Could some one check me on this lead/tin mix for 9mm?

[SteveK]

I just cast about 500 122 gn. 9mm boolits and tried something new (to me anyway) and I'd like your opinion on my plan:

Having exhausted my supply of WW alloy, I cut into a 100 lb ingot of lead I had at the house to cast a few plinkers. Being concerned that pure Pb would be too soft for the intended round to be loaded up with about 3.4 gns. of 700x powder, I went to the hardware store and bought 1 pound of 50/50 lead/tin solder which I mixed in the furnace with 9 lbs. of pure Pb. I fluxed w/paraffin, stirred, skimmed and cast about 500 rounds. At first I had quite a few culls due to short fills and then some funky worm patters on most of the others. The worst of these were all recast later. After increasing the heat of the furnace a bit, I started getting some decent looking boolits. The only thing was they seemed to stick more in the Lee mold. I plan on letting the boolits age harden for a couple/three weeks before I load'em up.

My questions:
1. Does anyone foresee a problem with my alloy considering the powder load I plan to use? If so, please elaborate.
2. Was my diagnosis of the cull problem, e.g., too low a casting heat, correct?
3. Am I missing anything?

Thanks in advance for your insights.

Steve

[454PB]

The addition of tin doesn't add much hardness, but the only way to tell will be to try loading some up.

Your mixture (assuming dead soft lead) is probably around 7 BHN. Personally, I want 9mm boolits a minimum of 10 BHN, and 12 BHN is better.

[prs]

It is a SiN to waste tin. ;-)

That mix is about a 20:1 ratio and more suited for a few black powder long range loads than 9mm handgun fodder. Do some math to get a 1% to 2% SN content and then add some SB at an equal or slightly higher ratio to get your hardness. Shot gun shot is a fairly easy source of antimony and even a trace of arsenic. Then your air cooled boolits will be a bit harder and if you water drop they will be quite a bit harder.

prs

[MT Gianni]

You will be too soft and lead, IMO. I would buy magnum shot or lino or one of Roto metals alloys to mix with. Chilled shot will not be hard enough. The current alloy should shoot fine in any of the specials [32 long,38, 44] up to 900 fps.

[shadowcaster]

You will be too soft and lead, IMO. I would buy magnum shot or lino or one of Roto metals alloys to mix with. Chilled shot will not be hard enough. The current alloy should shoot fine in any of the specials [32,38, 44] up to 900 fps.

You will be too soft for 9mm. As MT Gianni says.. go to Roto metals and buy something with some antimony in it. I really like their super hard. It's easy to work with and simple to figure out percentages. Keep your tin in the 1 to 2 % range, your antimony in the 3 to 4% range, and either air cool or water drop. Load them up and see what your gun likes.

Shad

[SteveK]

I just keep learning from my disasters... sigh.

[Cherokee]

Steve - not a disaster, a learnig experience. 9mm needs a harder alloy than lower power cartridges. I use a 2/3 alloy (Tin/Antimony) or a 3/3 alloy for my 9's.

[MtGun44]

Shoot a few, you may well find success, esp if you use NRA 50-50 lube in
a conventional lube groove design.

Bill

[fecmech]

The load you intend to shoot is at the higher end for 700x but it might work, you won't know till you try. That said if I had 500 bullets already cast there is nothing saying you can't back that load down a bit if it doesn't work at 3.4. Heck, a little lead in a barrel never hurt anyone!

[MT Gianni]

The load you intend to shoot is at the higher end for 700x but it might work, you won't know till you try. That said if I had 500 bullets already cast there is nothing saying you can't back that load down a bit if it doesn't work at 3.4. Heck, a little lead in a barrel never hurt anyone!

9mm was my first mold, I speak from experience that that is too soft as is 50/50 ww PB.

[SteveK]

Would it be prudent to use if I back down the powder to about 2.9 grains of 700x or 800x to obtain a probable velocity of about 900 fps?

[MT Gianni]

I am afraid it would have to be so slow as to not eject but you could try it.