Swaging bonded cores

[Jailer]

Finally got around to playing with my BT 40 to 45 swage dies again. I want to make some bonded core heavy weight bullets for my Bushmaster 450.

I got my cores bonded well, maybe too well. I'm having to run them through the core seat die 3 or 4 times to get all the wrinkles and depressions out of the sides. Is this normal for a bonded core? Or do I need to run the die down further for more pressure?

I may have to adjust the core weight down a bit as the seated core already has a little lead pushed out of the case after they are seated.

Also, should I be bonding only a portion of the core and then adding the rest when I run them through the core seat die or is bonding the whole core OK?

This is my first time attempting this so I'd love to hear from some members that have some experience with this.

[GRUMPA]

I'm just starting out with the same dies I think you have. Although I haven't gotten to the bonding aspect just yet. I have done a few hundred so far with pretty good results but that wrinkled issue you have sounds kinda odd.

When I do mine of course without bonding it seems do be doing just what its supposed too, first time every time.There is only a couple of things I'm curious about though. What are you using as a bonding agent? To be honest I've been doing everything but bonding, and I know you didn't want to hear from a novice at this but still it peaked my curiosity.

[Jailer]

I've made plenty that weren't bonded and none of them had wrinkles or depressions in the sides. That's why I was wondering if this is normal when trying to swage bonded core bullets.

I'm just applying paste soldering flux on the inside of the case and outside of the core with a Q-tip and then melting the cores with a propane torch. Slow, I know but I'm still experimenting with it.

[gjemba]

I solder about half of mine using the same method you are doing and don't have any wrinkle problems. I wonder if you are annealing the cases before you solder them? They are not hot enough to anneal properly with just the temperature required to solder. Annealing needs to be done prior to the bonding step.

Gary

[Jailer]

The cases were annealed before I started although I heated them until they glowed. They are annealed for sure.

[gjemba]

I add 1 more step that I forgot to mention. I use a seating die and the forming die. I don't do the 1 step method. I press the cores in the seating die after bonding them so the boolit is sized to full size before I run it through the final nose forming die. It sounds like you are doing the same thing so maybe you need to add more pressure. Other than that, I am out of ideas.
Gary

[BT Sniper]

:coffee:

Still waking up so a bit foggy. I have not done a lot of bonding yet but I may need a few more details. I imagine it is a 40S&W case. I don't remember if I sold you an expanding mandrel but are you able to expand the case to say .445 before you bond the core?

What weight core are you using?

The spent primer I'm sure is still in place? When the lead melts it will fill the void in the primer area, even with a spent primmer still in place. It doesn't do this when we don't melt/bond the cores so that will result in us needing to adjust the die a little fruther into the press vs. when we don't bond.

I still have a bit to learn about bonding cores too. I'm not quite sure about the wrinkles and depressions you are getting. any pics?

What is the comment about after the core is seated there is still lead exposed? That must be a core that was not bonded?

How much bonding agent are you using? The depressions could be from leftover or excessive agent that did not fully evaporate in the bonding process? usually 1 drop is all that is needed.

Yes you could bond only a portion of the core then add more to it in the core seat steep I would think. I imagine the hardness of the lead will make a difference in our ability to expand the 40S&W case to final diameter after bonding. Have you tried pure lead bonded?

I have wondered if a different style punch would be benificial for seating a bonded core. Like a long HP of sorts. I allways thought it strange that after we have bonded a core we further attempt to "seat" it further into the case after it is allready bonded to the case????? Seems conter productive to me??

I think it is just going to take a bit more R&D. I havn't done much of the bonding myself yet, certainly not in the 45s yet anyway. All I know is it doesn't take much of the bonding agent, experiment usign one drop vs. two, vs just swabing the inside of the jacket with a Q-tip diped in bonding agent and see if it makes any difference.

Good luck

BT

[gjemba]

:
I allways thought it strange that after we have bonded a core we further attempt to "seat" it further into the case after it is allready bonded to the case????? Seems conter productive to me??

BT


I don't run the the bonded core through the core seating punch for the purpose of seating the core, although it does even out the top of the lead due to a depression from heating the lead. I do it to expand the case to the full diameter so the nose forming die has less pressure on it and to minimize the chance that lead will flow by the nose forming punch. Every boolit is run through both punches, whether they are bonded or not.

