Printable View
Well recokon I'll give up on mixing my own alloys from scratch.. for now... But question between super hard and linotype ( buying from roto metals not scrounging) which one of these is better for mixing consistent alloys ? Roto says they can't guarantee the BHN of super hard due to the crystaline structures. Would really prefer something I don't have to g though and check every Ingot with my tester.
The sole purpose of Super Hard is to be a delivery mechanism for antimony to the softer base metals many of us are scrounging. The idea is you already have a lot of free or cheap locally-sourced stuff; you don't want to buy more lead because you have plenty - it's just too soft as it is.
Linotype can also be an antimony delivery system, or can be a decent rifle alloy as is.
Your best end game is to look at what you want to make, and suss out the shortest and cheapest path to get there. Once you figure out the mix, there's really not much more to "making alloy" than dumping it in the pot and throwing the switch. Head scratching for head scratching's sake will likely lose it's charm in short order.
As to the consistency of Super Hard, I'll let others chime in on the actual metal, but the way to approach that is with a small test batch of bullets on the hardness tester. Once you figure out your "lot number" of Super Hard, you can come up with a mix that gets you the BHN range you want.
The other thing to consider is just how much "consistency" is actually required. While there is the extreme "NASA" side of bullet casting where maximum control of variables matters, ending the life of an overly aggressive dog food can inside of 100 yards is not that game. If Daniel Boone's long rifle actually needed Chinese silk patches and 6-times-filtered whale oil to lube them, the United States would still be entirely East of the Appalachians. Good lab technique is worth practicing, but the wise man tempers that against the practicality of what the job really needs.
Linotype is best, as it contains tin & antimony. Linotype is currently $10 less then super hard. Buy enough to get free shipping. Minimum of $149.
I add 2" of the Rotometal bar to a Lee 10 pound pot of wheel weights. If pure lead, add same for target loads, more for magnums. https://www.thehighroad.org/index.ph...hart.3536/full
Note that all alloys have tin in them. It's there for a reason.
Superhard is 30% Sb, lino is 12 + tin. Tin is expensive. Superhard now comes in nuggets, easier to use. High Sb BHN is difficult to measure due to the crystals, doesn't mean it's not high BHN. I don't use tin, no need unless for expansion in HP pistol rnds.
I've had a problem with that Lyman BHN chart for some time, especially after I started measuring BHNs. The chart says lead has a BHN of 5. The National Institute of Standards says 100 % pure lead has a BHN of 7. I got some certified 100% pure lead and sure enough, the BHN measures 7.
However, I have been using the Lyman formula for #2 alloy using Linotype, lead and tin for years. The BHN measures out correct to the chart and #2 alloy has proven to be the best alloy for rifle cast bullets shot at 1800 - 3000 fps if accuracy is the name of the game.
I am a fan of Superhard in my range lead with some tin.
Super hard, pure lead and tin will allow you to make precise content adjustments of the 3 constituents in any reasonable alloy configuration you choose.
Linotype, lead and tin will constrain your adjustments by the tin to antimony ratio in the source alloys.
You want super hard, pure lead and tin.
Quote:
Originally Posted by Wolfdog91
I'm sorry to hear you're giving up on your project. Hope you reconsider soon.
About the inconsistent hardness of Super Hard, the reason is, it's not a true homogeneous alloy. The maximum amount of Sb that can be alloyed with Pb (IIRC) is about 4%. So you have an alloy of 96% Pb / 4% Sb and a bunch of chunks of crystalline Sb floating around in it.
I don't know how Rotometals gets a consistent mix but I'm sure they have it figured out so when you cut off a chunk you can be confident that it will be the same composition as the next chunk.
So now you have the amount of Sb you want in your finished alloy but it's not in the form you want. It's still crystalline Sb floating around in your lead....
Just like when I crush the Sb ingot and dump it in my lead.
The difference is, Rotometals has done the hard part. Their Sb is already submerged in the Pb and protected from oxidation. All you have to do now is add some Sn and that will allow the extra Sb to dissolve into a true alloy. It doesn't work without the Sn.
Normal flux and stir will complete the process.
Starting with linotype is a bit simpler. It's already an alloy and will easily mix with your other metals. 50/50 with pure lead is "Teracorp Hardball" alloy and will work well for most of your handgun and rifle needs.
Hope this helps.... or at least doesn't add to the confusion.
Jerry
Sb allows you to heat treat your boolits, so the hardness statement from Rotometals is not so concrete. You can towel dry or water drop for different hardnesses. You can slowly heat finished boolits, cook them at that holding temperature, and then slowly cool them down to get ultimate softness. You can probably take the ultimate soft samples, raise them to a specific temperature, hold for a period of time, then water drop. Sb content, holding temperature, and holding time would effect the final hardness.
*
I’ve only read about those things, so maybe I’m way off. I have more fundamental aspects of casting yet to master.
There’s a fellow in the swapping and selling section with foundry type for sale for half of what rotometals is charging for that super hard. 20 lbs for $63 vs 5 lbs for $32. I know what I’d be buying if I needed it.
O I have giving up 100% I'm still. Really really wanting to do it it's just eevyon keeps talking about super hard and just getting something already hard so egh, figured I might as wellQuote:
Originally Posted by KYCaster