BHN of Water Dropped Lead

[Jeff82]

Does anyone know the BHN of pure lead that is water dropped? Ive been surprised that the BHN of my bullets using 0.8% Antimony and 2.0% tin is still about 13.4. I'm trying to get my BHN down to about 10.

Thanks.

[ShooterAZ]

Water dropping pure lead won't make it any harder. The alloy must have antimony in it in order for further hardening. Don't WD it and you should be about there.

[captaint]

Just use straight up WW's and air cool them. They'll come in around 10 or 11. More often, I use 50/50 WW's & softer lead and air cool that. It's usually around 9. I don't water drop anything, but then, I don't shoot higher vel rifle boolits, either. Mike

[montana_charlie]

Ive been surprised that the BHN of my bullets using 0.8% Antimony and 2.0% tin is still about 13.4. I'm trying to get my BHN down to about 10.
I don't know exactly, but adding 2% tin to pure lead will bring it up to maybe 6 to 6.5 BHN. Adding 0.8% antimony can't increase the hardness very much.
Heck, it takes a full 4% to get wheel weights up to 12 BHN.

I don't know how you measure hardness, but I bet that (either) your antimony content is higher than you state ... or 13.4 BHN is an erroneous reading.

CM

[bobthenailer]

Ive never done it with straight PB ! but i have WD 50/50 coww /pb comes out around 15 bhn.

[Jim Flinchbaugh]

most of my ACWW are around 9, pure (roof lead, plumbing pipe) is much softer.

[Jeff82]

Thanks for the responses. I may have to switch to air cooling as even small amounts of antimony seem to really harden up the alloy, and it gets hard to consistently match BHNs when trying to blend really small percentages of antimony. Mabye I'll take a shot at 50/50 ww/pb or 2%sb/2%sn air cooled.

[montana_charlie]

Mabye I'll take a shot at 50/50 ww/pb or 2%sb/2%sn air cooled.
Since you are looking for an alloy that is on the soft side, a very good one is 97/1.5/1.5.
Your idea of using 96/2/2 is also good, and may hit the hardness you want.
The best thing about both of them is the fact that tin and antimony are equal in percentage.
It makes for a very stable alloy ... speaking about hardness changes over time.

CM

[Jeff82]

1.5%/1.5% sounds good. The other thing that's ocurred to me is that, if I don't water drop, I could blend the ingots to the hardness I want before casting. That way I'd know beforehand what the BHN would be. With water dropping I have to estimate what the hardness will be a week or so after I've cast the bullets. Seems simpler to air cool.

[curator]

Jeff82,

0.8% antimony? If that is accurate, back off on the tin content to slightly less than 1% and continue to water drop-quench. You should come up to complete hardness within 2 days. Air-cooling will give less hardness but also takes about 2 weeks to come up to potential hardness. Generally, tin content that exceeds antimony content may produce an non-uniform alloy. Salvaged .22 rim fire bullets from indoor ranges are about 1% antimony, and adding about 1/2% tin makes a good .38 special wadcutter alloy with a BHN of about 7.5. Water drop-quenching them gives a BHN of 9.5-10 after two days.

[montana_charlie]

1.5%/1.5% sounds good.
That alloy will test at 8 BHN right after casting. By the 24 hour point it will test at 9.8 - 9.9 BHN ... and will stay at that hardness (basically) forever.

That is the 'stability' produced by matching tin and antimony levels.

Anybody wanting a 'formula' for creating this alloy can get it by combining 3 parts Lyman #2 with 7 parts pure lead.
The guy who did the year-long test to determine the hardness and stability (I claimed above) calls this his "three - seven alloy".

CM

[mefunkymxw]

my air cooled WW ingots are about a 15-16 BHN, my water quenched 44s are reading at 22-23 BHN, im not sure how correct these readings are though... i am using a lee lead hardness tester.

[Charlie Two Tracks]

http://castboolits.gunloads.com/showthread.php?105952-Lead-alloy-calculators
check that out. Comes in handy. Plug your amounts in and find out what you get.