Oven Tempering v. Direct Quenching - anyone compare BHN?

[huntinlever]

Off for a couple weeks during a move. I've always just dropped bullets on casting into H2O and called it a day, though I speed up their drying by leaving them in the oven at about 150 for an hour or so.

I understand the principle for heat-treating in the oven then dumping into, say, ice-water. Because as you dump into the WQ bath, the water temp rises and you'll have bullets' hardening variances accordingly.

Try to limit as many steps between casting and shooting as possible, without compromising performance - where performance is defined as 45-70 cast bullet (405 grain, 1650 or so fps) dependability for all hunting conditions at c. 100 yards, nothing more.

In practice, anyone actually measure BHN differences between direct-quenched and oven-treated-quenched bullets? Or even just anecdotal experience? Significant differences, or unnecessary complication for a heavy piece of shoulder mortar?

[Bigslug]

Setting aside for the moment that you are burning brain cells taking competitive benchrest level pains for a practical level of field accuracy that can successfully met by smoothbore shotguns with Foster slugs and of terminal performance that can be met with a 5.56 NATO. . .

If the game is consistency / good lab technique, consider the following:

Obviously, straight drop from the mold and batch quenching from an oven tray MAY get you to the same place for BHN, BUT. . .

Oven tempering gets them all to the same temperature, and quenches them all at the same rate.

Dropping individually into a bucket will have you tempering flawed bullets that you'll ultimately cull for imperfections, and will get those same duds wet and needing to be thoroughly dried before you can safely melt them down again.

Selecting a harder alloy such as Lyman #2 that will meet your hardness and toughness requirements without the need for quenching eliminates the step entirely.

For this "performance" you're trying not to compromise, you need the accuracy to hit a 7" paper plate (which you had way back with the two loads you were comparing chrono numbers on), and the mass + velocity-to-whitetail ratio of your proposed .45-70 is roughly equivalent to a jumbo blacksmith's anvil dropped from 30 feet onto a field mouse.

Truly, you're making this far too complicated. I'm here for your mental health.

[huntinlever]

You'll have to speak more plainly. I'm not catching your drift.

61, afraid I've been dying of terminal overthinking oh, about 61 years, but point taken.

So, just smelted 50# for 3-3-94. I'm probably misusing the word "oven tempering." I'd thought that was the process to bring bullets up to the same temp, then quench in an ice water bath so they all hold roughly the same hardness, your first description.

I'd love to forego water quenching altogether. I've only read anecdotally of bullet deformation when casting and dropping on something like a towel on a tray. Probably like much else a non-issue. So - as simple as that, drop on some sort of cloth and allow to rest? At 3-3-94, how long before sizing (sketchy memory - vague recollection of Larry Gibson, perhaps yourself, talking about waiting period before sizing, due to shrink back?)? Then how long resting before loading and shooting?

[243winxb]

Use an alloy of 2%-Tin,6%-Antimony, and 92%-Lead. Cast & drop bullets on towel to cool. Soon as cool, size/lube. Done.

Oven heat treating, water cooled only needs 2% antimony to fully harden in 2 weeks. A higher persent of antimony makes harding faster.

Accuracy is better with oven heat treating. Dropping from mold to water, not as good.

[Bigslug]

Line the lid of a cardboard paper-ream or file box with your oldest, rattiest bath towel. All the receptacle you need.

As long as you've got the unquenched bullets, shoot some as-is. With the gas checks, your 94/3/3 may be OK. PROBABLY better hardened up, but you are somewhat on the line. I'm a big fan of discerning and eliminating the unnecessary.

[JonB_in_Glencoe]

As to difference in measured BHN, It's about a horse a piece...give or take a horse.

[charlie b]

My last years of hunting were with muzzleloaders, .50 and .45 cal slugs (450-300gn). Out to about 200 yd they penetrated mule deer and elk nicely. No HP's, just flat nose soft lead.

