jackets from coiled tube

[parkerhale1200]

Hello,
Does anybody or is anybody using "soft" coiled tube for making jackets?
And are the results good, rather fair or not worth trying it.

Thanks in advance

[just bill]

Check out the sticky "My 30 cal setup", lead chucker has a good thread about coiled copper tubing.
Justbill

[clodhopper]

The original Barnes bullets were made from soft copper tubing and soft lead cores. On impact with large fleshy creatures they held together well and penetrated deeply.

[seppos]

Coiled tube works well as well as the Barnes Originals. Shot one moose little over year ago with my 45-70 from about 200 m and it only walked about 15 feet after shot.

Long shot maybe but it was nesessary to do as the moose was suffered enough.. It has been in accident with car couple of months ago and had a broken leg, The constant infection in its body had also triggered an virus infection and the whole body of that moose was covered with blisters.. Some where badly infected and the smell was.. Dont actually want to tell.. Here is the pic from that poor animals head after I put it down from its miserys..
183749
S

[parkerhale1200]

@ just bill, i just reread the tread, and i though it was hard drawn copper, never the less, very Very VERY nice work.
I have a somewhat bigger lathe but my skills are....lets say i am a old fashioned type carpenter.
However i made a device to straiten coiled copper tubing and some casting molds.
And a "clamp" that can hold 12 tubes in place to cut to length with a stronger chopsaw.
Its easy to feed, easy to adjust the length and very easy to dispose the ready ones, under 20 seconds i am ready for the next 12.
All from aluminium.

But how do they preform at 200/300 target practise.


@ clodhopper For hunting i use mostly cb s, but the barnes fact surprises me, it gives also away that those are hard bullets on impact


@ seppos, I can imagine the smell, thrust me, nice and good shot from a 45-70 over 200 meters, good thing for the moose

[clodhopper]

I'm thinking the heavy wall, copper tubing, lead core bullets are tough. They would deform, but retain their weight.
Accuracy may not be up to today's long range standards.

[just bill]

parker the thread may not have actually said coiled (soft) copper, however I had been exchanging PM's and that was in one of them.
Bill

[Valornor]

I bought some soft copper tubing to try. The Corbin swear it's not good for bullets, but I haven't done anything to check concentricty or try to make bullets from it yet. I have made a few lots from hard copper tuning but didn't get good accracy from them. About 2 MOA and the grouping suggested that the bullets were unbalanced likely jacket concentricity issue.

[Lead pot]

It makes some difference if your using soft copper in type K, L or M but yes it is usable as well as red brass faucet supply tubing. Yellow brass tubing is a little brittle and must be annealed to get it to close the base well.
Actually soft copper is a lot easier to expand if you need to get a closer fit for the caliber.

[Valornor]

Good to know. The hard copper tubing I used is the the stuff I bought from Corbin when I got the Dies. I don't know what it is, tho now I am curious.

[uncle dino]

Val ..what caliber did you make the tube jackets for? I've had great success making tube jackets for the larger calibers. i use hard tube..I wonder if tiny amounts of runout in jacket is magnified in smaller calibers. D

[Valornor]

I used it to make 285gr .338 cal and shot them out of my .338 Lapua.


I am going to play around with them more. I did take some measurements on the tubing I was using and measured about .003 variation in thickness.

[uncle dino]

I've been making 350 grain, 50 cal for several Beowulf shooters..sub 1 inch 100 yd groups from the serious shooters of the bunch...but I think the difference is. Short for caliber work very well..those 285's are very long for cal. D

[Valornor]

Couple that with slower twist rates and typically slower velocities, it would make sense. The bullets are long enough that I have a hard time drawing out the jackets.

[uncle dino]

Good point..I hadn't considered that..d

[seppos]

If you draw the cup down with properly fitted tools, that will also homogenize the jacket walls.

S

[Valornor]

That is one thing I haven't checked yet. What the concentricity is after draw.

[seppos]

The tube in normal use does not need such a precision in wall thickness. In bullet making that is needed if the need is for accurate bullets.
In cup making the tools are made so that there is always a little reduction in the wall thickness after each drawing. That way the jacket thickness stays homogenous in all sides.