This eliminates any voids in the core and I have no lead extending past the top of the case. I tried the 1 step method and noticed that lead extended past the top of the case once the nose was formed. With the same weight core run through the seating die, the lead is flush with the jacket after final forming. That leads me to believe there may be voids in the core if I don't seat the core first. Yesterday I compared my boolits to factory boolits of the same weight, both loaded with the same powder, and mind shot every bit as accurately as the factory units out of my TC Encore.

I use standard paste flux to bond the core. I just touch the core on the flux and drop it in the case.

Gary

[ReloaderFred]

My process and experience has been the same as gjemba's. I do anneal my cases with the core in place, but I don't add any flux for bonding, since I'm just shooting paper with them in my pistol calibers. I found that if I skipped the core seating, I got wrinkled jackets and lead where I didn't want it. I use pure lead cast bullets for cores (unsized and unlubed, of course).

The core seating just gives me a better bullet.

Hope this helps.

Fred

[BT Sniper]

Gary,

I agree on all you said! Only bullets that I ever recamend be attempted in one step is the 40 and 44. The rest should be made as you discribed and like all other convential bullets with the core seat followed by the point form die. Thanks for clearing that up. It did seem like I was addvising skipping the core seat step. Certainly didn't mean it that way. I just need to experiment a bit more with bonding.

Glad to see you bullets are shooting everybit as good as factory.

Good shooting and Swage On!

BT

[Jailer]

I don't run the the bonded core through the core seating punch for the purpose of seating the core, although it does even out the top of the lead due to a depression from heating the lead. I do it to expand the case to the full diameter so the nose forming die has less pressure on it and to minimize the chance that lead will flow by the nose forming punch. Every boolit is run through both punches, whether they are bonded or not.

This eliminates any voids in the core and I have no lead extending past the top of the case. I tried the 1 step method and noticed that lead extended past the top of the case once the nose was formed. With the same weight core run through the seating die, the lead is flush with the jacket after final forming. That leads me to believe there may be voids in the core if I don't seat the core first. Yesterday I compared my boolits to factory boolits of the same weight, both loaded with the same powder, and mind shot every bit as accurately as the factory units out of my TC Encore.

I use standard paste flux to bond the core. I just touch the core on the flux and drop it in the case.

Gary

This is the same process I am doing. I have the 2 step dies; core seat and point form with a HP nose punch. They are BT's re worked CH 45 dies.

I'm guessing, and this is nothing more than a guess, that the core is bonding very tightly in spots and not letting the brass swell causing wrinkles and depressions in the outside of the case. I don't want to put more pressure on the core seat die as I'm already pushing lead out of the top of the case now when seating the core. Usually a few trips through the core seat die and they are better but some just won't get rid of the wrinkles.

I may just have to try a lighter core. It may be that I'm using too heavy a core and it's just too much lead for the 40 case. My cores are cast from pure lead.

BT, I sent my check out for the flat nose punch so you should be getting it soon. A little lead exposed at the tip with a flat point might actually work well for what I'm trying to do. I'm wanting a bonded core bullet for the 450 bushmaster so they bullet will hold together at higher velocities. A 285 grain flat nose bonded core should make a good hunting bullet once I get this figured out.

I'll try and post a couple pictures in a little while so you all can see what I'm talking about.

[Jailer]

Here's a pic. Kinda hard to see in the picture so I'll describe as best I can.

One on the left it looks like a dark spot in the center on the right hand side. That's a depression where it didn't fill out. The one in the middle has a few of them just like that in the center of it. The one on the right has been point formed and still shows one in the center on the right hand side if you look close. All of these had 3 or 4 trips through the core seat die.

An anomaly to bonding cores or is this normal?

http://i19.photobucket.com/albums/b180/Jailer/posting%20pics/wrinkledbullets.jpg

[BT Sniper]

Jailer,

Good pics. To a trained eye yes it is easy to see. I've got some ideas. I may not have noticed if you allready posted it but a couple questions

1. what are you using for core bond agent?
2. how much (volume of bonding agent, not cost) :)
3. what core are you using? weight? diameter?
4. how are you applying the heat to melt the cores? dirrect flame? From the top or bottom of the case are you appling the heat? are you dirrecting teh heat primarly to teh lead first, case first, both at same time? etc?
5. is the spent primmer in place? Kind of a silly question but BDBullets was able to melt the cores inside a jacket without the primer in place on his 41s. Was very cool looking.

