Sizing Question

[BABore]

This has to do with heat treated WW bullets. From what I've gleened in my long 8 months of casting is;

#1 If you water drop WW bullets you should check, size, and lube them right away.

#2 If you oven heat treat WW bullets you should size and check first, then run them back through the lube sizer, in a 0.001" oversized die, to lube them after heat treatment.

Now I have only used the second method because the first just goes against common sense. Whether water dropped or oven HT'd, once quenched, the bullets are 18-23 Bhn. After 1-2 weeks they will be 25-30 Bhn. If they can be softened by working them (sizing), it's going to happen with both methods of HT. Am I wrong here?

I am in the process of sending in some Saeco 0.460 dies to Stillwell for some honing. These will be for a 0.4780 sizing die. I plan to oven HT my bullets. Is it absolutely necessary to also get a 0.4790" die as well? If you buy into the sizing of water dropped bullets, what is the difference if I just run the oven HT'd bullets back through the same die again for lubing? At $23 for the die and $22 for honing, a cheap mind wants to know.

[felix]

#1 If you water drop WW bullets you should check, size, and lube them right away.

Answer: Only if they are short boolits. If they are long and somewhat oversize, then it is best to let them harden for a week before sizing. They won't size straight otherwise. This would not be the situation if we could PULL a boolit through a sizer, but that cannot be done because there is no good way to grab the boolit to pull it through anything. Point first sizing using the push method is next best, but still a long way from the truth.

#2 If you oven heat treat WW bullets you should size and check first, then run them back through the lube sizer, in a 0.001" oversized die, to lube them after heat treatment.

Answer: If the boolits have lots of antimony, which is SINGLE element which makes them grow in size, then you cannot get away with checking the boolits before oven-treating them without serious risk of their shanks cracking during rapid cooling. The cause is the expansion/contraction characteristics of antimony and copper. So size the boolits first, then oven-treat, followed by checking and sizing after the boolits are good and hard. Hard because you don't want to bend a long boolit during the installation of the check.

felix

[BABore]

This would be for straight WW's, so I would ass-u-me the antimony is 2-4%.


Answer: Only if they are short boolits. If they are long and somewhat oversize, then it is best to let them harden for a week before sizing. They won't size straight otherwise. This would not be the situation if we could PULL a boolit through a sizer, but that cannot be done because there is no good way to grab the boolit to pull it through anything. Point first sizing using the push method is next best, but still a long way from the truth.

The bullets in question will all be 0.8" plus in length and either 0.460 or 0.478 dia. Won't sizing them down a few thou after being fully hard destroy the HT?


So size the boolits first, then oven-treat, followed by checking and sizing after the boolits are good and hard. Hard because you don't want to bend a long boolit during the installation of the check.

Can I use the same size die or should it be a thousandths bigger?

This probably explains why my 480 bullets pop a few GC's off when I quench.

[Maven]

BABore, The water-drop then size v. size first, heat-treat and lube in a .001" die has been argued before. Dennis Marshall, a metallurgist by profession and a CB shooter by avocation, wrote about this in various CB handbooks by Lyman, the NRA and RCBS. He clearly demonstrated, with photographic evidence of changes in the microcrystalline structure of WW alloys, that sizing negatively affects the BHN of water-dropped CB's. Marshall's photos show that said "softening" isn't merely skin deep, but pervasive. He also showed that sized, then heat-treated CB's (WW's + 1% Sn) can exceed the BHN of linotype, 28-30 v. 22, respectively.

[cbrick]

I have been oven heat treating WW + tin for many years. My process has evolved due to articles by Dennis Marshall and others in Rifleman, Handloader etc and years of my own experiments.

I gave up water quenching (dropping from mould to water) several years ago because I could not get consistent results. I also stoped using my propane cook oven in favor of an electric convection oven. The difference here was incredible in getting a repeatable, predictable and consistent BHN. A known oven temp for one hour will result in a predictable BHN.

I always size and gas check and then heat treat. Heat treating does not change sized diameter and after many, many thousands of heat treated bullets I have never had a gas check come off but I don't use high antimony alloy. Once heat treated they are placed in a labeled box (date, BHN, Alloy, sized diameter) and when I need them I lube in a die .001" larger than sized diameter. A note on gas checking before heat treating: I have a machinist friend make a gas check sizer for me and size them for a perfect, flush, fully seated, flat check that doesn't need to be pushed on, just held in place while being crimped.

I have always heard that heat treated bullets age soften and a month ago I got the chance to test this. I found tucked away in the back of the loading bench a box of 7mm bullets labeled 30 BHN, Jan - 96. I tested them and they were 26-27 BHN. They did age soften but 3-4 BHN in ten years.

My testing includes bullets from 35 moulds in many calibers from .224" through 45. All of my sizing is done nose first through a Star lubrisizer. Lubing is done on either the Star or SAECO machine depending in the sizer die I have on hand.

Does sizing work soften the alloy? I have tested the BHN of bullets and then filed them down & re-tested the BHN. I get a very consistent 1 BHN less on the filed sample. Just a SWAG on my part but I tend to agree with Dennis Marshall that sizing will work soften the bullet through out. How much? I dunno but the result of the finished product is in the grouping and chronograph tesing. If your water quenched bullets are 18 BHN and then sized and they are 17 BHN and they work for your shooting requirements they are fine.