Same rule applys to the tubing jacket. If you reduce it gradually in the end you have homogenous jacket walls.
The bottom might have small thickness variation, but that should have smaller impact to accuracy than the one in the wall..

S

[Valornor]

Typically that is with a free float punch. The Corbin tubing jacket maker doesn't have a free float punch, so I suspect that there isn't much of a change in wall thickness.

[seppos]

Yes.. and they are aware about that and also inform customers that the tubing jackets might not give such a precision as the drawn jackets.. Good thing is that they have ready made jackets for sale so that the customers have the possibility to produce accurate bullets.

S

[Valornor]

Unfortunately not in .338 Cal. Largest they make is .308 cal. Being new to swaging at the time I didn't know that. But I have had conversations with Richard Corbin about making a free float punch and draw die set for drawing down 408 Cal jackets to .338. So I'm working with what I got.

[seppos]

Yes. Richard makes exelent stuff.
You could use that set to draw the tubing jackets also. Put to that same order some additional punches so that you could draw different jacket thicknesses.

S

[uncle dino]

Val. All my jacket draw dies have a spring loaded holder that holds the jacket on the center of the punch. Then the jacket is pushed into a stepped pocket in the bottom of the draw die. It centers jacket in the die before it is drawn..d

[Valornor]

That was my plan.

If I had to do it all over again, I would have done things a little differently in terms of ordering tooling. Lesson learned.

[seppos]

"Money is never wasted in steel" as the old mentor of gunsmithing used to say.

S

[Valornor]

True, I've learned a lot.

[seppos]

This is why we have this fine forum where to exhange ideas and experiences.

S

[goblism]

I used to use my set for making 45 cal from soft coiled copper tubing. Worked great just don't have the time to use it much anymore

[Vagabond55]

Been making .308 and .312 from 5/16 soft coiled copper tubing for several years now. It is time consuming, but the accuracy (from several users) averages somewhere between commercial soft points and match bullets.

[ohnomrbillk]

However i made a device to straiten coiled copper tubing



I'm very interested in your device to straighten copper tubing.

Could you post some pictures with a description?

[parkerhale1200]

ohnomrbillk
sorry, i am not very good with computers, to take a picture and email to photobucket or something.
Several (10-12) years ago on a other forum i maneged to do it, dont ask me how i did it.
"my" straightener looks very similar to those two in the links below, with two different things in the lay out
My divice contains three rows of eight wheels in a Mercedes shape star, and the last set of wheels i can adjust to thightin it more.
I can simply remove them and add some bigger diameter wheels into them.

I hope this is/was helpfull,

https://www.youtube.com/watch?v=7h_Q7gOnKcU
https://www.youtube.com/watch?v=RiFm1GUS7as

[Ballistics in Scotland]

I believe impact performance with coiled tube jackets would be fine. unless you are trying to duplicate the performance of dangerous-game solids. What I seem to remember seeing a Corbin document warning about, a long time ago, was a threat to accuracy - not a big threat, and I don't believe they said "don't". but not negligible. Of course Corbin commonly work for bulletmakers who consider nothing at all negligible.

###my own interpretation is that when you bend a tube, you stretch the outside of the curve thinner snd squash the inside of the curve thicker. Then when you straighten it, you don't exactly reverse the process. Some of it migrates around the edges instead, from outside to inside. This may just be my overactive imagination. I would do it if I was just interested in hunting, but I would do some statistically valid testing of the results before serious use.

[roysha]

When I was in gunsmith school in the late 60s one of our instructors, Bill Prater, told of visiting Barnes Bullets sometime in the 50s when Barnes was still at Bayfield. It seem that Barnes used the coiled copper tubing and to draw it down for a specific caliber he had a die of the correct diameter mounted in a frame of some sort. He would take a hammer and pound down the end of the tubing until it would go through the die far enough to be able to be clamped. The coil was unrolled and lubed with axle grease. The clamp was hooked to an old PEPSI truck and he would take off pulling the tubing through the die. I remember this story because of the PEPSI truck part. I asked what the significance of the PEPSI truck was and he told me he didn't know. I don't know if this story is true but given the time and ingenuity of folks of that era, I more than half believe it.