Heat-treat got my boolits REALLY hard

[kelbro]

Finally got a chance to cast some with my RD 311-165 6-banger yesterday (what a great mold!) for my '94 30-30. Used WW with about 2% Sn. Boolits came out great and had very few rejects. The range of weights was 168.7 - 171.4 for over 100 bullets.

I put them in the toaster oven @ 430° for an hour. Took them out and tested them an hour later. They all measured around 28BHN and are a very dark gray color. I have HT'd 44 bullets before and don't recall them getting that hard or changing to that dark of a color.

I normally use #2 for hunting boolits but the WW/2%Sn was what was in the pot at the time.

Is that BHN about what you would expect from that alloy and HT?

Since this is for my 30-30 and they are hunting boolits, should I anneal the tips?

Haven't shot them yet. I will tomorrow.

[Rocky Raab]

I think you should have left well enough alone, quite frankly. Your original mix, air-cooled, would have been perfect in my book.

[geargnasher]

+1 Rocky, I shoot similar boolits to around 2K fps in my .30-30s. Using powder like 3031 and 748 helps the softer boolits get a good start.

Gear

[kelbro]

Thanks for the input. I had considered that but to date, all that I have cast for is pistols and those are under 1600fps.

Reading Ranch Dog's load notes, he lists that he uses WD Lyman #2. I just assumed that I needed harder for 2000-2200 fps.

I'll shoot these and see how they do.

Since they are already cast, checked, and lubed, should I anneal the tips to get some expansion?

Experimenting is half the fun of this hobby. Finding the optimum hunting setup (like finding the optimum load) is kind of a let down for me. Once I nail it, I typically load up a couple hundred and move on to another rifle, pistol, etc...

[Recluse]

In the camp with Rocky and Gear on this one.

With a BHN factor that high, I think annealing the tips will only result in fragging and separation upon impact.

However, experimentation IS three-fourths of the fun, so load yourself up some gallon water jugs, wet newspaper, some 3/4" plywood, some mudballs, etc, and try them out.

:coffee:

[Bret4207]

I simply can't think of a reason to have boolits that hard for the 30-30. I've done the HT thing taking my boolits up well over 30 or 32 Bhn, I forget what it read. They didn't shoot any better than the softer ones. I think you're wasting your time at this point since good designs in the 30-30 of straight WW alloy seem to work very well for hunting.

Better you start off at square one and do some load development and see if the gun likes the boolits, look at grouping, velocity/pressure, what does the gun want?

[kelbro]

Thanks for the responses. I will see how they shoot today. No problem to cast up some more without the HT.

I will try the tip annealing and see how they do with some water jugs.

I may just save these for hog eradication.

May also try these boolits in one of my 308s.

[44man]

For target and accuracy the hard boolit should do very well. But that is a small caliber going too fast for hunting with a hard boolit.
I would want some expansion so my thoughts would be to use 75-25 to 50-50 WW's and pure, then oven harden them. You will need a gas check for accuracy and might even slow them down some.
I can't offer much for a rifle but base it on my experience with alloys in revolvers shot too fast.

[Gohon]

Your BHN should have come out around 19-20 BHN. Odds are the oven was a lot hotter than you thought. Only way to be sure is with a thermometer in the oven to see what the real temperature setting should be for what you desire. If it were me I would just heat treat them again and let them air cool along with the oven and they will return to the original BHN. Of course you will have to lube them again.

[btroj]

I am with 44 man. Add a bunch of pure lead then heat treat. You get a bullet hard enough to drive it fast but it isn't going to be brittle.
I have started to cast all my bullets softer than I used to. Save my hard allot for loads that require them and gives me bullets that do what I want.

[1Shirt]

Couple of years back I bought a toster oven (at Good Will for $3.00) to try heat treating. Cast, checked and sized a group of 22's. Put about 50 of them in the oven, and promptly proceeded to weld them together from overheating. Cheap lesson and learning experiance.

