Bullet core stripping

[Tim Singleton]

Thanks for the help

Not all were born with the bullet making knowledge as some have been
Those of us who weren't gotta ask questions

 

[alinwa]

Thanks for the help

Not all were born with the bullet making knowledge as some have been
Those of us who weren't gotta ask questions

Hey Tim....I see this differently.

Ain't nobody born smart, these guys worked hard and spent lots of money and now they share with guys like you and me...

I say THANK YOU for sharing your hard earned knowledge!!!

 

[Tim Singleton]

Hey Tim....I see this differently.

Ain't nobody born smart, these guys worked hard and spent lots of money and now they share with guys like you and me...

I say THANK YOU for sharing your hard earned knowledge!!!

My attempts at a little bit of humor usually doesn't go well.
I certainly appreciate everyone sharing their hard earned knowledge

 

[alinwa]

My attempts at a little bit of humor usually doesn't go well.
I certainly appreciate everyone sharing their hard earned knowledge

Awwww, now ya' made me feel bad.....

I wasn't trying to pick on ya's man!

I think we agree, THANK YOU to all these guys who share this stuff wit' us mortals....

 

[Ian_Owen]

You can't take a too large core and "press fit" it into a jacket with any success. The process is called "swaging up".......in other words, the core seating process EXPANDS the jacket, and the core seated jacket, ready to point form is smaller than the finished bullet. The final process of point forming expands the jacket a bit more to the final dimension.
Think of the jacket as that half empty toothpaste tube that has been squeezed in the middle, then you start rolling it up from the bottom........the rest of the tube expands (this assumes you have the cap on tight)
To give a little more insite, suppose you have a bullet that is 6mm and you want to make it a .22, like necking down a case. You could squeeze it down in the die, but the spring-back of the copper jacket would work in reverse and it would spring back towards it's original size and the core would quite possibly rattle in the jacket.
The only time a bullet component is reduced in size is when the core itself is squirted to a specific size. From there on out, everything expands.
Copice?
Bryan

A cure for an unproven problem?
It is a fact that greasy or dirty cores and jackets are not good for accuracy but many millions of good accurate bullets have been made with 99% pure lead cores and just a good solvent degrease , washing and drying of both , Some people age their cores until a slight white corrosion appears.

If core slippage is really a problem then why? oh why? do corebonded bullets not shoot better than unbonded bullets on average. (I actually know why.)
If I make identicle 308 projectiles one corebonded and the other unbonded the unbonded one shoots the best groups.
I am not trying to put down Gene's ideas . I am trying to understand where this alleged core slippage is causing a problem.
I dont belive that Mr Vaughn is correct about this rotational inertia causing core slippage as a bullet exits the muzzel because I believe that the whole mass of the bullet would be spinning as one mass by the time it exits the barrel. Providing the bullet is properly made . At the point where the bullet enters the rifling there COULD be some inertial stress on the jacket core junction . However I theorise that it would be all over and settled down by the time the bullet exits.
I think Mr Vaughn may have been grasping for answers to explain bullet blow up which can be caused by a whole set of other circumstances . Some of which do involve thin jackets and deep rifling , rough barrels , heating of the bullet etc.
Berger is working on it now.
It is theoretically possible for a poorly made bullet with a poorly seated core
fired under mild pressure circumstances in a generous size bore to have a loose core on exit from the muzzel . However it would not be accurate and may not even make it to the target .
Conversely a very tight bore can swage down a projectile and on exit the jacket springs out and loosens the core.

This is a very interesting thread, and after rereading it I have a question.

I read Bryan's post about sizing 6mm bullets to .22 and thought that makes sense, lead is a dead material and will not expand after being squeezed down. Then read Mr Valentines post and the last sentence made me wonder.

Ok starting with a new barrel and it aggs in the high .2's, then after a few rounds, say 1200 or so using the same lot of bullets the barrel seems to really start shooting with less bullets out of the groups and more shooting into the group when you think they should go out.

Could this change in the barrel be caused by a "better" match of inside barrel dimensions, after some barrel wear, to the size of the bullet being used??

Or could this change be caused by the load not being quite in tune when the barrel was new and as the barrel wears now being totally in tune??

To me the idea of squeezing a bullet into the bore of a barrel could induce core slip if the jacket, upon exit, can expand to such an extent that you lessen the grip on the core, perhaps this is why some bullets shoot better in some barrels than others.

Ian

 

[GerryM]

Bullet core striping

To say the least this thread seems to go around in a circle at time,s
If your talking about the core coming loose in the jacket I think that would be pretty rare
If there is lube on the core by not being clean it might happen under extreme conditions. Lead is a dead material and when it is seated it is expanded to the jackets very very tightly unless the bullet maker has
failed to adjust his seating die to expand to the proper OD before pointing.
Some of the biggest No No,s in bullet making are this CORES too big to go to the bottom of the jacket and entrapping air under the core.
Dirty cores that still have lube on them.
wrong punch allowing bleed back on the side walls and making the bullet off balance.
Improper core seating pressures ,or pressures that are uneven due to big variations in core weight,
When fired the bullet is expanded out into the rifling and the rifling engraves the jacket and the core making the lead tighter in the jacket by being swaged under high pressure and gas.
How can it actually strip???

