Any expansion test on copper alloy

[glockky]

I have really been thinking about blending a batch of copper alloy. My plan was to mix 1lb of rotometals #3 babbit to 20lbs of pure lead and 20lbs of COWW.

Before I did I was wanting to know if anyone has done any expansion testing with the copper alloy. I use my rifles to hunt with so a tougher bullet is of no use to me if it will not expand.

[Defcon-One]

Sorry, I have no actual data, but my guess is that hollow points will expand or fragment. FP or RN will not.

This is true with harder binary and tertiary Lead alloys so it should apply even more with the Copper in the mix.

[Maximumbob54]

Hard HP bullets don't expand, they fracture apart. The core in a jacketed bullet is still soft lead but relies on the jacket to hold it together.

[Defcon-One]

Sorry, I have no actual data, but my guess is that hollow points will expand or fragment. FP or RN will not.

This is true with harder binary and tertiary Lead alloys so it should apply even more with the Copper in the mix.



Hard HP bullets don't expand, they fracture apart. The core in a jacketed bullet is still soft lead but relies on the jacket to hold it together.

Bob:

Yeah, So I said fragment, isn't fracture the same thing? Not sure that I get your point!

[lylejb]

Ok,

Looking at rotometals site, #3 babbitt is 84% tin, 8% antimony, and 8% copper, taking the middle of the ranges given.

So, 1lb contains .08 lbs of copper. Dividing that into 41 lbs of alloy, that figures slightly less than to 2/10ths of 1% copper.

Probably not going to make a big difference.

The tin, however, would add 2% tin to the total mix, so that would be about right.

I think you would come out with something close to 96-2-2, and that should be fine.

[popper]

There are some pics of recovered Cu augmented boolits here on the board. Only I have recovered were 40SW from a rock pile, ~15ft. Wt. retention was great and TC nose was ~ same dia. as body. 9mm jacketed were smashed & broken. Cu is a toughener, not a hardener. Expansion is controlled more by Sb, Sn. Your Cu % (0.2%) is fine, it will do the job.

[glockky]

That was the problem I seen with the rotometals #3 babbit high antimony content.