Gave up the idea of heat treating right then, and I stay with just water quenching both for convenience and hardening. Have water dropped for more years than I care to think about. I am primarily a rifle shooter. I like hard blts for paper, particularly for small cals (22-6MM). Most of my paper shooting is done at under 1800 fps, so really don't need lino hardness, but don't feel that it hurts to be at that hardness level. Lately I have been playing with a lot of Trail Boss loads in a number of different ctgs. Probably ought to air drop a bunch for these just to see if there is any difference between the air drop and water drop accuracy wise with low vols.
1Shirt!:coffee:

[kelbro]

Your BHN should have come out around 19-20 BHN. Odds are the oven was a lot hotter than you thought. Only way to be sure is with a thermometer in the oven to see what the real temperature setting should be for what you desire. If it were me I would just heat treat them again and let them air cool along with the oven and they will return to the original BHN. Of course you will have to lube them again.

Thermocouple shows the oven to cycle between 420 and 430 repeatably. May try to re-heat them and let cool naturally. Outside though since they are lubed with 45/45/10 :)

[Gohon]

kelbro, I once had to re-do some bullets I had already lubed with 50/50 LLA and JPW. Except in my case it was to heat treat some non heat treated casts. Anyway, what I did was put the cast bullets into a quart jar and then filled the jar with gasoline. After swishing them around a little the lube was removed. Poured them out through a strainer and them spread them out to air dry for a day. Didn't have to put up with smoke pouring out of the oven or lube hard baking on the bullets.

[243winxb]

Lyman - Heat Treatment of Cast Bullets to Harden Them


Quote:
Q: Is there anything I can do to make the bullets harder?
A: Cast bullets can be heat treated to increase their hardness providing your alloy has some antimony present. To heat treat your bullets: Cast your bullets in the normal manner, saving several scrap bullets. Size your bullets but do not lubricate them. Place several scrap bullets on a pan in your oven at 450 degrees and increase the temperature until the bullets start to melt or slump. Be sure to use an accurate oven thermometer and a pan that will not be used again for food. Once the bullets start to melt or slump, back off the temperature about 5 to 10 degrees and slide in your first batch of good bullets. Leave these in the oven for a half hour. Remove the bullets from the oven and plunge them into cool water. Allow them to cool thoroughly. When you are ready to lubricate, install a sizing die .001" larger than the one used to initially size them. This will prevent the sides of the bullets from work-softening from contact with the sizing die. Next apply gas checks if required and lubricate. These are now ready for loading.

[mdi]

I don't hunt a lot, but I understand the nose shape of the Ranchdog design (large meplate) does considerably more tissue damage then some other shapes and does not need to expand. Large meplate and penetration gets the job done?

[btroj]

A large meplat is a factor in ability to kill cleanly. But the 30 Ranch dog has a large for caliber meplat but it is small compared to 44 or 45 bullets of similar design.
In a 30 I want at least a small amount of expansion to increase wound size. Not enough to flatten the bullet but enough to get to 35 cal or so. And you sure don't want a bullet this size to break up or penetration will suffer.
The league meplat really comes into play in the bigger bores. For a 45-70 expansion isn't really as critical as it's nose is already the size of what a 30 hopes to become after impact.

[Gohon]

Below is the chart I use......much easier than the Lyman method and very accurate in my tests.

http://i51.tinypic.com/vghma1.jpg

[Nrut]

I put them in the toaster oven @ 430° for an hour. Took them out and tested them an hour later. They all measured around 28BHN and are a very dark gray color. I have HT'd 44 bullets before and don't recall them getting that hard or changing to that dark of a color.
-----------------------------------------------------------------------------------------
kelbro,
Did you water drop your boolits directly from the oven?...
According to your original post above you left them in the oven to cool down which means you annealed your boolits not HT them..
Annealing should have given you a BHN of around 7-9 just after 1 hr. of cool down..
I am confused..:veryconfu:shock:

As far as annealing the noses, that's a grand idea..
The 2% Sn that you added should tone down the brittleness of your alloy making for a perfect boolit if your rifle shoots them to your satisfation...
Testing on water jugs and/or news print will give you an idea on the terminal effect of your boolits and if they suit your needs..

[kelbro]

Sorry, I left that detail out. I dropped them immediately into a sink full of icy water.

This alloy tests right at 8 BHN AC, an hour after casting.

In the past, I just used a foil 'boat' to hold the boolits. This time I used little meatloaf pans. Maybe those confines generated what was apparently a lot more heat, I don't know.

