Another Bullet Making Thread (lots of photos & video)

[D Coots]

Several years ago guys thought the jackets were too hard and didn't form right. Not sure if anyone is still annealing
or not.

Maybe George will check in.

 

[RGRobinett]

Though late, Thank You, Lee, for an excellent thread, and great photography.

Regarding "annealing" - I do not believe we want "dead-soft" jackets, but rather stress-relieved, malleable material. George Ulrich was very generous sharing the info needed to properly draw the jackets back to a very workable "hardness" - on the long/heavy for caliber, high BC bullets, and J4 jackets, this eliminated bullet failures. A fringe "benifit" is nicely formed, uniform meplats.

For many years, I have been "drawing back" J4 jackets: all jackets which will be made into BT configuration, and any LOT which has a tendency to "fold", or, fracture during point-up. For BT bullets, this is done following preforming, or, partial preforming of the BT. For the LOTs which 'want' to fold, the draw-back [fix] has proven slightly better than a coin-flip.

Following physical drawing to size & length, Sierra Match King jackets are "drawn back", by being run through an oven. Passing through the open-air conveyor oven (perhaps 40 feet long), the jackets are oxidized and quite ugly: upon falling off of the conveyor, they have the appearance of a tarnished penny.
Sierra's process of chemically "washing" the jackets cleans them back up to a nice shine.

I believe that, following work-hardening due to forming, the excellent Hines Precision/Tactical jackets are also drawn back. Both Sierra and Hines are more subject to tarnishing than are J4. Lab testing of the jacket alloy for the various jackets has come back with Sierra and Hines right at the gilding metal (bullet jacket standard) 95% Cu : 5% zinc; J4 have ranged from 92:8, to 90:10. That said, I have not had jackets analyzed for several years, and these attributes could have changed.

All three brands make excellent BR quality bullets: for "point-blank FB bullets, there is nothing to gain by drawing back, or, "annealing", however, it certainly doesn't hurt . . . don't take them back to "dead-soft'! RG

P.S. Here's a link to some comparatively amateurish, unscripted videos of drawn back/"annealed" jackets, and how to quickly remove the tarnish. < https://bibullets.com/bullet-making/ >

 

[PaGreg]

Great stuff Lee. When will you be doing a DIY “primer” tutorial?

 

[andrewc6.5]

Thanks everyone and thank you Randy for the link and insight. I have been trying to find out more about the materials and processes of the jacket manufacturers. Heat treatment and its effect is the missing piece to me so far. Its great to see bullet production using the kitchen stove and utensils. I have warned my girlfriend not to use the slow cooker pot in the spare room. I can get a temperature of about 430 deg F in my kitchen oven to stress relieve but not anneal (requiring over 800 deg F). My bullets will be a long .264 flat base at about 130 grains so yes, the stress relieving issue will be important as discussed. When I decided that I wanted to swage my own bullets the issue of jacket availability especially .264 jackets was the greatest concern. I'm down here in Australia so the situation is even more dire. During our Covid lockdowns I had a bit of time to experiment and build some prototype tooling for making jackets based on an arbor press. The latest dies and punches are producing reasonable jacket concentricity which for me will make an ok "match" bullet but not in the bench rest league. I chose to source fully annealed C12200 pure copper instead of gilding 90/10 because its easier to obtain here.
When I finally get to start swaging I can try a few options. Anneal before the last jacket draw (.261") which can give a semi hard jacket prior to swaging or stress relieve prior to swaging on a hard jacket or a combination of both. I know I've complicated my life and added more things to consider but hey I enjoy the challenge. Attached are pics of the project so far.

 

[RGRobinett]

Now, that is dipping BOTH feet into the deep end! I'm Presuming that you made your own draw dies - nicely done.
If you haven't already gotten to the shooting, and your jackets are <0.0005" wall thickness variation, you will likely be pleasantly rewarded with precision grouping. This is especially true when you have a grip on the material properties.
I do not want to hi-jack this GREAT thread, but am keenly interested in your project - please begin a new thread, keep us posted regarding your results!! RG

 

[andrewc6.5]

Now, that dipping BOTH feet into the deep end! I'm Presuming that you made your own draw dies - nicely done.
If you haven't already gotten to the shooting, and your jackets are <0.0005" wall thickness variation, you will likely be pleasantly rewarded with precision grouping. This is especially true when you have a grip on the material properties.
I do not want to hi-jack this GREAT thread, but am keenly interested in your project - please begin a new thread, keep us posted regarding your results!! RG

Appreciate the advice! I'll put something together in the coming weeks. cheers

 

[WIB3]

This draw back procedure is quite interesting to me. I am making 103gr BT’s on Sierra jackets. I am pre-forming the BT both on the jacket and the core. I am curious as to weather the cores can be stressed relieved at home in the oven prior to core seating. Temps and times would be helpful.

 

[Fuj]

This draw back procedure is quite interesting to me. I am making 103gr BT’s on Sierra jackets. I am pre-forming the BT both on the jacket and the core. I am curious as to weather the cores can be stressed relieved at home in the oven prior to core seating. Temps and times would be helpful.

You'll need to be 700 degrees or more I believe. Practical Machinist had
some good threads on the subject.

 

[WayneShaw]

Most bullet cores are pure lead or with a small amount of antimony. Lead melts at 622 degrees, so you would have a mess at 700. Lead is considered a "dead" metal, so stress relieving shouldn't be needed.

 

[Rtheurer]

Most bullet cores are pure lead or with a small amount of antimony. Lead melts at 622 degrees, so you would have a mess at 700. Lead is considered a "dead" metal, so stress relieving shouldn't be needed.

