How long to you allow freshly cast bullets to cool before sizing

[dankathytc]

I normally allow 48 to 72 hours for hardening before sizing and lubing. I will normally size and lube sound 200, and put the remainder in a jar properly labeled, until I need them. Curious about the general consensus.

[tazman]

I only cast handgun boolits currently. I water quench from the mold blocks. I try to get the sizing and lube done inside 24 hours since the boolits will get very hard to size if I wait.
If for some reason I have to wait longer, I run them through a Lee push through sizer before running them through my lubrisizer.
The boolits still harden quite well even if sized before they reach full hardness.
I can't speak for how well this system might work for rifle boolits.

[huntinlever]

I water quench, then dry them in the oven, and push the .461" as-cast through the .460" Lee push-through sizer, which also seats the gas checks. Less particular about when I lube them as I use the Lubrisizer to lube only. I let them rest at least a few days before I use them.

[Bazoo]

I don’t have any set times. I most often wait a few weeks or more.

[dankathytc]

TAZMAN, I cast only handgun bullets so far, from .357 up to .475. I water quench virtually all of my casts. I think I am correct in saying the hardening from quenching has more to do with antimony content? Most of my stuff is close to Lyman #2, or a little softer. Right now I am awaiting my first PID which should arrive tomorrow. Member Hatch, was kind enough to make for me. I can’t wait to learn it and test my alloys.

[243winxb]

Air cooled. Size any time.
Water cooled, wait 2 weeks to fully harden. Size anytime.

[JimB..]

Why wait to harden and make more work? Do exterior dimensions change as the alloy crystalizes?

[huntinlever]

I find if I wait any time at all they've hardened so much that sizing can be pretty tough.

[35 Rem]

I have no set waiting time. It might be the same day or years after casting.

[Winger Ed.]

I have no set waiting time. It might be the same day or years after casting.


Me too.
But I usually get to 'em in 2-4 weeks.

[fredj338]

Sooner is better with harder alloys. I water drop out of the PC oven, so try to get them sized in 2-3 days.

[rintinglen]

I try to size them as soon as possible after casting. They can age up and make sizing difficult, and If I want them hard, I'll heat treat them in the oven after sizing and installing gas checks.

[megasupermagnum]

The only reason to wait is if you happen to have an alloy that grows a lot with age, mainly antimony heavy alloys. I don't use such alloys. I've cast a bullet, sized, loaded, and shot it within 20 minutes before. It's pretty regular I cast and shoot my muzzleloader bullets the same day.

[deltaenterprizes]

I size and lube as soon as they get cool enough to handle!

[dtknowles]

I normally allow 48 to 72 hours for hardening before sizing and lubing. I will normally size and lube sound 200, and put the remainder in a jar properly labeled, until I need them. Curious about the general consensus.

Why wait, sizing will not stop the hardening and hardening will only make the sizing harder. Hardening is far from complete after 72 hours. Years later the hardening reverses and they start getting softer.

[GregLaROCHE]

I water quench most of the time. I don’t size right away only because I’m not loading them right after. I size what I will be loading just before. I bought a Rockchucker that I use only for sizing. Never any problems sizing, even after PCing.

[pworley1]

If I air cool, about 2 days. If I water quench, The next day.

[kevin c]

The fact that I bake my bullets twice during the HiTek coating process means I probably lose some of the hardness I might gain by aging my air cooled casts, I use an effective lube, only size down 0.001” and have an undemanding application for what I produce, so I don’t worry about the timing.

[Sig]

With WQ, I try to size the same day. It really depends on how much I need to size down. If only .001" it doesn't matter. If .003 I need to size the same day with my Star or I risk putting to much force on it.

[charlie b]

Qualifier, I rarely cast more than 200 or 300 at a time.

Normally I do the first size same day. Then PC is done the next day and finish sizing is done that same day.

If I quenched then I'd size them same day just so they do not get too hard.

When I store bullets they are ready to reload. I don't keep batches of unfinished bullets lying around.