I wish that I had seen the post above about the gasoline stripping the lube before I put those back in the oven. Apparently the 45/45/10 has a much lower melting point than straight LLA. What a mess! Just threw them all back in the pot and started over. Scrapped about 70 gas checks :(

BTW, the 28 BHN boolits squished in the vise, no brittleness. Didn't try the tip annealing.

[AZ-Stew]

I question your measurement accuracy when you say it only took an hour for the boolits to go from 8 to 28 BHN after heat treatment. I've done some heat treating and found that it took a day to get to 26-28 and a second day to reach 30. Didn't measure any after that as I had arrived at the goal I had set and I expected little further hardening over the next week or so. I use a toaster oven I bought at a yard sale for $10. I wrote it up here a couple of years ago. If you're interested in reading it, do an advanced search using my screen name and the keyword "toaster".

In order to avoid the issues with the lube, size them and seat the 'checks, without lubing them. After heat treatment and allowing them to dry, go back and lube them using a die .001 larger than the sized diameter.

Other than that, you seem to be well on your way. As others have said, adjust alloy composition for the job to be done. Keep in mind, though, that the lower the percentage of antimony with respect to the lead content, the softer the boolits will be, regardless of heat treat technique.

Regards,

Stew

[mroliver77]

In my toaster oven there is nothing between the heating element and the rack. Most need some kind of barrier or heat sink to buffer the heat when the element is red hot or overheating of alloy will occur. Many fix a sheet of 1/8" steel below the top element and/or above bottom element depending on the model. I use a plate on the rack to help smooth the heat fluctuations from cycling off and on.
For maximum heat treating use the slump method to adjust oven. Different alloys need readjusting maximum temperature. I try to use the least amount if antimony possible and rely on maximum heat treating to get the hardness desired.
A hard, tough .30 cal boolit with a 50% or better meplat, driven at 2200+ fps, will leave a
1"+ wound channel in a deer or hog and also drive deep into vitals. I personally like to drive them faster to flatten trajectory and reduce guestimating errors.
In my M1 Garand I was using the 311413 boolit hardened to 28 brinnell pushing it 2400fps and getting 4"-5" groups(8 shot) at something like 130 yards to one steel target we have set up. I wondered why I could not get it better than this grouping. I then read that this boolit does not shoot well past 1600fps or so. I figure that the extreme hardness helped to support the pointy nose section and boolits were as fat as would feed reliably. I had a point in mind about the M1 loading but it must have been b.s. as it is gone. lol
Anyhow, I would have tried them. Just possibly you might have stumbled on to an accurate load if nothing else.
Jay

[kelbro]

I did shoot some of them. Full power loads. 31gr of 3031. Shot 2-3" at 100 with buckhorn sights and 50 year old eyes. Not too shabby. No leading.

[243winxb]

The higher the % of antimony, the faster the alloy will harden after heat treating/water cooling.http://www.keytometals.com/page.aspx?ID=CheckArticle&site=ktn&NM=88
The alloy containing 2% Sb clearly does not respond sufficiently to be considered as a possible alternative. The 4% Sb alloy, however, attains a hardness of 18 HV after 30 min, and the alloys that contain 6, 8, and 10% Sb could be handled almost immediately

[MtGun44]

+1 on what Bret said - but for me it is in the mag pistols.

Bill

[nanuk]

Ok. Some questions
WRT HT WW alloy (I love acronyms)

1) HT WW and after ½ hr, WQ. Gets them HARD. The higher the temp, the harder. Does water Temp make a difference?


2) Heat WW up to near melting and let rest to cool slowly in OVEN will remove ALL temper and make dead soft ?(well, as dead soft as the alloy can be?)


3) even the hardest alloy will squash in a vice. May take more effort but will show little? Would taking a HT boolit and hammering it with a a 3# hammer cause it to shatter? Could this be a test for “Brittleness”?

4) is there a way to “Flash” heat a boolit to harden only the surface, if harder is needed for a specific gun, but keep the internal metal softer/tougher for less fragmenting upon impact?

5) when softening the Nose, does it need to get hotter than when it was HT, or just as hot, and then slowly cooled?

6) can one soften noses by setting up a shallow pan of water in hot oven, bring to temp, then allow to slowly cool? (all the while ensureing the water level stays near optimum level?

7) does HT make a boolit brittle? if HT to same hardness as Lino, will it be as brittle?