the excess at the base of the bullet.

I'll make a call and let you know what I'm told. I've never shot flat base bullets and have never look for this condition in them maybe it has only to do with boattails ???

I can load with no variation in jump that's not the problem my concern is the excess variation following behind the fired bullet.

Again thanks

 

[J. Valentine]

Im trying to identify the cause and effect of this .018" variation in base to ogive. Disregard any error in measurement, there isn't any.

The bullet is located in the bushing at a point .214 diameter.

100 bullets varied from 1.040" to 1.058"

group (1) 3 @ 1.040
group (2) 5 @ 1.042
group (3) 13 @ 1.044
group (4) 36 @ 1.046
group (5) 28 @ 1.049
group (6) 12 @ 1.051
group (7) 3 @ 1.058

What causes this condition in the manufacturing process.
what effect does it have on the path of the bullet.

Is it an indication that the bullets aren't of a quality level that is being implied as a "Competition" level.

When I load and shoot bullets from one group for ex. group 6 (all within .0005" of 1.051) my 5 shot group is good, .330

Repeating the process with bullets from group 2 again the 5 shot group is good .400".

There is a variation in the group center or point of impact by .500".

I've noticed this with lots from both Seirra and Nosler. Does this condition exist all all swagged bullets. I would think that "custom" would not.

I'd like to be able to use bullets from a lot that is more like within .002" - .003" maximum variation ogive to base.

Any recommendation?

thanks Tom

These small variations could be a combination of things some I have already expalined. Others are , you vernier may not be capable of repeated accuracy to the level you are trying to get. If you handle the bullets with your fingers heat from your hands can effect the size inconsistanly. If you measure on different temp days you will get inconsistancy.
The way you are measuring them gives no guarantee the each jacket is exactly square and straigh in the calipers jaws.
It will have no effect on the ballistic performance what so ever.
The engraving from the rifling in the bore will have a far greater effect on the physical surface of the bullet from a BC point of view. .001 difference in length will be irelevant .
From a bullet seating point of view it is the ogive to lands measurement that is important not the total length of bullet.
Custom made bullets are going to be closer in tolerance that mass produced bullets . Mass produced may be coming off several different transfer presses and end up in the same batch. That's the only way they can keep the price down.
I think for mass produced bullets they are very good.
My recommendations are stop obsessing about a .002 variation which in reality is more likely .0005 -.001 and shoot the bullets spend your time learning to read the wind .
You can't change the bullets you have only weigh and seperate them and start shooting.

 

[TnTom]

These small variations could be a combination of things some I have already expalined. Others are , you vernier may not be capable of repeated accuracy to the level you are trying to get. If you handle the bullets with your fingers heat from your hands can effect the size inconsistanly. If you measure on different temp days you will get inconsistancy.
The way you are measuring them gives no guarantee the each jacket is exactly square and straigh in the calipers jaws.
It will have no effect on the ballistic performance what so ever.
The engraving from the rifling in the bore will have a far greater effect on the physical surface of the bullet from a BC point of view. .001 difference in length will be irelevant .
From a bullet seating point of view it is the ogive to lands measurement that is important not the total length of bullet.
Custom made bullets are going to be closer in tolerance that mass produced bullets . Mass produced may be coming off several different transfer presses and end up in the same batch. That's the only way they can keep the price down.
I think for mass produced bullets they are very good.
My recommendations are stop obsessing about a .002 variation which in reality is more likely .0005 -.001 and shoot the bullets spend your time learning to read the wind .
You can't change the bullets you have only weigh and seperate them and start shooting.

So there is no misunderstanding I'm not talking about .001 or .002. The variation is .018" with no error in measurement. The bullets are seated square in the jig and the measured results are confirmed using an alternate method. a (.0005" indicator and stand) and again with a 1-2" starrett micrometer. The shop is controlled at 68 degrees. I've been involved in manufacturing for over 40 years and measure accurately. I understand about the problems involved in cost and why multiple cavity dies are necessary etc.

A venier doesn't have an indicator and can easily be misread is used by someone with limited measuring experience. Generally a someone who would call a dial caliper a venier.

All the bullets weigh within .1gr

 

[Gerry]

your mesuring the base of the ogive to the base of the bullet correct?
If so your measuring the length of the bullet ,
It can be solved the way i prooposed by either changing the seating depth with lots or seating them way out and into the rifling. at a set distance some will jump others will seat harder. If you set the seating just touching with the short length, the other will be into the rifling.
if you set the seating to the longer bullets to just touch the shorter bullet will be jumping .

 

[Steve Nash]

Tom,

If they are factory projectiles they were probably made on more then 1 machine and dumped in a bin before packaging. I found this with some Speers last year. I bought 1,000 and check the ogive on the lot of them and found 3 distinct lengths. They may also be seconds. Sierras seconds mainly vary in ogive length where as the Noslers had more of a crimp in the jacket or were over pointed. I also bought 500 Noslers that were supposed to be the good ones not seconds and they were the no better then the seconds.

Cheers
Steve

 

[Gerry]

Steve that may be honestly i don't know
you could ask speer about it.
It's possable they have more then one machine running to make a particular caliber.
It also may be adjustments made to the machine during manufacturing.
The machines are checked from time to time,
It could be quality control. I think you will find Burgers way better.
The prices here are pretty close.

 

[TnTom]

your mesuring the base of the ogive to the base of the bullet correct?
If so your measuring the length of the bullet ,
It can be solved the way i prooposed by either changing the seating depth with lots or seating them way out and into the rifling. at a set distance some will jump others will seat harder. If you set the seating just touching with the short length, the other will be into the rifling.
if you set the seating to the longer bullets to just touch the shorter bullet will be jumping .

Gerry I understand what your saying.

But Im not measuring the length of the bullet or the length of the ogive.

The distance being measured begins at a point on the bullet that comes in contact with the rifling and ends at the boattail end or base of the bullet Simply everything except the ogive length.

Lets discribe it as the length of the bearing diameter and the length of the boattail excluding the length of the ogive.

If I included the length of the ogive, the length of the bearing dia. and the length of the boattail then it could be described as the length of the bullet.

The sum of the boattail length including the length of the bearing diameter is varying about .018". The same sample displayed less than .003" variation at the meplat.

I'm aware of how to deal with the meplat end of the bullet - trim it or forget it.

I'm simply curious about the process more than anything else. Im going to give Sierra a call and ask them how they deal with it in the manufacturing process.

I'm familiar with a meplat trimmer but I don't think there is such a thing as base trimmer. I wonder why. Too simple I guess. Changes in the length on the tail end of the bullet has less impact on flight than changes in the length on the front end of the bullet?

 

[caroby]

Tom,

Measure other brands of bullets of this caliber... Customs too...

See how they all compare...

cale

 

[Fla mac]

TnTom,
I took a box of Cheeks bullets and checked them, with the calibers I used you could not see any difference between in his bullets (good bullets and shoots good in my gun). I also checked some of my bullets and they were from .000”
To .003”. What I do after I made my bullets is I measure each bullet and put them in lots by length +/- .002”.
john