[barrabruce]

I cast some tapered pb bullets and sometimes I drop them on the cloth then cast another.
I pick up the last bullet with tweezers and place hot bullet in lube tin then rest on base to harden.
Knock off the sprue drop bullet, cast another till I have as many as I need to load and shoot.
Save the rest till when ever I need them.

I think I’m saving labour and resources that way.

I do lube when hot and size and load some others as well and shoot usually the next morning.
If not I put into a pistol case holder to be loaded as I’m shooting the next day.
Ha
Sometimes I’m a bit casual like that and it’s good to have some spares handy kicking around.

[Larry Gibson]

With binary lead/tin alloys I will size and lube as soon as they are cool. Rifle or handgun doesn't matter.

Low antimony content [< 2.5%] ternary alloy handgun bullets I let sit 72 hours before sizing and lubing.

Ternary alloyed bullets, rifle or handgun, with > 2.5% antimony I let sit 10 - 14 days before sizing and lubing.

Water Quenched ternary alloyed bullets, rifle or handgun, I let sit at least 24 hours but most often 48 hours before sizing and lubing. I have sized and lubed, load and shot WQ'd handgun bullets on the same day w/o any noticeable adverse effect.

[JSnover]

I cast some tapered pb bullets and sometimes I drop them on the cloth then cast another.
I pick up the last bullet with tweezers and place hot bullet in lube tin then rest on base to harden.
Knock off the sprue drop bullet, cast another till I have as many as I need to load and shoot.
Save the rest till when ever I need them.

I think I’m saving labour and resources that way.

I do lube when hot and size and load some others as well and shoot usually the next morning.
If not I put into a pistol case holder to be loaded as I’m shooting the next day.
Ha
Sometimes I’m a bit casual like that and it’s good to have some spares handy kicking around.

I can't even express how much I love that idea!

[huntinlever]

With binary lead/tin alloys I will size and lube as soon as they are cool. Rifle or handgun doesn't matter.

Low antimony content [< 2.5%] ternary alloy handgun bullets I let sit 72 hours before sizing and lubing.

Ternary alloyed bullets, rifle or handgun, with > 2.5% antimony I let sit 10 - 14 days before sizing and lubing.

Water Quenched ternary alloyed bullets, rifle or handgun, I let sit at least 24 hours but most often 48 hours before sizing and lubing. I have sized and lubed, load and shot WQ'd handgun bullets on the same day w/o any noticeable adverse effect.

Larry what's the metallurgy behind letting ternary alloys sit before sizing? My experience is that it takes a lot more force to size if I wait, so I've been concerned about damaging the push-through sizer if I wait too long. But I'm curious on the science behind your waiting with the ternary alloys.

[megasupermagnum]

Larry what's the metallurgy behind letting ternary alloys sit before sizing? My experience is that it takes a lot more force to size if I wait, so I've been concerned about damaging the push-through sizer if I wait too long. But I'm curious on the science behind your waiting with the ternary alloys.

As a general rule, the higher the antimony, the more they grow with age. By waiting you negate the majority of the problem. In your case the cure is lube. You should be lubing or coating before sizing. If it's lubricated, it's easy to size even a 25bhn bullet .003" down. Unlubed is always an issue.

[huntinlever]

As a general rule, the higher the antimony, the more they grow with age. By waiting you negate the majority of the problem. In your case the cure is lube. You should be lubing or coating before sizing. If it's lubricated, it's easy to size even a 25bhn bullet .003" down. Unlubed is always an issue.

Thanks. I actually roll the bullets on a RCBS pad with RCBS lube, before sizing/gc'ing them through the Lee. Maybe it's just confirmation bias. I'll have to try some again on my next run, comparing new with aged.

So, you're saying the crystals expand relative to the antimony content? In other words, if you want to size to 0.460, if you size before waiting, your bullets will actually grow and you won't end up with 0.460, but something larger? Interesting, thanks. Not sure if there's a linear relationship between antimony and expansion rate or extent, but I currently cast Pb:No. 2 at 2:1, so I'm getting 1.67% tin and antimony, 96.6% lead.