I'm guessing you may have trapped air pockets caused by any number of possible reasons. I have noticed that depending on how we apply the heat to melt the lead makes a difference. If the top of the lead melts before the bottom it creates a dam trapping the air beneth. Could also be trapping a bit of the bonding agent. Too large of diameter of cast boolit core can also cause this problem. Of course this is all speculation on my part but there is a lot of different tryle and error techniques to try till we find the way that works.

You will notice this air/gas escaping from the case as the lead melts. Imagine pooring concrete and workign out all the air I suppose. Maybe if we could slightly stir the melted lead in the case to be sure teh air is gone. Sounds like a bit much but if trapped air/gases is the problem finding teh problem is half the battle.

I'll try to find some of the bullets I made way back when that I bonded. I know I made some 44s. I'll check.

keep us posted. I bet results will be awesome. I'll have your new punch ASAP.

Brian

[ReloaderFred]

I'd like to see a picture of the mouth of the case from the top. I'm thinking the core seat punch isn't fitting tightly enough inside the case to produce enough pressure to iron out the dents. I've been using the Lee push through stems for some of my core seating, choosing one that fits rather tightly inside the case. This means seating the core into the case with the case upside down. The punch goes inside the case and if a good enough fit, will provide enough pressure to completely fill out the case/jacket.

Hope this helps.

Fred

[BT Sniper]

That is a good thought too. I know I made the core seat insert with a bit of taper for use with lighter bullet and long jackets. Try the two flat punches with eonugh lead added after bonded to fill case to rim. Or a tighter base punch may be in order. Do you have a 44 cal swage punch? You can insert the case in your core seat die up side down and use the 44 punch to seat the core. I think anyway :) somthing to try.

BT

[Jailer]

Ok some answers to your questions first.

1. what are you using for core bond agent? Paste soldering flux applied with a Q tip
2. how much (volume of bonding agent, not cost) Just enough for a very light film on the entire interior of the case.
3. what core are you using? weight? diameter? I drilled a 2 cavity Lee 148 TL wad cutter mold. I added length to the cavity, not diameter. Made sure there is plenty of room for flux to escape. Weight ended up at 213 to 214 grains.
4. how are you applying the heat to melt the cores? dirrect flame? From the top or bottom of the case are you appling the heat? are you dirrecting teh heat primarly to teh lead first, case first, both at same time? etc? Direct flame from a propane torch directed at the base until the core melts completely. Then even heat over the entire case until the case glows.
5. is the spent primmer in place? Kind of a silly question but BDBullets was able to melt the cores inside a jacket without the primer in place on his 41s. Was very cool looking. Spent primer is in place.

I think you might be on to something with the trapped air. Air compresses and would leave a mark like that. I never thought about that. I might try melting some in my old gas grill that I use to anneal the brass tonight and see if that makes a difference. Slower temp build over an hour might just cure that or at least eliminate the possibility of trapped air.

Fred, are the Lee punches strong enough to hold up to swaging pressures? I thought I remember someone posting pictures of one they buggered up using it to seat cores.

Those are some great ideas guys, thanks. That's why I posted this here. You both have given me a couple things to check out that I would never have thought of.

[BLASTER62]

I'd like to see a picture of the mouth of the case from the top. I'm thinking the core seat punch isn't fitting tightly enough inside the case to produce enough pressure to iron out the dents. I've been using the Lee push through stems for some of my core seating, choosing one that fits rather tightly inside the case. This means seating the core into the case with the case upside down. The punch goes inside the case and if a good enough fit, will provide enough pressure to completely fill out the case/jacket.

Hope this helps.

Fred

Fred is right on this, also a thing to look at is the amount of lube you use. All that is needed is a small amount on your fingers,with soft brass or copper it is easy to over lube & dent & wrinkle jackets.

[Jailer]

Unbonded cores seat just fine no wrinkles. It's just the bonded cores that are displaying this.

[BT Sniper]

Well I'm a bit stumped. Your process sounds pretty good to me. You know it might not make a beans worth of difference in the performance/ accuracy of the final bullet. May be only cosmetic. Only testing will tell. Maybe a different punch, maybe try the 44 swage die base punch as I mentioned if you have it??

Think it is going to be a bit of tryle and error.

Good shooting. Let me know if you need anything.

BT

[BT Sniper]

Are you getting a good bond? There will be a crater in the center as viewed from top after the lead cools. Heck try more flux see if you can recreate the voids on purpose to an extreem. I am pretty sure I have achieved better results with corbins corbond vs other attempts. It was only $7 for a bottle that will last a long time.

