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Rotometals Reclaimed Shot

Posted: Sat Sep 05, 2015 10:29 am
by mtngun
Here's my evaluation of Rotometals Reclaimed Shot. Because I am cheap, I bought their "dirty" shot which they do not recommend for reloading. They also sell clean reclaimed shot, but it costs more.

One bag weighed 23 pounds, another weighed 19 pounds. I did not weigh the other bag.

I did not bother washing the 1st bag of shot that I smelted (the one that I didn't bother to weigh) because I assumed the dirt would be skimmed off in the smelting process. In hindsight that wasn't quite true. The shot appears to be encapsulated in hard clay, effectively forming an "eggshell" around the lead. Even if you heat the shot enough to melt the inner lead, it has a difficult time escaping the shell. I ended up skimming off a lot of shot along with the dirt, so next time I will try washing the shot first.

The first bag of dirty shot yielded 17 pounds and 10 ounces of clean ingots. The yield probably would have been higher if I had washed the shot before smelting.

I have no fancy equipment to determine the chemical composition of the shot -- which Rotometals says is about 3% - 5% antimony -- so I can only test density and hardness.

Density and some other alloys for comparison:

Reclaimed shot -- 2719 grains per cubic inch
Clip-on WW -- 2794
WW + 2% tin -- 2780
Lyman #2 -- 2703
5% tin -- 2776

I was surprised at the density being closer to Lyman #2 than to wheelweight. Either this shot has 9% antimony or else there is some bismuth mixed in with it -- I find it easier to believe the latter, because you would not expect lead shot to have 9% antimony, but you would expect to find some bismuth shot at a shotgun range.

Bismuth is soft and brittle so pure bismuth would make a poor bullet. But I have no data on how bismuth affects a lead-antimony alloy.

Since I always heat treat my wheelweight, I heat treated some sample bullets at 480 degrees F in the shop oven.
Air-Cooled: 15 BHN
After one day: 38 - 42 BHN
After one week: 41 BHN
after one month: 46 BHN :o
after 5 1/2 months: 37 BHN it's going down :x
after 20 months: 29.5 BHN
after 37 months: 26.1 BHN

Re: Rotometals Reclaimed Shot

Posted: Sat Sep 05, 2015 3:56 pm
by mtngun
18 pounds and 8 ounces of clean ingots from the 2nd bag of shot, after I washed the shot.

Washing removed perhaps half the dirt and made it only half as difficult to smelt, but it was still difficult smelting as smelting goes.

Re: Rotometals Reclaimed Shot

Posted: Sun Sep 06, 2015 12:10 pm
by mtngun
The 3rd bag of shot yielded 18 pounds 2 ounces of clean ingot.

Total of 54 1/4 pounds of clean ingot from 60 pounds of dirty shot.

Re: Rotometals Reclaimed Shot

Posted: Fri Sep 11, 2015 7:24 am
by mtngun
So far this reclaimed shot is running ~40 BHN, better than any other alloy I've tested so far. 8-)

The next step is to do a shoot-out side by side with 25 BHN WW and see if there is a difference in accuracy. I've been busy lately so it may be several weeks until I can do the shoot-out.

If there is indeed a difference in accuracy, then I'll send a sample off to be assayed, because I want to understand why this stuff is so hard.

Of course store-bought reclaimed shot is too expensive for plinking, and the hardness is not needed for hunting. But if it improves accuracy, it might be worthwhile for serious target shooting.

Re: Rotometals Reclaimed Shot

Posted: Mon Sep 14, 2015 8:19 pm
by mtngun
UPDATE: I cast some bullets with the reclaimed shot and it cast quite nicely, similar to hardball alloy. Compared to wheelweight, bullets were shinier and the sprue was much harder to cut.

Shot manufacturers usually don't specify the exact chemical composition of their shot. For example, Winchester's MSDS says 1% - 5% antimony, 0.1% - 1% arsenic. Mayco says 0.1% - 6.5% antimony, 0.2% - 2% arsenic. That doesn't narrow it down much, does it? :? In any event this reclaimed shot probably includes a variety of brands and types of shot.

