Bullet core stripping

I thought I'd wait for a handful of posts to be added before I made one, just to see how much would be shared. I came in this afternoon and found that there were a whole lot of new ones....clearly an interesting topic to many. I had help getting started in 2000 from a number of excellent and helpful bullet makers. There are a few noteworthy things that I haven't seen mentioned yet. First, it seems like there hasn't been much mention of jacket washing. The jackets do have a film inside that I believe has to be removed before they are lubed. I swish them in a container of highly volatile stuff and dry them on paper towel-lined trays.....outdoors.

Also, there has been lots of mention of cleaning and etching cores. I believe that it is important to use a lubricant for forming that is easy to remove. There was mention in one of the earlier posts of a silicone lube(!)........Silicone is nearly impossible to remove completely...Just ask any painter; it gives them fits if previously used on a substrate they end up trying to paint. I use a water-soluable oil, rinse as much as possible off after forming, and then heat to a lazy boil in dishwasher detergent & water. I flood the water out of the pan with a slow trickle instead of pouring it off, because the oil will be floating on top......pour it off and the oil will be re-deposited on the cores. I then spread the cores out on a towel (which of course dampens the towel) and cover them with another damp towel. I peek at them once in a while, and when the grey color is just right I remove the top towel and let them dry.

Finally, like others mentioned, I believe core seating is the single most important detail. I too got Skip Otto's crash course on core seating. In short, I look for the shortest possible jacket length after core seating, which indicates that the jackets are being filled out completely, while not being pushed to the point where jacket material is being displaced. I write down the "short length" and spot check regularly while seating to verify that nothing has changed.

Oh, I almost forgot......like others have said, I wait at least a day before pointing up. Skip told me that the etched cores and the jacket material react to one another and more or less become bonded by the resulting "stuff" (corrosion?). He said that one could measure the increase in bullet diameter caused by the "stuff"........sure enough, there is a perceiveable increase in diameter a day after seating.

It'll be interesting to see how much more info is shared as this thread progresses.

-Dave-:)
 
To clarify:

Al

Improper smelting practices can result in dross in the finished product. Improper extrusion practices can result in lamination and air in the finished product. Also if you add antimony there are numerous places in the process that you may end up with unwanted heat treating and a less than perfect homogenous makeup.

Ken
 
J valentine

My mistake is clear, I stand corrected.
I meant to say that all 99% lead, certified.
just may not be that wonderful. I sold
all of the remaining lead to the fisherman.
Ken Hope is very knowledgeable about lead, I
will use 99% lead from good scources only.
I don't believe that we have a problem with stripping cores.
It does defy the laws of motion, IMO No bullets were made using that
wire. I also cant believe that no one else has run into this before.
If poor manufacturing processes don't go hand in hand with Quality
control, what does
 
K Hope,

Thank you.

My total experience with lead only includes casting bullets and sinkers. I've "felt" that having a cold breeze blowing (casting bullets outside for fumes) could result in bullets of uneven hardness but that's ll I know. (think :rolleyes: )

i just wasn't sure what you meant.

al
 
Great progress!

Thanks to all who took the time to share with us their knowledge and experience in making match grade bullets. Judging by the number of views, there is great interest in this subject. Let's keep it going. :D

We received some great feedback on making and seating bullet cores, now let's move on to what many believe is the single most important ingredient in the bullet making process,, JACKETS!

Mike Ratigan, the present and two time World Benchrest Champion, devotes an entire chapter in his recently published book, "Extreme Rifle Accuracy" to the subject of what he calls, Superman Bullets. Mike begins this chapter by saying,

"Bullets! Bullets! Bullets! Bullets are everything to the competitive Benchrest Shooter."

Now, that's a pretty profound statement; huh? But Mike is absolutely right; nothing will overcome bad bullets.

Mike goes on to say, "Larry Engelbrecht and I have spent many hours talking about the phenomenon of Superman Bullets. Larry, (now deceased) retired as a troubleshooter for the CEO of Cessna Aircraft after more than fifty years. Larry is a past regional director of the NBRSA Mid-Continent region, NBRSA President 80 & 81 and custom bullet maker for over 40 years. He has been shooting Competitive Benchrest since 1956. Only Mike Walker, Walt Berger and George Kelbly Sr., have more experience."

Wow! That's a lot of experience; isn't it? I'm glad I got to meet and shoot with Larry before he passed away. He was and always will be, a legend. :)

Mike Ratigan believes, as do many other experts, that the quality of the jackets determines the final accuracy potential of the bullet. In chapter 7 of his book, he says, "The bullet dies alone are not a factor in the accuracy potential of the final product other than they must be concentric and straight. Who knows what property of the jacket is responsible for the exceptional performance of the Super Man bullets? One thing we do know is that whatever it is, it's not something you can measure with simple inch measuring tools."