[Larry Gibson]

The science of the metallurgy is best found in the article "The metallurgy of Molten Lead Alloys" by Dennis Marshall, Lyman Cast Bullet Handbook #3 and "The Metallurgy of Cast Bullets" by Robert J. Block in Lyman's Cast Bullet Handbook #4. They're pretty technical and, perhaps, a bit dry but the "science" information is there. The bullets will reach close to their maximum hardness in the times I mentioned based on actual daily BHN testing over a 30 day period. Others have also conducted such tests with similar results.

The short answer is that sizing the bullet prior to it achieving its maximum hardness work softens the sized area and stops, or lessons to a great degree, the hardening process. I try not to use alloys and sizings that do not require excessive force to size the cast bullets. I mix the alloys to achieve the hardness level they should. Sizing before they reach that hardness defeats the purpose of mixing the alloy. Granted with many cast bullets I shoot, especially some handgun and plinker cast bullets, the alloy mix isn't specific and the hardness doesn't matter. However, in many applications of cast bullet use, maintaining the expected hardness does matter.

A ternary alloy that is hardened to a BHN of 30+ is still exponentially much softer than a steel push through sizer. I seriously doubt you will damage the sizer. For example, I have sized .325 8mm bullets down to .314 in one pass through a Lee sizer w/o any problems. I always adjust the sizer in the press so the maximum linkage leverage is achieved. A little adjustment can make a lot of difference in sizing effort.

If sizing the bullets while still "soft" before they harden works for you and you are getting the performance you want then by all means continue. My original post was just stating what I've learned to do over the years. It was not intended as a "you must do this". Sorry if I was misunderstood.

[tazman]

TAZMAN, I cast only handgun bullets so far, from .357 up to .475. I water quench virtually all of my casts. I think I am correct in saying the hardening from quenching has more to do with antimony content? Most of my stuff is close to Lyman #2, or a little softer. Right now I am awaiting my first PID which should arrive tomorrow. Member Hatch, was kind enough to make for me. I can’t wait to learn it and test my alloys.

Others have given good information on how the various alloys effect boolit hardness. I know it takes a few days for the boolits to harden. After a couple of days, they will harden enough that using my Lyman sizer gets difficult to the point of damaging the sizer, hence the use of a good press and push through die.
I cast for 38/357, 9mm, 40 cal, and 45ACP with a variety of boolit designs. I use range scrap. If a certain batch seems to be running a little soft, I will drop an ingot of Linotype into the mix to "sweeten" it.
Most of my boolits end up in the neighborhood of 14-18 bhn.
I use a Lyman lubrisizer and use White Label NRA 50/50 for lube. It works well for me. I just don't have leading issues with this system.

All of this is very unscientific but serves my purposes quite well. I have tried harder and softer alloys and have seen no marked differences in accuracy. I am not a competition match grade shooter. My ammunition still shoots more accurately than I can.
I have done some testing from a bench with mounted optics so I have a pretty good idea what the ammo is capable of from my handguns. The weakest link is my skill as a shooter. Always will be. I am still working on it.

[huntinlever]

The science of the metallurgy is best found in the article "The metallurgy of Molten Lead Alloys" by Dennis Marshall, Lyman Cast Bullet Handbook #3 and "The Metallurgy of Cast Bullets" by Robert J. Block in Lyman's Cast Bullet Handbook #4. They're pretty technical and, perhaps, a bit dry but the "science" information is there. The bullets will reach close to their maximum hardness in the times I mentioned based on actual daily BHN testing over a 30 day period. Others have also conducted such tests with similar results.

The short answer is that sizing the bullet prior to it achieving its maximum hardness work softens the sized area and stops, or lessons to a great degree, the hardening process. I try not to use alloys and sizings that do not require excessive force to size the cast bullets. A ternary alloy that is hardened to a BHN of 30+ is still exponentially much softer than a steel push through sizer. I seriously doubt you will damage the sizer. For example, I have sized .325 8mm bullets down to .314 in one pass through a Lee sizer w/o any problems.