The lee punches will work for a short time. I was the one that posted the broke and bent ones. may cause harm to the shell holder slot of the ram too???

[ReloaderFred]

Jailer,

If you're careful with the soft Lee punches, and don't hit the mouth of the die, they work pretty well. They aren't hardened at all, so they do ding pretty easily if they come in contact with the die itself. I've used one .40 caliber punch to seat over 2,700 cores for the .44 caliber bullets I'm making. It fits snugly inside the .40 S&W case and seats the cores just right.

I took the possibility of ruining the soft punches into consideration when I ordered the punches, so I ordered 4 of each size I thought I would need. So far, I've only ruined one punch, and that was my fault. For $2.50 each, I figured they were a good investment for the experiments I had in mind with the swaging I'm doing.

Hope this helps.

Fred

[Jailer]

You know Brian I think you may have been on to something with the trapped air idea. I was using quite a bit more flux when I first tried these. Last night some of the last few that I did, I tried much less flux. Just barely enough to coat the interior of the brass. They are bonding good and I am getting a depression in the center when they cool.

I just went out and seated the core on one of the ones I did last night and it seated fine with no wrinkles first time I tried. I think I may have been using too much flux on the ones I previously did and trapped some air bubbles from the boiling flux. Take a look below. The lead was flush with the top of the case before I seated it and it still stayed stuck to the sides of the case when the center of the core was pushed down and the case swelled to 452.

http://i19.photobucket.com/albums/b180/Jailer/posting%20pics/wrinkledbulletssideview.jpghttp://i19.photobucket.com/albums/b180/Jailer/posting%20pics/wrinkled1.jpg

I think more experimenting is in order but I'm betting now that was the problem.

Now I'm really itching for that flat point nose punch. :-P I bet with a very light notch in the jacket and a small amount of exposed lead flat nose tip with the bonded core these things will perform great.

[BT Sniper]

Sounds and looks like everything is better if not Great! I'll get the punch out in this weeks mail. Those look good. Going to notch them? :)

Jailer, I'll send you a PM on that flat punch. Make sure we are all measuring from the same spot.

Swage on!

BT

well now that I read your post again you had the same thoughts I did. With a notch and exposed lead tip those will be awesome bullets. How fast you figure you will get them up to FPS?

[Jailer]

I'm figuring somewhere around 1800 to 2000 FPS out of a 16 inch barrel.

I'm thinking just enough notch to get the jacket to separate in even petals will do the trick. The HP's turned out OK, but there is just too much core being pushed out to make them work. A flat nose will still deliver the "hit" and should create a nice shock wave and wound channel. With the thin jacket and bonded core I'm expecting some pretty dramatic expansion and hopefully good weight retention. Time will tell.

[BT Sniper]

Yep I have got predictable expansion along the exact spot of the notch with even the smallest of notches applied. The long notches just look cooler. 1800 - 2000 should do nicly. Keep us posted.

I sent you a PM. Get back to me with a quick reply.

Thanks

Bt

[BT Sniper]

I haven't tested any 45s but here is a .458 from 45 ACP at 425 grains shot out of 45-70 marlin at a max load. I bet your results may be similar, possibly even better. This one wasn't even bonded, had a wheel weight core and was shot into dirt.

http://i636.photobucket.com/albums/uu87/BTSniper/458s002jpg.jpg

http://i636.photobucket.com/albums/uu87/BTSniper/458s006jpg.jpg

http://i636.photobucket.com/albums/uu87/BTSniper/458s005jpg.jpg

BT

[garym1a2]

What you are trying to do by bonding cores with the flux and high temp is basically a solder operation. You can get entrapped flux. In electronics soldering we have some tin in the lead to get better flow. A key solder for semicondictor power transistor assembly is 95pb/5sn with a melt temp in the range of 305C. To get a really good solder joint we tend to use an atmosphere of pure nitrogen or better yet 95Nitrogen/5%hydrogen.

With the lower temp solders like 63/37 (183C)you get much better wettings but will cost more and have a lower weight.

[Jailer]

Ballistics are very similar to the 45-70 so it should be interesting how these turn out.

I bet if I could get my hands on some cheap 10mm brass I could make some real heavy weights.

