View Full Version : water quenching,dropping
07-24-2010, 04:26 PM
this may be a stupid question but here goes
is there any difference between a air cooled bullet and a water dropped bullet ?
I waould like to know if it hardens the bullet and if so how much ???:Fire:
Muddy Creek Sam
07-24-2010, 04:28 PM
If you air cool the isotope it is 10 to 10.5 BHN, if you water quench it is 17-20 BHN.
Hope that helps,
Crusty Deary Ol'Coot
07-24-2010, 04:49 PM
It is also a very simple process.
JUST MAKE SURE AND KEEP THE WATER AWAY FROM THE MELTED LEAD!!!!!!!!!!!!!!!!!!!!!!!!
I like to cast with a partner because of the large production allowed by using 5 or so molds at one time.
I pour with a bottom pour ladle from a good sized pot over an OLD Colman gas stove, while the partner takes the molds, in rotation, turns and drops the hot boolits onto a large bath towel floating in the 5 gal bucket of cold water.
The towel will slowly sink, at which time a stick comes in handy to reach into the bucket and reposition the towel back to the top.
I have found if the boolits are dropped into the water without the towel, spounge or??, they dent each other when they hit the boolits already at the bottom of the bucket.
Keep em coming!
Crusty Deary Ol'Coot
07-24-2010, 04:50 PM
Lead alloys with antimony harden when quenched from around 450F. It takes time
for this to happen.
Use search function for more info, please.
07-24-2010, 04:51 PM
no need to shout.
07-24-2010, 05:07 PM
Given the proper alloy, rapid cooling of boolits will harden them. Not instantly, but over a period of days or weeks after cooling. There are two methods to do this:
1.) Drop the boolits into a bucket of water as you release them from the mould.
2.) After casting, if you're going to size the boolits, it's better to size them and attach any desired gas checks, then heat the boolits to between 425 and 450 degrees F. Measure this with an accurate thermometer. Don't rely on the markings on the oven knob. After an hour soak at temperature, immediately quench the boolits. Lubrication can be added later using a sizer die .001 larger than the sized boolit.
Wheel weight alloy hardens quite a bit. It will harden more if you add a percent or so if hard lead shotgun shot, which will add a touch of arsenic to the lead, tin and antimony of the wheel weights. Alloys of lead and tin alone will harden very little, if any. Antimony is required for hardening, arsenic added hardens more.
All that said, I've hardened .30 caliber boolits to 30+ BHN using the oven and quench method. The alloy was wheel weights with a touch of tin added to improve casting qualities.
Linotype is another hard alloy, and you don't need to quench it for most purposes.
A question for you is, do you NEED really hard boolits? Most pistol and revolver shooting can be done with air-cooled wheel weights.
07-24-2010, 06:42 PM
+1 on "most pistol and revolver shooting can be done with air cooled wheel wts"
I find no need to water drop when I get great results with air cooled.
07-24-2010, 06:53 PM
Leaving the armchair scientist to themselves, I have a 'good old boy' answer for ya. By the time I was done casting a couple hundred 7mm bullets and dropping them in the 5 gal bucket of water, they'd hardened quite a bit. It's simple, you pick up a sprue pile bullet and get one out of the water bucket. Then, you hit each one on the nose of the bullet with a sledge hammer (try approximating the same impact). You'll see the difference in one afternoon right in front of you.
The BHN scale is a little like decibels, each increment is 10 times the previous. So 5 bhn is 50 times harder (if you have a grasp of what crystalline grain hardness is, not sure I do). Anyway, some of what you read online can be circumvented with a little experimentation- this time by sledge hammer.
Give reality a try,
Powered by vBulletin® Version 4.2.3 Copyright © 2016 vBulletin Solutions, Inc. All rights reserved.