If sizing before the bullets harden works for you and you are getting the performance you want then by all means continue. My original post was just stating what I've learned to do over the years.

Crossed in the mail. OK, thanks Larry. Seems to work as it's all I've done and I develop loads around it, but it will be good to try your indications.

As to work-softening the bullets, I'd read that only the surface is work-softened and so this does little to the bullet as a whole, given aging after sizing. If I understand you correctly, this is erroneous, right?

[Larry Gibson]

Crossed in the mail. OK, thanks Larry. Seems to work as it's all I've done and I develop loads around it, but it will be good to try your indications.

As to work-softening the bullets, I'd read that only the surface is work-softened and so this does little to the bullet as a whole, given aging after sizing. If I understand you correctly, this is erroneous, right?

That's correct. But we must realize it's the surface of the bullet that takes to the rifling. In many cases that is the most important consideration.

[huntinlever]

That's correct. But we must realize it's the surface of the bullet that takes to the rifling. In many cases that is the most important consideration.

OK. Thanks Larry. I'll change up and see where I get. (At 1.67% antimony, I'll give it 72 hours as you indicate).

[Outpost75]

I don't size revolver bullets. I cast in 50 pound heat lots and bulk lube with 45-45-10. Bullets are loaded as-cast and unsized. Last die station on Star machine is Redding Profile crimp.

[georgerkahn]

I normally allow 48 to 72 hours for hardening before sizing and lubing. I will normally size and lube sound 200, and put the remainder in a jar properly labeled, until I need them. Curious about the general consensus.

I'm kind of a "session" guy. To wit, I'll gather lead, fluxes, moulds, etc. and do a "casting session" -- hopefully dropping a bit more than my thought for "need". The next session -- hopefully within a day or two -- is when I cull the ones with defects, and either size and lub them -- or, if say, I need :( :( changes lub's in lub-sizer as well as dies -- I generally hopefully get all ready -- to perform this task in a third session. I'm extremely UNtalented in making the lub and die switches if needed -- hence I practice this as a dedicated session.
geo
geo

[megasupermagnum]

Thanks. I actually roll the bullets on a RCBS pad with RCBS lube, before sizing/gc'ing them through the Lee. Maybe it's just confirmation bias. I'll have to try some again on my next run, comparing new with aged.

So, you're saying the crystals expand relative to the antimony content? In other words, if you want to size to 0.460, if you size before waiting, your bullets will actually grow and you won't end up with 0.460, but something larger? Interesting, thanks. Not sure if there's a linear relationship between antimony and expansion rate or extent, but I currently cast Pb:No. 2 at 2:1, so I'm getting 1.67% tin and antimony, 96.6% lead.

You are using what I consider a low antimony alloy, plus it's balanced with tin which has its own benefits. When I talk high, especially unbalanced, I'm mainly looking at hardball alloy which is 92/2/6 lead, tin, antimony. What can happen is if you size that bullet within an hour, it would be no huge surprise to find them .001" larger in say a month. I've not seen much more than that, but I have seen reports up to .003" growth. I've never tried an alloy with copper, but apparently those can grow even more. I do not understand the science on why it happens.

Larry brings up another point that is valid, although I personally don't worry about it. Maybe if you size early you are keeping the surface from fully hardening, maybe not. You have to size the bullet at some point, you are going to be working that lead at some point no matter what. The only true cure is to size first, and then oven heat treat bullets. It is only my opinion, but when I'm pushing the limits of a bullet the limiting factor does not seem to be the bullet surface based on recovered bullets. I almost universally use gas check bullets when pushing the limits, so seal is not a factor. Instead what I find usually is deformation of the bullet. Often the lube groove or crimp grooves will start to collapse. Sometimes the bullet nose will deform, which some call slump. When you size a bullet will not effect this. For most lighter target shooting loads, bullet hardness is not a factor to worry about at all.

