Measuring bullet jackets?

R

rossi

Guest
Hello,
I am new to bullet swaging and have some questions that did not find any answer in other posts in the forum. Maybe someone might help me.

First question is about jacket wall thickness.
J4 and other producers claim jacket wall thickness with .0003 or less variation, but how can I measure this?
If I spin the jacket I am only measuring the outside of the jackets and see if it they are round or not. Should I define a reference height and measure different points (thickness) of the jacket?

Second is about point forming.
I have read that some fine lines on the ogive is normal and depends on the amount of lube used. I swage 308. with a 7,5s made by Niemi and noticed that I have these lines more on one side of the ogive, and not uniformly all around the bullet. Additionally I often see one line that looks more like some sort of fold or superficial crack than a “lube line”. I noticed this fine line on the samples I received with the die set too, but on the jackets I am using (J4) it looks somehow deeper. Are these lines normal?
I tumble lube with a rotary tumbler.
 
In case they miss your questions here, I recommend you give Ronnie Cheek and Bart Sauter a call. They've both been making winning bullets for some time and will have the answers you seek.

Ronnie can be reached here:
Ronnie Cheek
5002 Meadow Drive
Abilene TX 79606
(325)698-1318

Bart here:
Telephone
270-879-4279
Postal address
821 Phelps Johnson Road
Leitchfield Kentucky 42754
Electronic mail
General Information: the6PPC@aol.com
 
You need a ball mic with a stop on the anvil to measure thickness at the same depth all around the jacket.

Those "creases" can be diminished by reducing the lube. It's a balancing act trying to get rid of the creases and still have enough lube for the die to work properly. Incidentally, those creases don't hurt much.

The differing creases around the finished bullet indicate that the jackets are not uniformly lubricated or there is something screwy going on - like sweaty fingers.
 
It's a balancing act trying to get rid of the creases and still have enough lube for the die to work properly. Incidentally, those creases don't hurt much.
Click to expand...

Carbide dies "allow" one to minimize the swaging lube... But a set of Steel dies do need a bit more generous amount of lube, least you get a stuck jacket in the core seat or point-up die.... Also the more generous lube to Steel dies again IMOP help "slow" the die wear... Well a little anyway..

Those crease, IMOP Wilbur don't hurt at all except for "appearance"...
 
Wilbur said:
You need a ball mic with a stop on the anvil to measure thickness at the same depth all around the jacket.

Those "creases" can be diminished by reducing the lube. It's a balancing act trying to get rid of the creases and still have enough lube for the die to work properly. Incidentally, those creases don't hurt much.

The differing creases around the finished bullet indicate that the jackets are not uniformly lubricated or there is something screwy going on - like sweaty fingers.
Click to expand...

Sweaty fingers, yes that might be something to consider.
I must admit that am still not too clean on my workbench... My very first lot shot wonderful, BR quality, then I wanted to test different weight settings, see what happens with a different meplat size, and since then quality is not the same anymore. Unfortunately I did not keep any records of my first lot. I wondered how easy it was to achieve excellent bullets…well, I must admit that I have only been lucky with my first attempt.
The last 100 bullets I swaged are better than the 100 before. If I sort my own bullets I have good results, but the fact that I have to sort them, means to me that I am still not working properly.

I’ll invest in a good mic and will stop playing with the jackets before I swage them :)
 
Currently I weight the lube on a piece of plastic foil, smear the lube inside a jar like this

http://img545.imageshack.us/img545/9339/vasiconserve3vgdv.jpg

fill it ¾ with jackets and tumble in a thummler’s tumbler for about 30 minutes. I began using this method a few days ago, before I tumbled the jar by hand for about 5 minutes, using more lube. Tumbling for longer time I have the feeling I can use less lube and get a better lubrication.
 
rossi said:
Hello,
I am new to bullet swaging and have some questions that did not find any answer in other posts in the forum. Maybe someone might help me.

First question is about jacket wall thickness.
J4 and other producers claim jacket wall thickness with .0003 or less variation, but how can I measure this?
If I spin the jacket I am only measuring the outside of the jackets and see if it they are round or not. Should I define a reference height and measure different points (thickness) of the jacket?

Second is about point forming.
I have read that some fine lines on the ogive is normal and depends on the amount of lube used. I swage 308. with a 7,5s made by Niemi and noticed that I have these lines more on one side of the ogive, and not uniformly all around the bullet. Additionally I often see one line that looks more like some sort of fold or superficial crack than a “lube line”. I noticed this fine line on the samples I received with the die set too, but on the jackets I am using (J4) it looks somehow deeper. Are these lines normal?
I tumble lube with a rotary tumbler.
Click to expand...