Mike Walker, formerly of Remington, stated, "In his experience the quality of the gilding metal from which the jackets were made was responsible."

So,, there you have it; the most experienced and successful shooters and bullet makers in the world agree; in order to make Super Man Bullets one must begin with Super Man jackets.


Gene Beggs
 
This is the hard question for sure , because for most swagers the jacket is the part they have least control over how it is made.
It is fairly accepted that jacket concentricity is a major factor in making an accurate bullet.
If the jacket is out of ballance then no matter how good the cores are or how well you do all the other things the imbalance remains and will show up on the target.

Got to go back later
 
J. Valentine said:
This is the hard question for sure , because for most swagers the jacket is the part they have least control over how it is made.
It is fairly accepted that jacket concentricity is a major factor in making an accurate bullet.
If the jacket is out of ballance then no matter how good the cores are or how well you do all the other things the imbalance remains and will show up on the target.

Got to go back later
Click to expand...


J., have you ever experimented with annealing jackets?
 
Gene Beggs said:
J., have you ever experimented with annealing jackets?
Click to expand...

Yes I have experimented with annealing jackets , re drawing jackets to improve concentricity , lathe triming jackets to improve meplats and drawing down jackets to smaller calibers.
Annealing a jacket takes the spring out of the metal . This can be good for making a bullet tougher for hunting game but a soft jacket will not grip the bullet as well after the point forming pressure is removed , because there is less spring back .
Also it can increases copper fouling to some degree.
There is a fine balance of ductility between good spring back and a jacket that is soft enough that it forms well and will not fracture in any way in the rifling and cause a blow up.
What this best ductility is I can't quantify.
However I found that after annealing , one or two draws through reduction dies produced a workable jacket that had some spring back but was ductile enough to swage normally and not pop the jacket at the ogive. They did shoot as good on average as my other commercial jackets.
So I decided that annealing had to happen every second drawing.
I have never made jackets from scratch only worked on existing jackets.
However if I did make them from scratch , I feel , and proffesionals correct me if I'm wrong.
That I would have to:--
Blank the gilding disc.
Cup the disk.
Anneal.
first draw .
second draw ( more steps may be required )
anneal
final draw
and trim to length.
The final anneal with only one last draw should leave a gilding metal 95% copper 5% zinc jacket at a good workable hardness.
The core seating and point form will also add some work hardening.
Proffesional jacket makers would have more scientific ways of testing hardness and adjusting their process.
However I have seen poped jackets on bullets from major brand names.
I think we are all at the mercy of the jacket maker.
My annealing methods were very basic.
I tried imersion in hot lead which is how I do my case necks.
Also heating with an electric heat gun which is how I do my corebonded bullets.
Both worked but how well is another issue.
I settled on the heat gun as It is quick and handy and I could tell from the change in drawing pressure required that it was annealing.
However I feel that to get perfect concentricity on a draw or re-drawn jacket , more precise annealing methods are required so that jacket ductility is even all over the surface to be drawn.
That is beyond my present capabillities and budget .
So to recap I dont think there is a lot to be gained in paper punching by shooting a dead soft jacket or a dead hard jacket some place in the middle is good . I wish I had some Brinell hardness figure to quote but I dont.

I think some bullet blowups can be a result of over hard jackets that are right on the edge of spliting at point forming then fracture as the rifling engraves the bullet and the ogive pops in flight and poof.
 
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Stephen Perry said:
Joe
I woke up from a deep sleep and read your comment on double pumping cores. I have been doing this for 10 years now at my mentors recommendation. Takes a small amount of extra time but the second pump blows off the tailings and gives a core that is plus or minus a tenth for as long as you want to pull the handle. Good catch Joe I know more than I can remember. You don't forget. Have to go back to watching HOUSE, he is also my mentor like Stiller is when he comes on.

Stephen Perry
Angeles BR
Click to expand...

Yes mate I'm a bit of a double pumper too.
The second swage seems to get a more compressed core with much finer surface texture. So I am assuming that the internal texture may be denser also. You cant section a lead core and not disturb the surface texture. Anyway it does produce a tighter weight tolerance and that must be better.
 
Joe, thanks for the great response to my question, "Have you experimented with annealing jackets."

Most interesting indeed! Good point about a dead soft jacket being easy to form but since the springback is greatly reduced as a result, the jacket does not get a good grip on the core. :eek:

You and many other well informed and experienced individuals remain skeptical about core stripping and if someone other than Harold Vaughn had suggested it to me, I'm sure I would have been skeptical also. But after studying his book and correlating that information with what I have experienced during the past several years, I am convinced; core stripping can and does occur. Vaughn's tests remove all doubt.