[huntinlever]

You are using what I consider a low antimony alloy, plus it's balanced with tin which has its own benefits. When I talk high, especially unbalanced, I'm mainly looking at hardball alloy which is 92/2/6 lead, tin, antimony. What can happen is if you size that bullet within an hour, it would be no huge surprise to find them .001" larger in say a month. I've not seen much more than that, but I have seen reports up to .003" growth. I've never tried an alloy with copper, but apparently those can grow even more. I do not understand the science on why it happens.

Larry brings up another point that is valid, although I personally don't worry about it. Maybe if you size early you are keeping the surface from fully hardening, maybe not. You have to size the bullet at some point, you are going to be working that lead at some point no matter what. The only true cure is to size first, and then oven heat treat bullets. It is only my opinion, but when I'm pushing the limits of a bullet the limiting factor does not seem to be the bullet surface based on recovered bullets. I almost universally use gas check bullets when pushing the limits, so seal is not a factor. Instead what I find usually is deformation of the bullet. Often the lube groove or crimp grooves will start to collapse. Sometimes the bullet nose will deform, which some call slump. When you size a bullet will not effect this. For most lighter target shooting loads, bullet hardness is not a factor to worry about at all.

Fantastic, thanks. I do recall reading somewhere, can't recall where, on the benefits of balanced tin-antimony, but I can't recall why.
So ever since, I've tried to balance the two out. While I have recently loaded hotter loads for the 46-405VG from Accurate, just to do some range evaluation on hotter 5744 and 4198, nothing approaching the 425 Q from Tom I pushed to 1700+ fps. I also gc everything, so probably worrying too much about something that doesn't matter.

Very informative, much appreciated.

[JonB_in_Glencoe]

I don't let this detail make me get wrapped around the axle.
Sometimes I run them through a lubesizer right after a casting session, sometimes I put them unsized boolits in a jar and set it on the shelf for 10 years. I can't see how it can matter.

Huntinlever and Larry mention work-softening while sizing...and I agree that is a valid consideration to search out molds that drop a boolit near the ideal size (within .001), which is especially important for Rifle boolits. Many of the rifle boolit molds I use, drop boolits that don't really get sized when pushed through a lubesize die, but more that it gets "trued up".

[TurnipEaterDown]

What can happen is if you size that bullet within an hour, it would be no huge surprise to find them .001" larger in say a month. I've not seen much more than that, but I have seen reports up to .003" growth. I've never tried an alloy with copper, but apparently those can grow even more. I do not understand the science on why it happens.

If I remember my Metallurgy from 30-ish years ago:
it is due to the intermetallic lattice structure gaining a stable alignment. The structure can be viewed in a simplified manner as a tinkertoy cube w/ the round connector discs (that you plug the rods into) being the actual atoms at the vertices of the cubic structure. In the case of a homogenous metal, all the corners (atoms) are the same size, and when solidified these atoms are equidistant from others. The energy in the atomic bonds are evenly distributed, and all is hunky dory and happy. The atoms just sit there.
In the case of alloying, the alloying element can be looked at as a contaminant. The atoms now are not all the same size, and the bonds do not have the same energy. So, the cube structures become distorted and have imbalance in the bond energies. This is also what makes something "harder", energy being bound in these structures unevenly. They are stressed.
There is some useful thought analogy here w/ cold working a metal. That process creates intermetallic lattice dislocations (bond breaking) that also has an effect on bond energy and makes it harder (no pun intended) to distort further.

Been a LONG time, and I haven't used this in my jobs hardly ever in the last 30 years, but I am pretty confident my memory is good on this. I really liked metallurgy when I learned it, and sometimes I think I should have done that for a job.
Wouldn't surprise me at all to find someone on here that has more pertinent experience on me than this and find them chime in.

[Bigslug]

Anywhere from as soon as they've assumed room temperature to weeks or years after the fact.

[Larry Gibson]

The above mentioned metallurgy is all found in;

"The science of the metallurgy is best found in the article "The metallurgy of Molten Lead Alloys" by Dennis Marshall, Lyman Cast Bullet Handbook #3 and "The Metallurgy of Cast Bullets" by Robert J. Block in Lyman's Cast Bullet Handbook #4. They're pretty technical and, perhaps, a bit dry but the "science" information is there."