[BT Sniper]

10mms $$$$, size down the 45 ACP, cheap and easy! Smaller web of the 45 makes it pretty easy to size down. I made a 300 grain xtp 44 cal from a sized down 45acp once. Your .452 is only .006 smaller then the 425 grain bullet pictured above. Go for it!

BT

[Jailer]

What are you using to draw the 45 brass down before you swage it?

[MightyThor]

Might try to melt your weighed core in a crucible or ladle and then pour liquid into your heated, prepped and fluxed case. You shouldn't get any air bubbles this way. Another option would be to dip a hot soldering iron or even a hot nail into your liquid core. This would agitate any trapped air or flux an bring it up but would keep the lead from sticking to your agitator (might be some initial tinning, but by the batch you should still get consistent weights)

[BT Sniper]

What are you using to draw the 45 brass down before you swage it?

Ahh.... that is the challenge. At the moment it is only custom sizing dies. There has got to be a taper crimp or roll crimp die that is close to .450ish. I think my 44AMP sizing die is pretty close to that. Maybe a 44 sizing die of some sort might work? If not it is custom made options. I know just the guy :)

BT

[ReloaderFred]

BT,

Todays price on cartridge brass is $2.18 a pound at Pacific Recycling, in Eugene. Maybe it would be worth a road trip for you to turn some of that brass into cash............

Hope this helps.

Fred

[BT Sniper]

That's a thought.

Thanks Fred

[Grandpas50AE]

Jailer,
I apologize for not coming into this thread earlier, but the last two weeks at work have been very long and tough ones and haven't left me any time for personal stuff. Anyway, I had similar problems when I first started bonding .223 bullets. Initially I was using drawn-down .22LR rimfire brass, and getting both the wrinkle problem and the lead up around the core seat punch. I discovered that I hadn't let the lead cores stay hot and melted long enough for all the steam of the flux to escape and bubble out, leaving air pockets. Once I started keeping them hot long enough to let the flux completely turn to steam and the steam escape, the problems went away. For a flux, I used the Corbin core bonding flux. I also discovered that I was using a little too much in the beginning, and began using just enough to get the job done. The Bonded boolits I make now, both in .22LR jackets and in J-4 jackets are as perfect a little pill as one could hope for. Using the same cores of 55 grains, the .22LR jacketed ones come out at 65 gr., while the J-4 ones come out at 69.5 gr. My point forming dies is a 6-S spitzer. Hope all this helps.

[PbHurler]

Jailer,
I've got to agree with Grandpas50AE. I think the core is not molten enough. Here's some of my experiences while bonding cores. A few caveats here; I'm using J4 jackets, 99.98% chemical lead, Corbin Core Bond Flux. I use two eyedropper drops of this liquid flux. When I melt the cores, I watch for what I call core "Rollover". What I mean is; I can watch the top of the core cylinder suddenly collapse at the same time a bubble of trapped air & flux residue "bloops" up to the top. Upon cooling a meniscus will form on the top of the core and a shrinkage void appears from the center down into the core. (There's no sprue to draw from during cooling like when we cast). Years ago, I called the professor of metallurgy at the University of Oklahoma and asked how I might prevent this void & he said I might try using a greater thermal mass to slow down the rate of cooling. Perhaps a drilled brass "loading block" in a heat treatment oven. (Beyond my wallet). When you seat the cores, the void becomes almost a homonogous mass, just not solid. (Think of seating lead shot in a jacket) You could use a hollow point punch while seating the core to even-out the void if you wished. I've made .30 & .44 cal. bonded cores and a good core seat after bonding has produced some pretty darn good bullets, they are accurate & darn sure bonded . The .30 cals. can be topped off with a short non-bonded core for point forming purposes if need be. Hope this helps.

[shaggist]

To eliminate the problem I was having with trapped flux and air keeping my cores from bonding properly, I started by removing the primer and then melting the core into the jacket on top of a piece of asbestos sheet. You can use anything that is fire-proof, such as a paving tile. The lead filled the primer pocket, but was nicely flattened where it contacted the asbestos, and the core bonded perfectly to the jacket. Testing by firing into water-filled milk jugs and water-soaked phone books showed everything to be exactly as I wanted and expected it to be.

[Grandpas50AE]

PbHurler,
A few fire bricks purchased from a brick company for 4 or 5 bucks a piece will do as a block just fine. Use a masonry drill bit to drill a slightly over-size hole approximately 1/2 the jacket length and they will stand up as you heat them. You can get quite a few .223's in a standard sized fire brick, and it costs very little.