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Dave L
03-17-2010, 07:52 PM
I've been lurking around this site for a while. Finally joined. I've got a question I hope one of you knowledgeable guys will have an answer to. My shooting buddy and I are shooting a lot of cast boolits lately and have gotten into harnesses. We were wondering what the hardness number is for a typical jacketed bullet. We are getting around 20 for our hard cast and were wondering how close we were to the hardness of a jacketed bullet. Our hardness gauge is his and he worries that a jacketed bullet will somehow damage the gauge. So here I am asking what is the hardness number for the jacket on a jacketed bullet?
TIA

outdoorfan
03-17-2010, 08:14 PM
I think it's upwards of 40, but I'm not sure.

runfiverun
03-17-2010, 09:28 PM
iirc copper is closer to 50-56 bhn.

RayinNH
03-17-2010, 09:41 PM
http://en.wikipedia.org/wiki/Brinell_scale

About halfway through the article they have a chart for some common materials. Copper is listed at 35 BHN...Ray

Dave L
03-18-2010, 12:14 AM
Thanks for the replys guys. The article from RayinNH answered the question. So I guess the next question is, just how hard can you get lead boolits? We are getting in the low 20s but I'm sure there are alloys that will give a lot harder bullets. And why isn't everyone trying to make their lead boolits as hard as possible?

reloader28
03-18-2010, 12:27 AM
I aint been doing this long, but I've been oven heat treating plain WW lead at 475 degrees for 1 hour and getting 30 BHN.
I've only been doing some rifle test bullets and my brothers 500 S&W.
I might water drop some 44's when I get the chance. I aint tried that.
All my other loads I just dont need that hard.

cbrick
03-18-2010, 02:47 AM
why isn't everyone trying to make their lead boolits as hard as possible?

Simply because harder isn't better, it's just harder is all. Many times harder can cause more problems than too soft. You need to match the alloy BHN to the pressure of the cartridge.

The vast majority of loads need nothing above 18 BHN and many will work better much softer than that.

You can only make an alloy hard to a point with the addition of antimony, after that the alloy is useless as bullet alloy, here's an example of a monotype bullet that broke in half simply chambering the round.

Rick

dubber123
03-18-2010, 08:00 AM
I have always fought with getting high velocity in rifles with WW boolits, heat treating up to 30+ Bhn, different lubes, firelapped bores, nothing helped. Then some of the fellas here on the forum told me to use 50/50 WW-pure lead, water dropped. I couldn't fathom how a softer boolit would help, but gave it a try. Guess what, ALL my leading problems went away.... Harder is not always better, and that is one of the most valuable lessons these guys have taught me.

armyrat1970
03-18-2010, 08:21 AM
I have always fought with getting high velocity in rifles with WW boolits, heat treating up to 30+ Bhn, different lubes, firelapped bores, nothing helped. Then some of the fellas here on the forum told me to use 50/50 WW-pure lead, water dropped. I couldn't fathom how a softer boolit would help, but gave it a try. Guess what, ALL my leading problems went away.... Harder is not always better, and that is one of the most valuable lessons these guys have taught me.

It is true. Harder is not better. Now this depends on how fast you drive the boolits also. A hard boolit driven to fast will skip over the lands and create more leading problems. There is a reason many just cast with straight wws, or at the most, waterdropped wws. I believe a BHN of around 14 or 16 is plenty hard enough for any application with cast boolits.

sqlbullet
03-18-2010, 10:55 AM
To avoid leading, fit is king, lube is queen. Hardness is way down the list.

Keep in mind back when most rifle bullets were lead, hard-cast lead was a BHN of 12.

Copper is harder than lead, but it has many other properties that allow it to work well at that hardness. It is very ductile, it doesn't gall the same way when abraded against steel. It does copper foul, but only to a point.

I have cast bullets that were treated to a hardness of 32. I did not shoot them at that hardness. I was helping my son with a science fair project and we were seeing, among other things, how hard we could get a 96-1-3, lead-tin-antimony alloy.

Like armyrat1970, leading issues I was having in my 10mm went away when I went to a softer bullet. I was water dropping, and I switched to air-cooled. Later, I learned more, slugged the gun, and found out my bullets didn't fit great. Bore slugged almost .401", same size as the bullets. I honed out the sizer to .402, and now can shoot the really hard ones as well without issue, but don't bother anymore.

Hard bullets are harder to size, and require water to be in the casting area. Except for my .309" bullets for my Garand and 300 Win Mag, everything is air-cooled now.