Simple jacket making dies and press

New to Cast Boolits and just starting my adventures in jacket making and swaging. My goal is to start from scratch and learn what it takes to make an accurate .264" bullet. I've built a prototype rig based on a 2 ton arbor press. I've designed the basic dies and had them CNC machined by a online prototyping company out of AISI 1018 steel which will be carburised to about 50 RHC and further polished. The punches are off the shelf HSS rods in 0.1mm increments. All I've done is grind a radius and polish an ever slight taper. The punches are held by a ER20 collet fitted to the ram. I'm using 1" blank discs from .0275" copper sheet that is fully annealed. My swage lube is a 50:50 mix of castor oil and pure lanolin. So far the results look promising. I have managed to form a complete 1.3" .262" jacket with very little effort. I'm now starting to build some measuring gear to really attack the wall thickness and concentricity control and hope to make some improvements on the set up. Eventually I will look at something that resembles the Wilson straight line dies. Slow but very accurate. Once I'm happy with the jackets I'll start looking at swaging gear. In the meantime, I'm really enjoying the process and hope to learn and share more on the forum.

wow, wish you were my neighbour, I could learn a thing or two..

Impressive first post. Love it when someone thinks outside the box a bit and tries something different. Please keep us posted.
Ron

What are the flat iron pieces with machined notches at the bottom of picture #2 for? I can see the punch elongating the formed tube/s by driving through series of dies to reduce diameter and form jacket in steps. But I am not tracking that the "Flat Iron" pieces are for.

P.S. Enjoying the thread.

Hi Mustang, The "flat iron" pieces I think you refer to are the stripper forks. Once the jacket has formed, I need to strip it of the punch. The design allows me to simply push the stripper hard into the punch and then lift the ram. The jacket just falls off.

OK - I understand. On my Corbin dies; the "Spring Back" of the Copper/Brass is what strips the in process jacket tubes off the punch. From a simplified die process/ I like the dies and means of removing the in process jacket tubes from the punch. Thanks.

The push through dies I have made have a slightly larger diameter after the sizing has been done. This allows the edge between the larger and smaller diameter to grab the jacket and strip it off the punch when the punch is withdrawn. The next jacket pushes it out of the top or bottom, in your case, of the die.

What do you plan to adjust to improve concentricity of the jacket, if necessary? With a round die and a round punch, I don’t see much to adjust except the diameter of the punch, but that would change jacket thickness, and length, but I am not sure how it could influence concentricity.

Hi Garandsrus, You raised a good point about the edge of the larger and smaller diameter. I had a similar feature in the base of the die but it seems that the punch was still holding onto the jacket. I ended up just using a stripper as a fallback solution. The improvements I hope to make are mainly with the alignment of the punch that is solidly fixed to the ram. If the punch is not 100% aligned with the die center there will be error. I plan to float the punch laterally and have a punch guide above the die. This will hopefully get a better result.

Thanks for the response. Corbin uses a floating punch with their swage dies so you probably are on the right track. I don’t know what they do, but J4 jackets are supposed to be about the most concentric there are at less than .0003 wall thickness variation.

Interesting.
No 6.5mm boolits in Straya either?

Well done Sir, Your forming dies look very much like Drill guides and I once wondered if they may be available in the correct size for at least some dies. You have certainly thought outside the box for sure and look forward to your results. Regards Stephen

Hi Marky123, there are 6.5mm bullets down here but at ludicrous prices. Match projectiles start around AUD$0.80 each. That includes Berger, Sierra and Lapua. Not uncommon for Sierra MK 142 grain at $1.15 each.

Hi Stephen. Thanks for the comments. I originally looked at everything that resembles a die that could be easily tweeked, modified and adapted. However.......I did lots of reading into deep drawing tool design and realised its a bit more complex that first imagined. The internal die profile is critical firstly for reduction ratio and secondly, the ironing ratio. The copper cup is reduced in diameter by several steps of 21-22%. The elongation in each step that thins the jackets (ironing) is controlled by the punch diameter at approx 17% oversize of the internal jacket diameter. Then the each die needs a profile that will allow the copper to flow without the punch breaking through. In the end I decided to draw up all this on CAD and then have the profiles machined on a CNC machine. From the outside they look simple but there is a fair bit of working out on the inside. I was both surprised and relieved that the first jackets actually worked considering it was all very much theoretical. I'm now working on a new set that addresses a couple of issues of the prototype dies. The original die holder was not up to the job and now I've used a threaded die holder with a taper. This allows the die to pull in concentrically when tightened. Hopefully I'll have some photos when these are up and running

Are you annealing between draws?