Niemi dies are carbide, necessitating only very LITTLE lube: depending upon specific jacket LOT demands, for [1500] thirty caliber, 1.00" long jackets, I use as little as 2.0 GR. Lube at least 1 and one-half buckets ( depending upon jacket length, +/- 1500 jackets) at a time: as opposed to smaller quantities - especially 100//200 at a time - assuming that you're using a reloading balance, which 'measures' 0.1 Gr. increments, this will reduce any weighing error dramatically: ie., a 0.1, or, 0.05 Gr. error on 2.0 Gr. is a much smaller %age than the same error at 0.2 Gr.!:eek:

Using the appropriate tools, measure EVERY attribute; RECORD every attribute (diameter/length/etc.) - be prepared to adjust lube/set-up accordingly - the jackets will dictate what to do - the RECORD KEEPING will, eventually, provide a usable road-map . . . LUBRICANT is a necessary EVIL! :eek:;) Keep EVERYTHING CLEAN! Oh, and keep RECORDS . . . ;) The most likely culprit, for your 'wreck', was core-seating . . . difficult to trouble-shoot from afar . . . :eek:RG
 
rossi

Tumbling for 30 minutes seems to be more than is needed to get a uniform lube coating on the jackets. I use a method for lubing 6mm, J-4 jackets that seems to work well for me in my carbite dies. I use a Tumbler's Tumbler Model B which is a large tumbler. I put the jackets, approximately 300, in a 34 oz. Folger's plastic coffee can which is a perfect fit for this tumbler. The Folger's can has two recesses in it that is part of the built in handle. These recesses provide a vane to help tumble the jackets instead of having them just slide around which can happen in a round container. I first coat the inside of the can with lube on my fingers, add the jackets and heat with a hair dryer for about 30 seconds. I then tumble for 5 minutes. The result is a uniform coating of lube on all the jackets.
 
I don't see how jackets can be tumbled too long but othere may have a different view. Wipe the lube toward the bottom of the jar and set the tumbler such that the jar is mouth up at about a 45 degree slant. Turn it on and go to a movie.

If the jar is not kinda clear you either need to tumble more or cut back on the lube.

Was serious about those sweaty fingers. If you can't fix it otherwise, cut the fingers out of a latex glove and stretch 'em on the fingers you use to handle pieces as you swage. Now and then, wipe the latex on your pants to prevent lube build up.
 
I reduced the amount of lube and the signs diminished. This worked, thanks.
I think I really have an issue with core seating. I have a boat tail seater, and the punch of my point form die is obviously shaped like the base of the bullet. The seating operation forms the boat tail, but I noticed that in the point forming operation the boat tail is reshaped again by the geometry of the PF punch. Is this normal? I tried to seat the cores harder, screwing down the seater die, and the jackets did expanded beyond the diameter they have when coming out of the PF die so, in fact, I think I did swage the bullets down to final diameter and not up. On the other side, if I do not seat the cores hard, I have the feeling that the base does not form completely and is reshaped by the outer punch of the PF die more than if I seat cores hard.
I think there must be a good middle in between, but do not know how much pressure is needed and what diameter I should aim to. Additionally, I often read that flat base bullets have a pressure ring but didn’t find anything about boat tail bullets. I measure the diameter at the beginning of the BT, this is where the bullet has its maximum diameter, but shouldn’t the bearing surface have exactly the same diameter too? Maybe the seating punch is too small and I should increase its diameter? During core seating, should I set the die to achieve exactly the same diameter as in the PF operation or slightly smaller?
 
Rossi,

Seat the bullets as hard as you can until you start to see a frosty ring around the lead line. Then back off but only enough to stop the frosty lead line. Don't worry about the diameter. The bullet should fully form to whatever the die allows. The important thing in the seating operation is that you seat them as hard as you possibly can. Also, make sure you have a small amount of lead flash that goes around the punch or you might be trapping air which is bad.

The pointer punch on BT bullets will always give you the final shape of the BT. There is no way to avoid this and as long as the punches are good this isn't a problem. BT bullets typically have a pressure ring but if they don't it is not the end of the world. It just means that your die doesn't have much or any taper (which is unusual but not necessarily bad). Do all this and shoot some of your bullets. Your rifle will tell you if you got it right (assuming it is working too). :)

Regards,
Eric
 
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Eric Stecker said:
Rossi,

Seat the bullets as hard as you can until you start to see a frosty ring around the lead line. Then back off but only enough to stop the frosty lead line. Don't worry about the diameter. The bullet should fully form to whatever the die allows. The important thing in the seating operation is that you seat them as hard as you possibly can. Also, make sure you have a small amount of lead flash that goes around the punch or you might be trapping air which is bad.

The pointer punch on BT bullets will always give you the final shape of the BT. There is no way to avoid this and as long as the punches are good this isn't a problem. BT bullets typically have a pressure ring but if they don't it is not the end of the world. It just means that your die doesn't have much or any taper (which is unusual but not necessarily bad). Do all this and shoot some of your bullets. Your rifle will tell you if you got it right (assuming it is working too). :)

Regards,
Eric
Click to expand...