[Wheelguns 1961]

Maybe this will help you out. I did a little test. Nothing scientific. I cast some 45 cal bullets, and let them air cool. When I powdercoated them, I puposely left a few uncoated. So they all go in the oven at 400 degrees for 25 minutes. When they came out, I water quenched half of the uncoated ones, and let the other half air cool. These were all from the same alloy, 50/50 +2%. About an hour later, I checked the hardness. The air cooled bullets were about 10bhn, and the water dropped ones were about 14bhn. A week later, the air cooled ones were about 10 1/2bhn, while the water dropped ones were about 15. Two weeks later the air cooled bullets were still 10 1/2bhn, and the water dropped bullets were 15 1/2 bhn.

I know this doesn’t prove anything. It was just a little test, and I was only doing it to satisfy my own curiosity. If I water quench bullets, I size them sooner, rather than later. For my own use, in my guns, I use all powder coated, air cooled bullets, but I am not shooting anything with high velocity.

[huntinlever]

Maybe this will help you out. I did a little test. Nothing scientific. I cast some 45 cal bullets, and let them air cool. When I powdercoated them, I puposely left a few uncoated. So they all go in the oven at 400 degrees for 25 minutes. When they came out, I water quenched half of the uncoated ones, and let the other half air cool. These were all from the same alloy, 50/50 +2%. About an hour later, I checked the hardness. The air cooled bullets were about 10bhn, and the water dropped ones were about 14bhn. A week later, the air cooled ones were about 10 1/2bhn, while the water dropped ones were about 15. Two weeks later the air cooled bullets were still 10 1/2bhn, and the water dropped bullets were 15 1/2 bhn.

I know this doesn’t prove anything. It was just a little test, and I was only doing it to satisfy my own curiosity. If I water quench bullets, I size them sooner, rather than later. For my own use, in my guns, I use all powder coated, air cooled bullets, but I am not shooting anything with high velocity.

Thanks for the info, yes, that's really helpful.

A general thanks and apologies for the delay guys, been moving and this old bod' has taken the beating it earned - lessons never learned, to get rid of more stuff as my sinews turn to jerky, lol. Downsized "bench" and hoping to cast later this afternoon.

Thanks again.

[TD1886]

You're fine with an alloy that will harden by just water quenching them. Oven heat treating is just another hassle.

[huntinlever]

I hate hassle too, TD. I'm going to try just a bit and see if I notice anything worth making the extra step. Though as Bigslug says, I'm probably putting way too much effort into what amounts to shoulder artillery within 125 yards.

Question guys - I plan on casting, air cooling, then pushing through Lee sizer to size and seat gas checks. I usually use RCBS lube-pad lube before pushing through the lee sizer.

Here, I'd be sizing, gas check seating, oven treating at about 420F, then batch-water quenching.

-How many use the Lee push through without any lube? REALLY want to avoid having to wash off the sized and gc'ed bullets prior to oven heating, unless I'll compromise the Lee.
-any issues with the copper gas checks at 420F (can't remember the melting point, but I think this is a non-issue as the m.p. is much higher)?

[huntinlever]

Use an alloy of 2%-Tin,6%-Antimony, and 92%-Lead. Cast & drop bullets on towel to cool. Soon as cool, size/lube. Done.

Oven heat treating, water cooled only needs 2% antimony to fully harden in 2 weeks. A higher persent of antimony makes harding faster.

Accuracy is better with oven heat treating. Dropping from mold to water, not as good.

If I do go this way (use the RCBS lube prior to initial sizing through the Lee Push-Through; not unlubed), a few questions to you or anyone:

1I presume you are seating gas checks when you size, correct?

What do you use to get the RCBS cleaned off the bullets?

To confirm, the copper gas checks can withstand the oven treatment of say 420F?

Finally, I find that sometimes the gas checks aren't seated too tightly. On, with some "snap," but not like they're all bonded or anything. I can see many getting knocked off when dropping into the water. If so, I'd have to use the sizer again, just to seat a gas check. Anyone who does this method, do you have issues with losing gas checks?

[243winxb]

Apply lube, Lee size, wash lube off in hot water. Oven heat treat, water cool. Let dry. Add GC, lube, size 2nd time. Dry.

My rifle bullets got sized, with GC in Lyman 450 lube/sizer. The bullet hardness is same to center of bullets.

I do this about 99% of the time-

Use an alloy of 2%-Tin,6%-Antimony, and 92%-Lead. Cast & drop bullets on towel to cool. Soon as cool, size/lube. Done.

