Pewter alloy age softening

[craveman85]

I'm going to start casting for my 44 Magnum soon using the Lee 310 gc mold. I want to try out a 16:1 alloy like Keith developed the 44 with but using pewter instead of straight tin as it's dirt cheap and I already have a ton of it. Question is how long does it take to age soften it? My pewter ingots were all very hard when I cast them last week. How long will it take my bullets to soften. I think that 16:1 alloy should work good for my uses with the gas check and probably only 1300 fps or so.

[Yodogsandman]

If your 16-1 lead-tin alloy contains no antimony, it will stay the same hardness. Pewter does have a small amount of antimony but, not enough to change hardness much, if at all. The US standard for hallmarked pewter is at least 92%tin (Sn), under 6% antimony and under 2% copper.

[craveman85]

I thought that I had read somewhere that it's hard and gets softer over time but couldn't find documentation on it when I was searching. My pewter seems pretty hard. Couldn't scratch it with my finger nail

[Tripplebeards]

I asked the same question when I first got into casting boolits a year ago. Pewter which is mostly tin should not age harden or soften. You can add it to pure lead and whether it's
Quenched or air cooled will be the same hardness. I'm sure I'll be corrected immediately if wrong but the only thing that goes up and down in hardness is a lead mixture with antimony like clip on wheel weights.

I tried casting 16 to 1 last year using pewter. It didn't work very well. I started with pure lead. It tested at 5-6 with my lee BH tester. After adding my 16/1 ratio of pewter I ended up testing it after it air cooled an hour after casting and it only bumped it to a BH of 7-7.5. I tested it a month later and it was the same hardness. I used the alloy in a devistator HP mold and tested at 1575 fps out of my ruger 77/44. I powder coated and gas checked it. It made it into the 3rd Gatorade bottle I filled with water and stopped. I didn't penatrate very well and didn't weigh much, maybe 50-75 grains. If you look at the pics in my profile you can see what was left of the boolit. I casted some 50/50 ACCOWW and pure the day before yesterday and added 2% pewter in my lee 310 mold. I just posted the other day how soft can I cast a lee 310 and I can tell you I wouldn't use my 16/1 pewter mix with BH of 7.5. It's just too soft and would probably look like you threw a grenade at the side of a deer.

BTW my 50/50 mix with 2% pewter had a BH of 10.5 a week after I casted and air cooled it. Which I was told my 16/1 should have been around the same hardness. My coww started Ay a BH of 13.4 and my pure had a BH of 5 to give you an idea of what you'll end up with. I'd tell you to invest in a lee hardness tester like I did. I was just told not go below a BH of 10 when using the lee 310 for my 44 mags by other posters.

At the rate I was going with my pewter and pure lead mix. I would have had to go about 50/50 to get to 11 BH which I wouldn't waste all that pewter when I can use free coww to mix with my pure for the same results.