I believe they are discussing the Copper jacket and not the lead being stress relieved. Might be wrong however...

 

[Tim Singleton]

I believe they are discussing the Copper jacket and not the lead being stress relieved. Might be wrong however...

Yes, they are talking about the jackets
@geo.ulrich may see this and give more info about this

 

[RGRobinett]

Yes, they are talking about the jackets
@geo.ulrich may see this and give more info about this

When I began drawing back the jackets to relieve some of the work-hardening, George, provided GREAT advice, which has worked flawlessly - DO NOT exceed 500* F. You do NOT want/need DEAD SOFT!!
I use a 'mickey-mouse' knife makers oven, with [argon] purge, but no vacuum , which would be better, but pretty pricey.

A kitchen oven, could work pretty well, you'd just need to regulate the heat - the [kitchen] oven may do that well enough. My oven is programmable for all sorts of heating/cooling/purging facets (a LOT of overkill): the program I use for jacket draw-back, takes the temp up incrementally (need to match rate to purge to get a decent purge), to 475* F and holds it there for two [arbitrary] hours, then shuts off. I do not open the oven door until the temp drops back below 100*F, at which point, the temp is well below where rapid oxidation occurs.

This temp. will assure a [desirable] granular structure change , thus useful draw-back of work-hardening: a little residual resistance to 'working' is desirable . . .

Without purge, you'll have to remove the oxidation - but that's pretty easy. Even when the argon purge 'mostly works', a citric acid bath is still needed. So you don't have to back-track, here's the link again. < https://bibullets.com/bullet-making/ >

Note: "dead-soft" doesn't occur until the temp exceeds 650* F, but again, you don''t want to go there!
RG

 

[WIB3]

When I began drawing back the jackets to relieve some of the work-hardening, George, provided GREAT advice, which has worked flawlessly - DO NOT exceed 500* F. You do NOT want/need DEAD SOFT!!
I use a 'mickey-mouse' knife makers oven, with [argon] purge, but no vacuum , which would be better, but pretty pricey.

A kitchen oven, could work pretty well, you'd just need to regulate the heat - the oven my well do that well enough. My oven is programmable for all sorts of heating/cooling/purging facets (a LOT of overkill): the program I use for jacket draw-back, takes the temp up incrementally (need to match rate to purge to get a decent purge), to 475* F and holds it there for two [arbitrary] hours, then shuts off. I do not open the oven door until the temp drops back below 100*F, at which point, the temp is well below where rapid oxidation occurs.

This temp. will assure a [desirable] granular structure change , thus useful draw-back of work-hardening: a little residual resistance to 'working' is desirable . . .

Without purge, you'll have to remove the oxidation - but that's pretty easy. Even when the argon purge 'mostly works', a citric acid bath is still needed. So you don't have to back-track, here's the link again. < https://bibullets.com/bullet-making/ >

Note: "dead-soft" doesn't occur until the temp exceeds 650* F, but again, you don''t want to go there!
RG

Thank you very much RG for that information.

 

[Tim Singleton]

@RGRobinett
the Hines 790 and 820 jackets I have been using for a while seem a little softer than J4
Are they drawn back by Hines?

 

[WayneShaw]

I am curious as to weather the cores can be stressed relieved at home in the oven prior to core seating.

This is what I commented on, just sayin......

 

[D Coots]

Draw back an already good jacket....perfect

Later
Dave

 

[RGRobinett]

@RGRobinett
the Hines 790 and 820 jackets I have been using for a while seem a little softer than J4
Are they drawn back by Hines?

I do not know what Hines does, but believe that they do.

Several years ago, I got a bunch of Hines [.705"] .224 Jackets which 'folded' at an incredible % - 20-30 per 100!! I had bought them through Bart Sauter, and had just begun using that LOT, when he called, wondering if I had begun using them - proactive service there- and instructed me to return them, which, except for one case (10K), I did.

That case, I drew back on my own, which resulted in only a slight reduction of the 'folding' (the type which breaks from the mouth, and results in the jacket wrapping around itself), but still not good. Hines supposedly re-did the draw back and returned the jackets: ZERO improvement. Those jackets were 'saved' via obtaining a pinch-trim die and re-trimming, which COMPLETELY eliminated the 'folding', and made almost 10K GREAT 47 Gr. FB . . .

I'm straying from the point: for all of the jackets I've used, defects have been rare. I would not draw either Hines, or, Sierra, both of which, I believe, are drawn back as part of the process. Regarding J4, usually, I draw back only the long-for-caliber/high BC bullet jackets: if a batch of the point-blank lengths want's to 'mini-fold' I will draw them back - which may, or may not improve the situation. Oh - I consider more than 2-3 'folds' per 1K excessive. RG

 

[geo.ulrich]

Randy, After reading your last post I'm not sure you had a material issue but sounds more like an out of square pinch trim which will give nose folds ......

 

[AlNyhus]

IThose jackets were 'saved' via obtaining a pinch-trim die and re-trimming, which COMPLETELY eliminated the 'folding', and made almost 10K GREAT 47 Gr. FB . . .

I can attest to how great those 47's are.

 

[RGRobinett]

Randy, After reading your last post I'm not sure you had a material issue but sounds more like an out of square pinch trim which will give nose folds ......

George, I agree - and believe that, when the mini folds and their larger siblings occur during point forming, the pinch-trimming (non uniform/square), regardless of manufacturer, is the usual suspect . RG