Mildly scientific alloy analysis

[Beaverhunter2]

I picked up some "bullet alloy" at the scrap yard yesterday. At least that's what the guy who sold it to my scrap dealer called it. It felt (thumbnail scratch test) fairly hard- definitely harder than my pure lead.

Since I don't have a hardness tester and don't have the money for one right now, I figured I'd try checking the weights of some boolits to determine how the new stuff compared to my WW+2% alloy. I casted ten good (although not "perfect) boolits from each of the three melts. Here's the results:

Boolit Weights (grains) Lee 457405 RNFP

Boolit Lead WW+2% BA
1 416.30 409.60 409.60
2 418.50 410.10 410.00
3 419.20 411.60 410.00
4 420.20 411.80 410.90
5 420.50 412.30 411.40
6 420.90 412.40 412.20
7 421.10 412.60 412.90
8 421.40 413.10 413.10
9 422.20 413.30 414.00
10 422.30 414.10 414.10

Average 420.26 412.09 411.82

% of Lead 100.00% 98.06% 97.99%

Spread 6.00 4.50 4.50

Spread % 1.43% 1.09% 1.09%

Average 420.50 412.15 411.81
- extremes

% of Lead 100.00% 98.01% 97.93%

Spread 3.70 3.20 4.00

Spread % 0.88% 0.78% 0.97%


It seems like the stuff is just a fuzz less dense than the WW+2% so it's probably comparable. Do you agree? I did have one more question: Is it common to have this much spread in CB weights? Even after dropping the extremes, I'm pushing 1% variance. Seems like a lot.

Any insight would be appreciated!

John

[runfiverun]

looks like your mold expanded as it heated up.

[Beaverhunter2]

Runfiverun,

The samples aren't shown in the order they were cast- I sorted the weights in Excel to eliminate the extremes. I didn't keep track of the order the boolits were cast. I actually cast about 25 of each alloy and culled to get the 10 with the most consistency (visually). The "bullet alloy" and the pure lead were cast simultaneously. The WW came after because I can only melt two alloys at the same time. Based on the time to harden the sprue, the mold temps were fairly consistent for each alloy.

How much variability do you get in your CB weights?

John

[runfiverun]

on average 1to2 grains after lubing
with some of my rifle molds i pay extreme attention to i can get them down to @ .5 gr
but ya gotta be a bit anal about procedure,temps ,alloy, fluxing,adding to pot ..etc.
it is a process but for rifle stuff i think mandatory.
for my fun guns i don't worry too much about it just go. load and shoot.
i do have a couple that i sweat like for my wesson 445.and for silhouette loads.
but it is just technique, and consistency.

[Beaverhunter2]

Thanks, I'll be careful about getting (and keeping) my rythym. I will say that based on the accuracy I've had with boolits "random run" from this mold and my RD 460s, I hate to think what might be possible with carefully selected boolits!

I think I'm getting hooked! I drove 45 miles each way on the outside chance of finding a new mold to play with. They didn't have it! :(

John

[runfiverun]

thats funny
i get a little nervous when i get a new mold, cause of what i expect from it.
and you may get one that won't work.
then when it does it is a happy moment.