Unknown alloy

[briankk]

I have some suff that is described as radiation shielding, 25lb blocks. I melted 10 lbs in my Lee pot, and cast some 9mm. The mold is an aluminum Lee TL356-124-TC.

I flux with Marvelux and top pour with a ladle.

The resultant bullets, dropped onto a damp cloth, weigh 130gr, (not the advertised 124 gr) are BHN 30+, and look as though they are of pure chrome, shiniest bullets I ever cast. The do not fill out the lube grooves very well, and shoot all over the target, though they do not lead the barrel. I's shot 'em with NRA lube, and Lee liquid alox, no difference.

Another odd thing, when I pour the mold, the sprue does not get a shrinkage dimple in it as it cools.

So.. What is this stuff, anyway? Short of sending it to be analysed on an SEM, is there anyway to figure out what this alloy is? Chemical test or something..

[chemist308]

Try oxidizing some of the material with peroxide--do it outside and wear glasses. See if it turns lead oxide white. If that doesn't work, try some with bleach and some with acid.

Edit: Do not mix these solutions, obviously.

[briankk]

Try oxidizing some of the material with peroxide--do it outside and wear glasses. See if it turns lead oxide white. If that doesn't work, try some with bleach and some with acid.

Edit: Do not mix these solutions, obviously.

10 min. in 3% peroxide, still bubbling, turning slate grey

10 min in 5% vinegar, no reaction

10 min in Clorox "regular" bleach, no reaction

[runfiverun]

my guess would be 5% antimonial lead.
since you water quenched them the 30 bhn would be about right.
what size did you shoot them at?
a lot of 9mm's have bbls in the 357-8 range.
you might want to try cutting the with lead or adding a bit of tin to the mix and measuring what you have and need.

[briankk]

10 min. in 3% peroxide, still bubbling, turning slate grey

10 min in 5% vinegar, no reaction

10 min in Clorox "regular" bleach, no reaction

Hour and a half..

Vinager and bleach, nothing, no reaction.

Peroxide.. Still fizzing, slate grey giving way to olive green color..

[briankk]

my guess would be 5% antimonial lead.
since you water quenched them the 30 bhn would be about right.
what size did you shoot them at?
a lot of 9mm's have bbls in the 357-8 range.
you might want to try cutting the with lead or adding a bit of tin to the mix and measuring what you have and need.

I shot 'em as cast, .358 on the driving bands, .355 on the lube grooves, shot from a S&W 99 compact.

Also cast some ammo for my SKS, same stuff at .311, Hornaday copper gas checks and Lee lube, arrive at 50 yard target going sideways, perfect bullet profile in the underlying tar paper. Probably about 11-1200 fps, not quite enough AA1680 to cycle the action (14.5 gr). Bullets weighed 162 gr..

[StarMetal]

Often a recovered bullet (in good condition preferrably) is a good clue as to what is happening while it's in the barrel.

Joe

[snaggdit]

Also cast some ammo for my SKS, same stuff at .311, Hornaday copper gas checks and Lee lube, arrive at 50 yard target going sideways, perfect bullet profile in the underlying tar paper. Probably about 11-1200 fps, not quite enough AA1680 to cycle the action (14.5 gr). Bullets weighed 162 gr..

If you have any 4198 try 21gr or 4895 try 26gr. These loads will cycle the action. Can't speak to the sideways boolit issue, though.

[briankk]

If you have any 4198 try 21gr or 4895 try 26gr. These loads will cycle the action. Can't speak to the sideways boolit issue, though.

Normally, I'd use 24 gr of 1680 under a 123 gr bullet, with this much heavier 162 gr bullet I decided to be cautious. Was going to go to 18 gr next, but increasing the charge seems unlikely to straighten out the sideways bullet..

Nothing against 4198, I just don't have any on hand, shot it all up in my .45-70.

[243winxb]

Bismuth alloys containing high percentages (50% +) of Bismuth will grow bigger in diameter after 3 days. Under 50%, if i remember correctly it may shrink bullet diameter. Radiation Shielding has Bismuth in it. PDF file here> http://www.aimspecialty.com/AIM-fliers/Radiation-Shielding%20Alloys.pdf More on Bismuth here > http://www.alchemycastings.com/lead-products/fusible.htm Any alloy with Bismuth in it is not usable for casting bullets. IMO. A test might be to cast bullets, measure the diameter, wait 3 day, measure again, did they shrink or grow in diameter? The tempture that the alloy becomes liquid at may also be another clue. Bismuth melts at a lower temp. then standard Lyman #2

[runfiverun]

sounds like zero rifling engagement.
bismuth is an excellent hardener for lead also,but rather expensive.
it is also brittle in larger quantities.
you are gonna have to investigate some.

[243winxb]

Any alloy with Bismuth in it is not usable for casting bullets.

[briankk]

Bismuth alloys containing high percentages (50% +) of Bismuth will grow bigger in diameter after 3 days. Under 50%, if i remember correctly it may shrink bullet diameter. Radiation Shielding has Bismuth in it. PDF file here> http://www.aimspecialty.com/AIM-fliers/Radiation-Shielding%20Alloys.pdf More on Bismuth here > http://www.alchemycastings.com/lead-products/fusible.htm Any alloy with Bismuth in it is not usable for casting bullets. IMO. A test might be to cast bullets, measure the diameter, wait 3 day, measure again, did they shrink or grow in diameter? The tempture that the alloy becomes liquid at may also be another clue. Bismuth melts at a lower temp. then standard Lyman #2

Most of the alloys listed above melt below boiling, so I nuked a pyrex cup up to a full boil and chucked a bullet in there.. Nothing. Did not melt or soften or deform. Still there are 4 or 5 alloys with higher melting temps that I can't test..

The first lot of this stuff I melted (rifle bullets), I'd set the pot at my usual 750 degrees, no issues other than it seemed to take longer than normal to heat the mold enough to llose the wrinkels. The batch yesterday I melted under a hood a 850 degrees, no change in the end product. I do not have a thermometer to test the actual melt temp, I'm going by the Lee rheostat markings..

[briankk]

sounds like zero rifling engagement.
bismuth is an excellent hardener for lead also,but rather expensive.
it is also brittle in larger quantities.
you are gonna have to investigate some.

It does sound like the bullet is too small. (sigh) Guess I'm going to have to Cerrosafe my bore diameters...