 

[Wilbur]

I think that if the bullet comes out of the core seating die and doesn't stick on the punch, adequate pressure has been applied. Any greater pressure simply causes the jacket to stretch at the lead line...some believe this is a good thing and I won't/can't argue. I've done it both ways and couldn't find a difference.

 

[Wilbur]

Ian - those are certainly good questions. Nobody knows the answers but good questions nonetheless....

 

[geo.ulrich]

interesting thread at least its good for a few laughs, funny to read all the wives tales on bullet making as in Brians swage up theory I haven't made CARBIDE DIES and swaged up in years works good on steel not on carbide or to big a core will trap air. I have tried and tried with cores that just barely went into jacket and with correct punch you will not trap air do I use smaller cores sure do its easier to just place on punch and core seat, as for lead being a "DEAD" material there is no such material everything is in a constant state of movement so squirt a core and check in a day or two IT'S not the same size. Gerry pretty well has it right no oil or oxidizing of cores they are barrier layers between core and jacket. Did this one early on also take however many jackets and cores oiled ,oxidized and clean and dry core seat grab in collet drill a small hole in base then press them out on a scale you'll see which are really seated.....I guess that's enough of a visit for this year.....George over and out

 

[Gene Beggs]

Thanks George

interesting thread at least its good for a few laughs, funny to read all the wives tales on bullet making as in Brians swage up theory I haven't made CARBIDE DIES and swaged up in years works good on steel not on carbide or to big a core will trap air. I have tried and tried with cores that just barely went into jacket and with correct punch you will not trap air do I use smaller cores sure do its easier to just place on punch and core seat, as for lead being a "DEAD" material there is no such material everything is in a constant state of movement so squirt a core and check in a day or two IT'S not the same size. Gerry pretty well has it right no oil or oxidizing of cores they are barrier layers between core and jacket. Did this one early on also take however many jackets and cores oiled ,oxidized and clean and dry core seat grab in collet drill a small hole in base then press them out on a scale you'll see which are really seated.....I guess that's enough of a visit for this year.....George over and out

George, thanks for taking the time to share your priceless knowledge and experience with the rest of us. I look forward to your posts about bullet making so much.

Please understand that I do not consider myself an expert on benchrest bullets but I'm closely associated with two shooters that are; namely, Cecil Tucker and Charles Huckeba. During the past many years, I've studied everything I could find on the subject and I must say that it has been most enlightening. I have concluded, like so many others, that quality bullets are the most important component in the accuracy equation. Second, and a close second at that, is barrels. With a good barrel and what Mike Ratigan calls Superman bullets, a good shooter will be almost impossible to beat.

There are many, including my friend Charles Huckeba, that are of the opinion that bullet core stripping is nonsense and evidently you feel the same way. I have not conducted tests of my own but Harold Vaughn did extensive testing and described the results in chapter 8 of his book, Rifle Accuracy Facts. Who knows; maybe it is of no concern but of one thing I'm certain and that is thorough washing and drying of both jackets and cores before core seating is important. I'm also certain that core seating pressure is critical. Many bullet makers ruin otherwise perfectly good bullets by seating the cores to tight thereby stretching and damaging the jackets in the process.

Please continue to monitor this forum and share with us your knowledge. I agree with Bart Sauter when he says, "George Ulrich is a great, great man.

Best regards

Gene Beggs

 

[geo.ulrich]

George, thanks for taking the time to share your priceless knowledge and experience with the rest of us. I look forward to your posts about bullet making so much.

Please understand that I do not consider myself an expert on benchrest bullets but I'm closely associated with two shooters that are; namely, Cecil Tucker and Charles Huckeba. During the past many years, I've studied everything I could find on the subject and I must say that it has been most enlightening. I have concluded, like so many others, that quality bullets are the most important component in the accuracy equation. Second, and a close second at that, is barrels. With a good barrel and what Mike Ratigan calls Superman bullets, a good shooter will be almost impossible to beat.

There are many, including my friend Charles Huckeba, that are of the opinion that bullet core stripping is nonsense and evidently you feel the same way. I'm also certain that core seating pressure is critical. Many bullet makers ruin otherwise perfectly good bullets by seating the cores to tight thereby stretching and damaging the jackets in the process.

Gene, Charles hit the nail on the head, the days of Don Rorshach's screw down core seater until jacket pops and back off 1/8 turn are long gone and buried you WILL do more damage with to much core seating pressure then with less or should I say correct pressure. This separates the lets say good bullet makers from the great bullet makers. the great ones can make at least good bullets with crappy jackets the others can make bad bullets with great jackets. On to the barrel part my opinion is barrels mean more you still need great bullets but I have a friend that had an unreal unlimited barrel shot anything I even purposely made bad bullets just to see and thing still shot unreal.... George

 

[Gene Beggs]

Thanks George. I appreciate any time you'll give us. I wish I was thirty years younger and could justify investing the money in bullet making equipment as I find it fascinating. I don't shoot as much as I used to so I guess I'll just continue buying my bullets, but I'll continue reading everything I come across on the subject especially anything you say about the subject.

Later,

Best regards

Gene Beggs