[indian joe]

Setting aside for the moment that you are burning brain cells taking competitive benchrest level pains for a practical level of field accuracy that can successfully met by smoothbore shotguns with Foster slugs and of terminal performance that can be met with a 5.56 NATO. . .

If the game is consistency / good lab technique, consider the following:

Obviously, straight drop from the mold and batch quenching from an oven tray MAY get you to the same place for BHN, BUT. . .

Oven tempering gets them all to the same temperature, and quenches them all at the same rate.

Dropping individually into a bucket will have you tempering flawed bullets that you'll ultimately cull for imperfections, and will get those same duds wet and needing to be thoroughly dried before you can safely melt them down again.

Selecting a harder alloy such as Lyman #2 that will meet your hardness and toughness requirements without the need for quenching eliminates the step entirely.

For this "performance" you're trying not to compromise, you need the accuracy to hit a 7" paper plate (which you had way back with the two loads you were comparing chrono numbers on), and the mass + velocity-to-whitetail ratio of your proposed .45-70 is roughly equivalent to a jumbo blacksmith's anvil dropped from 30 feet onto a field mouse.

Truly, you're making this far too complicated. I'm here for your mental health.

This!!!

[indian joe]

Apply lube, Lee size, wash lube off in hot water. Oven heat treat, water cool. Let dry. Add GC, lube, size 2nd time. Dry.

My rifle bullets got sized, with GC in Lyman 450 lube/sizer. The bullet hardness is same to center of bullets.

I do this about 99% of the time-

heres a better plan
drop boolit from mold onto folded towel
put the duds back in the melt as you go
pan lube
size
load
go shoot
come home grinning put bambi in freezer
sit on verandah and drink beer while ole mate is still fussin around heat treating boolits (after he recovered from the mini explosion generated from getting water mixed up in the melt at the casting bench)

[huntinlever]

Well, tried it. First, appreciably better casting with this new alloy - 94-3-3. Found a good avg. of 393 grains and keeping any 392.0-293.9 grain as cast.

Not sure I want to commit to the process, in the spirit of "what are you (over)thinking?" At the very least I should just cast and quench this new alloy as I've always done with past alloys and see what happens at the range. Not sure I'd feel comfortable just air-cooling and shooting them, as I'm shooting a pretty stiff load (but you guys I'm sure will have your thoughts on this).

One thing I'd ask - so, I cast, air-cooled, lubed with RCBS case lube, sized and gas-checked, washed with hot soap and water, oven-heated at 425 x 1 hour, quenched in ice water, dried. In other words, the copper gas checks were heated along with the bullets to 425. I noticed after quenching that they (gas checks) had changed color somewhat. Paler, maybe. Have these been compromised?

Thinking of just tossing all (52 only) back into the pot, and going back to "the old ways." - cast and quench, dry, size and gas check, lube in 0.001+ lubrizer.

[Dusty Bannister]

The gas checks have not been compromised, they have been annealed and will be a little softer so will not have as much resistance when the bullet is lubed and sized.

[huntinlever]

The gas checks have not been compromised, they have been annealed and will be a little softer so will not have as much resistance when the bullet is lubed and sized.

OK thanks, Dusty. I'd thought I'd be OK because I only use the Lubrisizer for lubing, as it's 0.461 (I size to 0.460).

[huntinlever]

Setting aside for the moment that you are burning brain cells taking competitive benchrest level pains for a practical level of field accuracy that can successfully met by smoothbore shotguns with Foster slugs and of terminal performance that can be met with a 5.56 NATO. . .

To say it plainly, with this alloy at a higher pressure load, you'd say, cast, quench, size/gas check, lube and load - is that right? Ignore the variability given changing water temp, cast/drop rate, etc.?

[Dusty Bannister]

I would say that the change in water temp for the quench will be the most predictable variable involved in this method because the temperature range is so small. (maybe 50 degrees). The alloy temp will probably vary a lot more than that, and below some point the hardening will not be as affective. That temp is probably in the notes on the LASC site. At some point, the practical hardness of the alloy will no longer be a factor as the pressure will not obdurate the bullet anyway.