I have done a lot of testing to determine the effect of BHN changes on groups. BHN's within a given range don't seem to effect groups. Open up that range and groups open up, sometimes a lot. For example, my best 150 meter revolver groups are with 18 BHN bullets. groups are not effected by a range of 17-18 or 18-19 BHN. They are affected a lot with BHN ranges of 16-20 or more.

Rick

[slughammer]

I'm new to water dropping and heat treating, so perhaps a different perspective here.

First, depending on boolit construction, as much as .001 diameter difference may be noticed by sizing hard vs. soft from the same size die. Depends on boolit construction and spring back.

Second, does it really matter that they loose hardness when sized? How much hardness is lost when there is 20,000psi shoving it from a .311 throat into a .309 bore?

[felix]

Hardening and softening are both time dependent. You do not loose any significant hardness if you size your boolits, and load and shoot them that same day. ... felix

[Cayoot]

I think his main question here is the same one that has been bothering me for a while.

If the boolit is sized before heat treating, then after ht, they need to be lubed.

The question is this:

Is it necessary to get a sizer die (to apply the lube) .001 larger than the sizing die that was used b4 HT ? If the boolit was sized down b4 heat treating, shouldn't the boolit fit through the same sizing die (for lube application) with out being "worked softened" to any measurable degree?

Seems that this is what he is asking and it has also been on my mind...mainly because it is such a PITA to change sizing dies in my star!

Has anyone done any testing in this area?

Thanks in advance.

[felix]

Change dies only after letting the boolits sit for some time before final sizing. They will grow if there is enough antimony to make it happen. Otherwise, use same die, especially if the checks you are applying are soft (annealed). In other words, don't apply pressure to soft boolits. ... felix

[cbrick]

Cayoot,

It does work to use the same die to lube as it was sized in. It slightly shines the driving bands but, and it's a SWAG on my part, I doubt it would work soften the bullet enough to matter if at all.

Question for you Cayoot, do you have the Star die removal tool?? With it swaping dies in a Star is quick & easy.

Star instruction manual (http://www.magmaengr.com/pdf/StarSizerInstructions.pdf)

Rick

[Cayoot]

No, I don't have the tool. I bought my star off Evil Bay and only got the luber/sizer.

I have been wondering how the dies are changed. To be honest, it is such a PITA, but I love the Star so much, that I have actually been thinking about buying a few stars....one for each of the calibers that I shoot alot of.

[cbrick]

Check out the link above to Magma's PDF page. A few bucks for this tool is a lot cheaper than a new lubrisizer for each caliber.

Rick

[BABore]

Change dies only after letting the boolits sit for some time before final sizing. They will grow if there is enough antimony to make it happen. Otherwise, use same die, especially if the checks you are applying are soft (annealed). In other words, don't apply pressure to soft boolits. ... felix


Ahh, my question is finally answered. Thanks all.

[Cayoot]

OK Felix....thanks!
So as I understand it, as long as I'm going to lube soon after heat treating, I can use the same die as I used for the initial sizing eh?

Thankx Much!!!!


Change dies only after letting the boolits sit for some time before final sizing. They will grow if there is enough antimony to make it happen. Otherwise, use same die, especially if the checks you are applying are soft (annealed). In other words, don't apply pressure to soft boolits. ... felix

[Cayoot]

Thanks Cbrick! From your response, am I to understand that (given the correct tool) it is not hard to change the dies in a Star?


Check out the link above to Magma's PDF page. A few bucks for this tool is a lot cheaper than a new lubrisizer for each caliber.

Rick

[cbrick]

Under a minute to swap dies. Nothing like the right tool for the job. You can contact Magma via their contact form at:

Contact Magma (http://www.magmaengr.com/contactUs.php)

Or by phone at:

To Order, Voice 480.987.9008
Fax 480.987.0148

Rick

[Cayoot]

Thanks so much Rick....

As I'm at work (Shhhhh!!!!!) and my company has a lock out of any marketing, weapons or chatting websits, I cannot follow the link.

So I really appreciate the phone numbers!!!!

Now I'm gonna order that tool!!!! Under a minute!!! WOW!!! LIFE IS GOOD!!! [smilie=p:


Under a minute to swap dies. Nothing like the right tool for the job. You can contact Magma via their contact form at:

Contact Magma (http://www.magmaengr.com/contactUs.php)

Or by phone at:

To Order, Voice 480.987.9008
Fax 480.987.0148

Rick

[Springfield]

I change the dies on my Star all the time, less than a minute is accurate. I have a 2 piece top punch though, never have to use the threaded part of the changing tool.

[Lloyd Smale]

you may laugh but ill tell you how i change dies in mine. I heat the die chamber with a torch until the lube starts to melt and just push it out with my finger ive done it for over 10 years and never hurt a thing.

[Cayoot]

You're kidding.....that sounds too good to be true, clean the old lube out and change dies that quick? Do you have any cautions to add? Any hidden o-rings or anything else I need to watch for?


you may laugh but ill tell you how i change dies in mine. I heat the die chamber with a torch until the lube starts to melt and just push it out with my finger ive done it for over 10 years and never hurt a thing.