What hardness should I try for?

[BSJI]

I'm getting back into casting after about a 15 year layoff... Never worried about alloys and stuff back then so I've been trying to catch up. TONS of new stuff to learn here!

I can get my old stuff tested at work and I've learned, so far, that a lot of it is 97% lead without any SN and less than 1% SB . Got another 100 or so pounds of old surcharge soils testing weights that have .5% Niobium in it! I've also just converted about 25# of 7.5 shot into ingots so I can use it to harden the rest of my stuff... I'll get some solder for the SN


Anyway, my dilemma is that I want to shoot my rifle like a pistol and my pistol like a rifle...

I going to shoot sub-sonic 45gr bullets in my bolt action .223. And I've got a blow-back 9mm carbine, so I need to push them fast enough to cycle the action.

What sort of alloy/hardness should I be trying to create?

[62chevy]

All depends on how fast you want to shoot them, fast means harder. To figure what to use to harden your lead get the Alloy Calculator.

http://castboolits.gunloads.com/showthread.php?105952-Lead-alloy-calculators

[jonp]

I use that and the pressure recommendations. Both seem to give a good starting point

[62chevy]

I use that and the pressure recommendations. Both seem to give a good starting point

The pressure recommendations that Lee put in their reloading manual?

[jonp]

http://www.lasc.us/CastBulletNotes.htm

[62chevy]

http://www.lasc.us/CastBulletNotes.htm


That's a good one but missed it some how in the past.

[jonp]

The link is on the bottom of this page on the right. There is some good info there

[RegisG]

What great information. some a bit deep for me but, the part on hardness is exactly what I needed to know. I have been quenching directly from the hot mold and (pencil) hardness is something a little over 20 as best I can tell. It seems like I can shoot for a 12-15 Bhn air cooled and if I want harder (for hotter loads), I can simply water quench and end up a little over 20.
Am I thinking correctly here?

Thanks,
Regis


http://www.lasc.us/CastBulletNotes.htm

[RobS]

What great information. some a bit deep for me but, the part on hardness is exactly what I needed to know. I have been quenching directly from the hot mold and (pencil) hardness is something a little over 20 as best I can tell. It seems like I can shoot for a 12-15 Bhn air cooled and if I want harder (for hotter loads), I can simply water quench and end up a little over 20.
Am I thinking correctly here?

Thanks,
Regis


Sounds about right. The 9mm is a tough case especially down toward the web/head of the brass. Make sure the case isn't swaging down on the boolit and making a smaller diameter than you are wanting. Many have best luck sizing 9mm to .358" should they chamber fine.

[Outpost75]

I use 1:30 tin/lead for subsonic revolver loads in cartridges such as the .38 Special, .44 Special, .44-40, .45 Colt and .45 Auto Rim, as well for any plainbased rifle loads below 1400 fps which do not require a gascheck. For gaschecked bullets from 1400-1800 fps I use 50-50 linotype and plumbers lead, which runs about 13.5 BHN. Above 1800 fps I use 50-50 wheelweights and linotype which runs about 16 BHN and this runs up to 2000 fps for full charge loads in the .30-30 and for cast loads adequate to cycle the M1 Garand. There is no need for water dropping, quenching or any of that nonsense if the bullet "fits" and is properly lubricated.

[Yodogsandman]

As long as your alloy has antimony (Sb) in it, you can heat treat it to gain hardness for free! Accomplish this by either by water dropping from the mold or oven heat treating and quenching.

Use only enough tin (Sn) to get complete mold fill out.