Hi Sitzme,. I am only annealing the copper strip prior to disc blanking. On all cup and draw stages there is no annealing. I originally thought I'd have to anneal by the second draw but the jackets have held together ok. I will still have to anneal prior to swaging later down the track.

If for some reason your swaged bullets are not as accurate as you want may I suggest you anneal at least after every second step as while you may still be able to form the bullets you maybe getting uneven jacket thickness due to hard spots forming in material. I was told this by an old mate who has since passed and did make some very accurate bullets. I can really appreciate how your thinking things out and look forward to you eventual success. Regards Stephen

Hi Stephen, duly noted. I still reckon work hardening will be one issue that will need to be dealt with. I plan to run another batch soon and will try a few with a second anneal. I've also set up a dial gauge with an anvil so I can spin the jackets to measure wall thickness variations. The second batch with a few set up changes got me around 0.0008"average. A long way off J4 and sierra tolerances but keen to keep trying

What size strip are you using for blanks? I know someone who has 20 x 50 kg coils of proper 95-5 , You would get it at around scrap or cost price...

Hi M.A.D, I'm using 30mm wide and 0.70mm thick C12200 strip fully annealed. Wow...a tonne of gilding metal. That would last me several lifetimes. I'm planning to just make bullets for my own consumption so I intend to buy in smaller quantities. If its the right size I might be tempted to buy one coil.

Hi Andrew,
Malcolm Bone, @ Taipan Bullets Australia has some copper gilding metal (ex Germany) in 1” wide x 0.035” & 0.70” wide x 0.025” thick, as he is no longer making bullets available for sale
Cheers

Thanks for that Copperman. Shame about Taipan. Only really leaves Woodleigh and Dyer (now Optimus) here in Aus. The 1" strip is a bit too narrow. I'm cutting 1" discs at the moment to get a 1.33" jacket in 6.5mm. The goal is to get a consistent 1.25"ish jacket for a 115-120 grain flat base with a 7.5 ogive. So far I've been annealing sheet and guillotining into 30mm wide strip.

Andrew six point five. I too want to make jackets but I'm just starting. what references should I look for. You mentioned the ironing rate and the step down percentage. Where can I go to learn things like that? I have access to a full machine shop with CNC, EDM, CMM. Etc

Hi ShaneJ45. I can assure you that there is no place to go to learn about jacket making. Read as much as you can online on deep drawing especially copper alloys. But first create in your head a specification of what you want to achieve. This determines how much time and money you want to throw at this. I started simply by experimenting and prototyping with readily available tools and materials to see what happens. That's why my dies and press look nothing like what's commercially available. I just came at it with a different mindset. In the end the CNC machining work and final die designs are a refinement of my first experiments. There are a few good posts on here on by others that are having a go. I loved reading KTN and Zbench posts. Start with reading deep drawing techniques and the design guidelines. There's heaps on the web. The issues of step down and ironing are well documented. You then have to create a detailed specification for your calibre and length of jacket and the preceding drawn cups and jackets. Mine was sketched out at first but proved invaluable later on, attached is a scan. This information was continually added to and updated on CAD. Also most if it is metric!! Also attached is a simple die profile I found on the web. Although its for a big ferrous part, the profile can be adapted and scaled. This formed the basis for my die designs. The main thing is to have a go and enjoy the rideAttachment 289117Attachment 289118

Here are some of my die drawings as a reference

Attachment 289119
Attachment 289121

Thank you for posting I have been thinking on the same thing does the 2 ton press do well for you?

Hi Firefly, yes the 2 ton press works just fine. I added a 2 foot bar instead the one supplied. All the force needed for cupping to final draw. The blanking though requires either higher tonnage or a modified punch with shear angle to reduce the force needed.

Thank you I was looking at presses Might go 3 ton Have considered making a Hydraulic press but cycle time would be slow with parts I can afford!
I saw a 3 ton press for $279 might get one in November .

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Originally Posted by firefly1957

Thank you I was looking at presses Might go 3 ton Have considered making a Hydraulic press but cycle time would be slow with parts I can afford!
I saw a 3 ton press for $279 might get one in November .

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You could try air power if you're concerned with speed. I'm currently looking for a local shop to machine the CB swage press, and adding an air cylinder is a modification I'm considering jumping into later on.

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