[dtknowles]

.....A ternary alloy that is hardened to a BHN of 30+ is still exponentially much softer than a steel push through sizer. I seriously doubt you will damage the sizer. For example, I have sized .325 8mm bullets down to .314 in one pass through a Lee sizer w/o any problems. I always adjust the sizer in the press so the maximum linkage leverage is achieved. A little adjustment can make a lot of difference in sizing effort.....

I use a Lyman lubrisizer and there is no adjusting the linkage for more leverage. The linkage is also much weaker than the linkage on most reloading presses. I don't remember what I was doing but I broke one of the links on my lubrisizer and had to repair it.

Tim

[dtknowles]

I found this here https://www.totalmateria.com/page.aspx?ID=CheckArticle&site=ktn&NM=88#:~:text=In%20alloys%20of%20the%20lead-tin%20system%2C%20the%20initial,hardening%20by%20G uinier-Preston%20%28GP%29%20zones%20formed%20during%20agi ng.

Solution Treating and Aging
Adding sufficient quantities of antimony to produce hypoeutectic lead-antimony alloys can attain useful strengthening of lead. Small amounts of arsenic have particularly strong effects on the age-hardening response of such alloys, and solution treating and rapid quenching prior to aging enhance these effects.
Hardness Stability. For most of the two-year period, the solution-treated specimens were harder than the quench-east specimens. Other investigations have also shown that alloys cooled slowly after casting are always softer than quenched alloys. The alloys with 2 and 4% Sb harden comparatively slowly, and the alloy containing 6% Sb appears to undergo optimum hardening.

This might also be helpful
http://www.lasc.us/Fryxell_Book_Chapter_3_alloySelectionMetallurgy.ht m

[Larry Gibson]

Over the years of sizing, GCing and lubing thousands of cast bullets of various calibers and alloys I've broke 2 or 3 link pins on my four Lyman 450s. The metal was crystalized at the break. When they broke, I wasn't doing any forceful sizing. I simply replaced them with stainless bolts from Ace Hardware or Lowes. However, I have sized some bullets which were "hard" to size but I've used successively smaller H&I dies. I've never really sized "hard" bullets in one step.

I also have sized down some AC'd COWW + 2% tin .325 323470 & 323471s already lubed and GC'd down to .314 in one sizing. Never had a problem with that.

[243winxb]

Oven heat treating, water cooled bullets harden at different rates, depending on the % of antimony. 2%= 2 weeks. 6%= 24 hours. https://www.thehighroad.org/index.php?media/make-cast-bullets-harder-oven-heat-treating.4774/full

[dtknowles]

Over the years of sizing, GCing and lubing thousands of cast bullets of various calibers and alloys I've broke 2 or 3 link pins on my four Lyman 450s. The metal was crystalized at the break. When they broke, I wasn't doing any forceful sizing. I simply replaced them with stainless bolts from Ace Hardware or Lowes. However, I have sized some bullets which were "hard" to size but I've used successively smaller H&I dies. I've never really sized "hard" bullets in one step.

I also have sized down some AC'd COWW + 2% tin .325 323470 & 323471s already lubed and GC'd down to .314 in one sizing. Never had a problem with that.
I never had a pin break but I cracked the handle were the pin went through the strap. I don't remember what I was doing but I was certainly putting more force on the handle than I should have. I might have been swaging down jacketed bullets. I have done that successfully on pistol bullets but I might have tried something more extreme.
Tim

[marshall623]

I've always size my water quenched bullets as soon as they are dry or within a few hours , I can load them then but don't shoot them for 2 -3 weeks .Most of the time they go into a container. Air-cooled bullets go into a container and get sized as I need them . I cast most everything from COWW with 2% tin added . So far it works , I tried reading the metallurgy section fron Cast Book #4 but it was just a blur . I'll dig into it later

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