Annealing Jackets

[Tim Singleton]

@geo.ulrich @RGRobinett

would you guys tell us about annealing jackets.

your method to do this
if you do and why you do

Hines seem to work easier than j4 for me

 

[jimmymac]

You are in deep Tim. Good for you.

 

[dcali]

I would buy Sierras and not worry about it.

George annealed some Hines .30s for me once and it didn't do much - pretty much what you'd expect - they didn't stretch as much. (I was trying to sort out some issues with a finicky die at the time - it wasn't the jackets). Sierras have all been perfect. Even when made a year apart.

 

[jackieschmidt]

It’s he opposite for me.

when I first started making my 30’s, I tried both J-4 and Hines. The Hines took quite a bit more pressure in both the core seating and point up. I settled on the J-4.

when I was attempting to make a long range 6mm bullets, the Sierras were much easier to make than the J-4’s. I bought a small electric oven and heated the jackets for one hour at 450 degrees. It definitely softened them, and the color changed to a beautiful yellow gold.

I have some Sierra 1.140 and .950 length jackets if you are interested. It is just about impossible to get them from Sierra anymore.

 

[dcali]

I've heard different reports on the Hines jackets. Some say they're hard, some say they're not. The ones I got (1.400" .30s) seem more or less like Sierras, and were exceptionally consistent. I couldn't even measure the weight variation on my FX-120i. They also turned yellow when annealed.

I also have a small sample of Sierra 1.180"s that are an ugly orangey purple that I could not get to shoot. The same dies using Sierra 1.140" jackets produce excellent bullets. Not sure what was up with that. They didn't seem any harder or softer though. At least not by feel.

 

[Tim Singleton]

I have a lot of 6mm 790 J4 that are pretty hard compared to Hines and Sierra that I have
would like to soften them up a tad. i wondered if keeping a argon or nitrogen purge on them was a have to
how long and what temp to anneal at

 

[geo.ulrich]

Tim, I sent you a P.M.

 

[BartsBullets]

It’s he opposite for me.

when I first started making my 30’s, I tried both J-4 and Hines. The Hines took quite a bit more pressure in both the core seating and point up. I settled on the J-4.

when I was attempting to make a long range 6mm bullets, the Sierras were much easier to make than the J-4’s. I bought a small electric oven and heated the jackets for one hour at 450 degrees. It definitely softened them, and the color changed to a beautiful yellow gold.

I have some Sierra 1.140 and .950 length jackets if you are interested. It is just about impossible to get them from Sierra anymore.

A lot of people think the Hines are harder and They aren’t. Hines are cleaned and stripped of any oil. They almost feel crunchy if you pick up. So need more lube to seat cores.

 

[Tim Singleton]

Thanks George

450f for one hour seems to have done the trick

 

[Ken Melgaard]

so… how would one quantify the hardness (brindle) of the finished jackets, as we received them? They certainly don’t come with a certificate of conformity!
And this would depend on the gilding metal (C21000) 95% copper 5% zinc and from previous discussion R.G Robinette had some jackets tested and there are variations to this percentage of copper V’s zinc from, Sierra to Berger J4, l don’t remember Hinse being tested
Would there be away of testing them before & after annealing them, or just looking for a colour change and temperature and duration time @ 450 C temperature

 

[dcali]

so… how would one quantify the hardness (brindle) of the finished jackets, as we received them? They certainly don’t come with a certificate of conformity!
And this would depend on the gilding metal (C21000) 95% copper 5% zinc and from previous discussion R.G Robinette had some jackets tested and there are variations to this percentage of copper V’s zinc from, Sierra to Berger J4, l don’t remember Hinse being tested
Would there be away of testing them before & after annealing them, or just looking for a colour change and temperature and duration time @ 450 C temperature

I would not rely on color change. You'd need to test them if you want to quantify it.

This is for pure copper, so it's not something you can really rely on, but it should give a ballpark of the annealing affects.

https://apps.dtic.mil/sti/pdfs/AD0615926.pdf

You can get better info from the American Society of Materials Heat Treatment Guide, but you have to pay for it. They're about $25 each. I have the one for cartridge brass (30% zinc), which iw pretty interesting. I don't have one for other copper-zinc alloys, but I bet there is one.

What's interesting is that the one hour full annealing temperature is north of 700 degrees for these alloys with 1" rods. 450 will barely change them. But obviously, jackets are not 1" thick, which sill speed things up. Someone with experience making jackets would be able to tell you where they start, and where they end up as far as hardness goes (I have no idea, quantitatively).

Practically, what you're looking at is subtle things like the amount of lube required, how much stretch you get, how hard it is to form them, how easy it is to pop the jackets, etc. If 450 for an hour gets you where you want to be with these qualitative measures, that's all you need to know. It's more art than science in practice.

 

[Tim Singleton]

What matters to me is how they feel and work up in my die
Some lots of J4 have been hard to work with for me

 

[liseo]

Old topic, but I would like to know the opinion of those who have more experience than me.
I received a batch of jackets for 168 grain bullets, with a length of 1,200". I had a high percentage of folded tips.
Considering my experience producing bullets from 22 LR cases, where I observed that if I did not annealing after deriming, practically 50% formed the folded tip.
If I did annealing before point up, it decreased to practically 0%.
My question is whether any of you usually do annealing to solve it or if this technique does not apply to commercial jackets, which have a different alloy, and only works for 70/30 brass, normally used to produce cartridges.(cases)
***I don't know if I used the correct words, as English is not my native language.

 

[FNSafari]

It’s he opposite for me.

when I first started making my 30’s, I tried both J-4 and Hines. The Hines took quite a bit more pressure in both the core seating and point up. I settled on the J-4.

when I was attempting to make a long range 6mm bullets, the Sierras were much easier to make than the J-4’s. I bought a small electric oven and heated the jackets for one hour at 450 degrees. It definitely softened them, and the color changed to a beautiful yellow gold.

I have some Sierra 1.140 and .950 length jackets if you are interested. It is just about impossible to get them from Sierra anymore.

Which jackets made the most accurate bullets?

 

[Tim Singleton]

Per George’s instructions

Tim, Draw jackets back at 440-450 is where 90% will start to change. some need to go higher but at that point there not going to really be that great.. no need for purge system . allow oven to go to full temp then put them in a glass dish for one hour and pull out and air cool....

 

[Tim Singleton]

Boil in citric acid to clean afterwards

 

[Webster]

A lot of people think the Hines are harder and They aren’t. Hines are cleaned and stripped of any oil. They almost feel crunchy if you pick up. So need more lube to seat cores.

You shouldn't be able to do any annealing at 450F for 1 hr. Probably stress relieving is taking place. That's a big rabbit hole. If I was not retired I could do some actual hardness testing for you guys. It would be nice to have real numbers.

 

[mauser284]

First you need to add moon rocks to your oven.......

 

[Tim Singleton]

You shouldn't be able to do any annealing at 450F for 1 hr. Probably stress relieving is taking place. That's a big rabbit hole. If I was not retired I could do some actual hardness testing for you guys. It would be nice to have real numbers.

Annealing wasn't the right word to use, agreed.

Drawing back is the word George uses

Whatever word you want to use, heating hard J4 jackets at 450f for one hour does the trick