In closing, I would ask you to consider the following;

"If core stripping is not a problem as you and many others believe; isn't it interesting that so much of what goes into making custom bullets pertains to the bond between jacket and core?"

Later,

Gene Beggs
 
Annealing jackets was a standard in the use of tube bullets jackets. I believe that a little annealing is better than a complete anneal. I have read that the problem with to much annealing is the jacket will collapse in the point forming die. There is a lot of information about this is in Corbin's books. Of course this was in jackets made from copper water pipe. Ridged, not soft copper tubing. The reasons in part was that tube jackets would fail is due to the roll stamps on the ridged tubing. The stamps had to be filed out or the jackets would fracture on impact and had to be annealed.

As to bonding the cores, this has been successfully accomplished with flux and heat. I know of one bullet manufacture that makes his own (drawn) jackets and bonds the cores and his bullets are the most amazing I've shot for a thick jacketed (0.035") bonded core bullet. I'm not claiming bench rest accuracy with these bullets as they are made for hunting purposes only.


As to the statement about being about," being at the mercy of the jacket maker", I'm not sure if this has to be the most truthful statement I've ever read on the inter-net, BUT IT HAS TO BE CLOSE! Go look at the gyrations the Old Timers use to go through to get the jackets right, George Kelbly can show you the equipment they used.
 
Gene.....

Never said core stripping was not important to discuss. I said that with custom hand swaged Benchrest Bullets from any of our fine supplyers, it is a non-issue.......jackie
 
Gene Beggs said:
Joe, thanks for the great response to my question, "Have you experimented with annealing jackets."

Most interesting indeed! Good point about a dead soft jacket being easy to form but since the springback is greatly reduced as a result, the jacket does not get a good grip on the core. :eek:

You and many other well informed and experienced individuals remain skeptical about core stripping and if someone other than Harold Vaughn had suggested it to me, I'm sure I would have been skeptical also. But after studying his book and correlating that information with what I have experienced during the past several years, I am convinced; core stripping can and does occur. Vaughn's tests remove all doubt.

In closing, I would ask you to consider the following;

"If core stripping is not a problem as you and many others believe; isn't it interesting that so much of what goes into making custom bullets pertains to the bond between jacket and core?"

Later,

Gene Beggs
Click to expand...

You are welcome Gene, I never said it can't happen. I said I can't see the problem in todays bullets in the present swaging situation.
Read back my description of the mass production scenario with bullets made under poor conditions and cores swaged in one punch stroke into dusty and dirty jackets . I was saying that I can see the possibility for loose cores in badly made bullets . However I can't see any evidense that it is a problem in well made custom bullets .
A lot has changed in 30 years in the quality and precision of all BR equipment and bullets in general .
I have no doubt that Harold Vauhan witnessed and recorded bullets having accuracy problems or blowups , how he would be able to prove it was a core stripping problem I would be interested to hear.
Just like I have witnessed faulty jackets and poped jackets and blowups from a certain major bullet manufactures product . Not many but a few boxs now and then.
However I have never had a single problem with my own bullets as far as a blowup of any kind or a faulty jacket because any bullet with an obvious external fault or one that just does not swage or feel right is a reject.

I mean I could have done tests on those faulty Berbers and then pronounced to the world that they are all no good and the bullets blow up and the cores stripped.
That would be just pure rubbish because a few faulty bullets in millions is just bad luck not proof of a systemic problem within the design or manufacture of the other 10 million good bullets .
Mr Vahaun may have just got hold of some realy crook made bullets that did exibit failures for what ever reason and he went about trying to explain why they failed.
He may well have been right for that batch of crook bullets but that does not mean that all bullets have the same problems .
I mean if core stripping is a big issue then how does anybody shoot a winning BR group with any bullet?
 
Gene Beggs said:
You and many other well informed and experienced individuals remain skeptical about core stripping and if someone other than Harold Vaughn had suggested it to me, I'm sure I would have been skeptical also. But after studying his book and correlating that information with what I have experienced during the past several years, I am convinced; core stripping can and does occur. Vaughn's tests remove all doubt.


Gene Beggs
Click to expand...

Gene,

You may have missed these core slippage statements by Vaughn;

-pg 156..."Now before anyone gets excited I want to point out that 6mm 68gr match bullets perform very well in benchrest rifles with a 14 inch twist, where they are intended to be used."

-pg 159..."The 68 grain 6mm bullets should survive a 14 inch twist and the experimental data shows that it does."