Eric,
I followed your suggestions and can clearly see that the BT is formed much better than the bullet before. With the current setting, if I screw the seater die further down the bullet does not expand anymore but a thin ring of lead shows on the inner walls of the jacket. If I look at the jacket from the outside I see a ring at the lead line. Am I stressing the jacket too much and should I back off the die a little further?

Besides, what really puzzles me is that I received a few swaged cores, seated cores and finished bullets made by Niemi before he sent me the die set. The jackets of the seating operation are all expanded to .30811 and the base of the BT is wide and flat. If I try to seat a core to that outer diameter my bases have wide round edges and are far from being flat. The more I increase pressure, the more the BT fills out and becomes like the samples Niemi sent me, but the diameter of my seated components is .30850 - .30855 and that is far away from the sample’s dimensions. I use pure lead and J4 jackets so the material should be the same as used by the diemaker, but have never been able to replicate the dimensions of the samples.
The only adjustment possible on Niemi’s core seating die is the depth of the die in the press, the ejection stem is fixed. I am really asking myself if I am doing something completely wrong or if the samples did not come out of the die I received.
 
A lot of bullet makers adjust their seating die as Eric described - myself included. There is, however, a built in deal that takes care of the adjustment for practical purposes. If insufficient pressure, the bullet will stick on the punch. If too much pressure, the jacket will rupture. If every bullet comes off the punch and none rupture the you're "between the ditches" and likely good to go.

Don't know why the differences in your bullets and the samples but I'll guess that there's a difference in the components used. Four tenths is not exactly "far away" and if the measurement is taken at the base the dimension may be forming on ejection. Concerning a flat base bullet, the "pressure ring" forms on ejection. Otherwise, it couldn't be ejected......
 
rossi said:
Am I stressing the jacket too much and should I back off the die a little further? Besides, what really puzzles me is that I received a few swaged cores, seated cores and finished bullets. The jackets of the seating operation are all expanded to .30811. If I try to seat a core to that outer diameter my bases have wide round edges and are far from being flat. The more I increase pressure, the more the BT fills out and becomes like the samples Niemi sent me, but the diameter of my seated components is .30850 - .30855 and that is far away from the sample’s dimensions. I use pure lead and J4 jackets so the material should be the same as used by the diemaker, but have never been able to replicate the dimensions of the samples. The only adjustment possible on Niemi’s core seating die is the depth of the die in the press, the ejection stem is fixed. I am really asking myself if I am doing something completely wrong or if the samples did not come out of the die I received.
Click to expand...

We are getting into some more advanced issues related to bullet making. First, let me start by saying that everything I relay is my opinion based on things that have worked for us. Other bullet makers can have success using other methods so keep this in mind. In our shop, the only time you've stressed a jacket too much is if the unsupported portion of the jacket pops off the seated bullet at the lead line. You have probably broken a jacket in this manner. This is too much pressure. Any amount of pressure that doesn't result in the jacket separating into two pieces is not too much.

To be clear, many shooters don't like the white (what we call "frosty") ring around the lead line. They can't explain why but they don't like it. This frosty line is different than a line that appears when you are seating the jacket hard. You should always have a clear line that shows you precisely where the end of the core is and this line needs to look the same all the way around the bullet or you have a worse problem. If you start seeing a second "frosty line" then you are getting close to the point where the bullet will break apart (too much pressure).

Regarding matching your bullets to the samples. In my opinion this is a waste of time. We work to make all our bullets precisely the same as the last run (dimensionally) but for reasons we can't fully explain this is almost impossible to accomplish lot after lot. It is our opinion that this has something to do with different lots of materials and the tooling used in the jacket and core run. We believe that nearly undetectable factors within the material and how it is formed produces a difference in how they form into a bullet. The bullets won't vary from within a lot but to vary from lot to lot is normal.

In your case you are finding .0004 larger diameter than the samples. If everything is done properly, this is not uncommon. A few things you can check if your are interested is to measure the bullet 24 hours after you form it. It is possible that the bullet will shrink some amount (this doesn't happen to every lot but it can happen). Another thing you can check is the cleanliness of your cores. The slightest amount of lube on the cores can act as a hydraulic and affect OD. You will also want to make sure your jackets are clean on the inside. The way we do this is to rub a cotton swab inside the jacket. If it is dirty you will see very definite black material on your cotton swab.

Another thing to consider is that the Niemi's have been making dies for a long time. It might pay for you to contact him with your results and get his thoughts. I'm sure this is not the first time he's seen this type of thing and can speak more intelligently on how his die might affect this result.

Regards,
Eric
 
I thought everybody washed their jackets is some kind of super duper quick drying solvent. Call Mr. Niemi if you like but Eric is a definitive source. Eric also knows a guy...and that guy knows a guy...etc..
 
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