XRF assays may or may not be able to detect arsenic levels. Rotometal's XRF test does not claim to detect arsenic. Apparently some XRF's can detect arsenic but others cannot. In any event XRF tests are not foolproof, so I'm not sure if an XRF test would be worthwhile?

Re: Rotometals Reclaimed Shot

Posted: Tue Sep 15, 2015 5:44 am
by mtngun
UPDATE: Ryan at Rotometals replied to my inquiry about XRF'ing their reclaimed shot.
Yes I have shot it a few times and usually see 4-5 % Antimony,
Our Gun cant see arsenic, but I have heard from manufactures that they used to add 1-2 % to make it harder. And depending how old the reclaim shot or where in the country it was mined it could have more thus making it harder, But that could be different from bag to bag. We don't have or can't alloy in As so I don't thin know can duplicate it
So 1) their particular XRF cannot see Arsenic and 2) reclaimed shot is 4-5 % antimony, which does not explain how it reaches 40 BHN. Nor does 4-5% antimony explain the density of reclaimed shot. There must be something else in the shot that accounts for the density and the hardness.

Also, some internet surfing suggests that small shot has more arsenic than big shot. Well, this reclaimed shot is mostly 7 1/2 and 8, so it probably has a lot of arsenic. If that is the case it debunks the claim that 0.25% arsenic is optimal for heat treating, and it also debunks the claim that high arsenic causes casting problems.

The $25 XRF test on ebay claims it can detect arsenic, so I may have them assay a sample, though I'll still be skeptical of their results.

Re: Rotometals Reclaimed Shot

Posted: Thu Sep 17, 2015 2:54 pm
by mtngun
UPDATE: I heat treated a batch of reclaimed shot bullets the other day at 480F and 5 bullets in one particular spot in the tray slumped to various degrees. The remaining 60 or so bullets were fine, so apparently that one spot gets a little warmer than the rest of the oven.

Next time I'll try 475F. If I still get slumping then I'll try 470F, and so forth until the process is reliable.

Re: Rotometals Reclaimed Shot

Posted: Fri Sep 25, 2015 3:07 pm
by mtngun
OK, here is the assay, and not only were my fears about the limitations of XRF realized, they were exceeded. :lol:

Palladium (Pd) sells for $650 per ounce, so apparently my 55 pounds of reclaimed shot are worth $500,000. :lol: :lol: :lol:

Seriously, I assume the technician had too many beers before filling out this assay, or something. I emailed him for clarification. But regardless of how he responds, obviously I cannot take this assay seriously. I'm not saying he did anything wrong -- other than having too many beers :lol: -- but sometimes XRF machines miss the mark. I was aware of that going into this. I just didn't realize how far it would miss the mark. $35 down the toilet. :cry:

FYI there is a thread on another forum that claims they "proved" arsenic is not needed to heat treat wheelweight because their XRF assay said there was zero arsenic in their wheelweight samples. I hope if nothing else that my assay serves as a warning that XRF assays are not gospel. Sometimes they're pretty accurate, other times they're not, depending on the machine and the alloy. Unless the technician has a lot of experience with similar alloys on his machine, well you just don't know what to expect. :?

Re: Rotometals Reclaimed Shot

Posted: Fri Sep 25, 2015 3:10 pm
by mtngun
I decided that I am in the wrong business. Instead of trying to earn a living making molds, instead I will perform XRF assays for a fee. I don't even have to buy an XRF machine, I can just make up the assay results and it works out about the same. :lol: :lol: :lol:

Re: Rotometals Reclaimed Shot

Posted: Fri Sep 25, 2015 5:06 pm
by mtngun
UPDATE from XRF technician: "sorry for my mistake it is PB AND AL..... IF YOU EVER SEND ME ANOTHER ASSAY ..NO CHARGE...PAUL"

OK, but I still take the rest of the assay with a grain of salt. I'm SURE there is arsenic in shot, the only question is how much.

Where do I go from here? Mostly nowhere. :) I could order more reclaimed shot and hope for the best. :?