Vaughn clearly felt that there was no core slippage problem with standard competition BR style setups. Core slippage did not seem to be a factor until spin rates got into the 6mm, 1 to 10 twist rate region and very high pressures/velocities.......Don
 
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I'll bring you back once again to my 6x47 Lapua with a 1 in 10 twist barrel. It shoots my 68 grain bullets at 3,700 fps into groups that most ppc's would be happy with... In this case, core slippage is a non issue.. These bullets are made using conventional techniques, nothing more.
 
Stephen, you are a life long BR shooter and bullet maker, have you encountered core stripping issues? Another question, how many ppc barrels have you seen that will reliably shoot under .250 at 200? Every time ??

I already said in my post my bullets are made like everyone elses, nothing different..

The 6x47 often shoots in the .1's at 100, not 200.. I haven't even grouped the rifle at 200 as it doesn't matter.. It's not a benchrest rifle and will never see a match.. It is, however, an extremely accurate varminter that shoots these 68's well in a faster twist barrel, nothing more.
 
All the techniques I use to make bullets have been mentioned here by none other than YOU, Stephen.. My comments were made to convey that in the instance of my faster twist rifle and conventional BR bullets I have seen no evidence that would lead me to believe that core slippage was occuring.
With that, I will wish you a Merry Christmas and a happy new year. Thank you for sharing your knowledge on this forum.
 
J. Valentine said:
You are welcome Gene, I never said it can't happen. I said I can't see the problem in todays bullets in the present swaging situation.
Read back my description of the mass production scenario with bullets made under poor conditions and cores swaged in one punch stroke into dusty and dirty jackets . I was saying that I can see the possibility for loose cores in badly made bullets . However I can't see any evidense that it is a problem in well made custom bullets .
A lot has changed in 30 years in the quality and precision of all BR equipment and bullets in general .
I have no doubt that Harold Vauhan witnessed and recorded bullets having accuracy problems or blowups , how he would be able to prove it was a core stripping problem I would be interested to hear.
Just like I have witnessed faulty jackets and poped jackets and blowups from a certain major bullet manufactures product . Not many but a few boxs now and then.
However I have never had a single problem with my own bullets as far as a blowup of any kind or a faulty jacket because any bullet with an obvious external fault or one that just does not swage or feel right is a reject.

I mean I could have done tests on those faulty Berbers and then pronounced to the world that they are all no good and the bullets blow up and the cores stripped.
That would be just pure rubbish because a few faulty bullets in millions is just bad luck not proof of a systemic problem within the design or manufacture of the other 10 million good bullets .
Mr Vahaun may have just got hold of some realy crook made bullets that did exibit failures for what ever reason and he went about trying to explain why they failed.
He may well have been right for that batch of crook bullets but that does not mean that all bullets have the same problems .
I mean if core stripping is a big issue then how does anybody shoot a winning BR group with any bullet?
Click to expand...


J, thanks for taking the time to respond with such a thorough and well written post. You are certainly correct in saying,

J. Valentine (quote) "A lot has changed in 30 years in the quality and precision of all BR equipment and bullets in general." (end quote)


Some may have erroneously concluded that I believe core stripping is a really big problem and occurs all the time. No,, not at all; I'm just saying that core stripping MAY be the reason some lots of bullets will not shoot when they appear to be perfect in every way, made in the same dies, with the same lot of jackets and other components. Maybe the only thing different was the fact that the cores were not properly degreased or perhaps the cores were seated too hard or not hard enough.

A top notch, very experienced shooter and bullet maker once told me his bullets just 'came alive' when he reduced core seating pressure. Could it be he was simply stretching the jackets excessively, which reduced the grip on the core? I suspect that was the case because nothing else was changed.

Thanks again for the good feedback. :)

Gene Beggs
 
Lead on bullet punch

Question - How do you keep lead from building up on punches during core seating, and how do you remove it if it does build up?
 
Gene Beggs said:
A top notch, very experienced shooter and bullet maker once told me his bullets just 'came alive' when he reduced core seating pressure. Could it be he was simply stretching the jackets excessively, which reduced the grip on the core? I suspect that was the case because nothing else was changed.
Click to expand...

Gene Beggs
Click to expand...

I believe any stretching of the jacket is excessive. The problem with stretching the jacket isn't so much that the grip on the core is lost, but instead that the jacket wall doesn't stretch evenly. When material is displaced and and flows, the bullet becomes inbalanced and is no longer straight. Also, the material that moves work hardens, so the material hardness isn't consistant throughout the jacket. I don't think the "core stripping" theory plays into the stretched jacket scenario.

Start with good jacket and dies, keep everything as consistant as possible, make sure the jacket interiors and cores are clean, seat the cores so that the jackets are filled out but not stretched, rest the bullets for a day, point carefully and cull out any odd-feeling ones, and you'll have as good a bullet as the dies will make.

-Dave-:)
 
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