Media question

[TSO]

Looks like I will update my mill this winter and use my 3lb rubber barrells for single chems with alumina media from Pyrocreations. For those who have gone this route how much/many alumina barrel shaped media in a three lb barrel? Steve's website claims that 20 13/16" and 20 1/2" is perfect, but that seems pretty light on the media, 40 13/16" and 40 1/2" alumina seems more appropriate to me in a 3lb rubber barrel.

Edited October 16, 2014 by TSO

[dagabu]

A good ball mill will have 1/2 of the jar full of media, use an online calculator to determine your jar and the amount of balls to fill it 1/2 way.

[schroedinger]

For a Lortone 3 lb you will need about 700g of 20 mm or 900g of 10 mm.

Better use the smaler media exept for big chunky things then use the bigger media.

[Mumbles]

I would agree that 20 of each sounds pretty light. It takes about 200 1/2" lead balls to fill one of these jars. The cylindrical shape of the ceramic media they have should pack differently, but maybe 150ish? Taking into consideration two different sizes of media is not something I'm really qualified to speak on. On a pure weight argument, it takes about 12-15lbs of alumina ceramic to fill a 1 gallon jar. This one is about 1/5 the size of that, so it should take approximately 2.5-3lbs of ceramic. I find weight to be a fairly good measure, as opposed to direct count, and somewhat takes geometry and size out of the equation. Pyrocreations lists 2 different masses for 50 alumina cylinders (1.1lb and .61lb), so I have no idea which is real. At 1.1lbs, that'd be about 125ish, so it seems reasonable to me. The 20/20 mix pack weighs 1.6lbs, so I'd say two sets, or 40 of each, is in the right ball park.

 

Personally, I would think that 13/16" media would be too large for this size of mill, but I doubt they'd recommend it if they got regular complaints.

[Bobosan]

The 1/2" alumina I have here from Pyrocreations weighs 1lb,6 oz per 100 pieces. It takes 150 pieces to fill a HF rubber jar half full. Total weight of media in a jar with no lid is 3 lbs +/- 1oz.

Edited October 16, 2014 by Bobosan

[TSO]

_{The 1/2" alumina I have here from Pyrocreations weighs 1lb,6 oz per 100 pieces. It takes 150 pieces to fill a HF rubber jar half full. Total weight of media in a jar with no lid is 3 lbs +/- 1oz.}

 

 

Thank you very much sir!

The 1/2 alumina barrels work fine for you for grinding? I had planned on doing the mix of sizes, but the 13/16" did seem a bit large for the jars as Mumbles mentioned,

[Bobosan]

The 13/16 is too large for the HF rubber jar. Per Lloyd Sponenburgh, all media should be the same size for maximum milling efficiency. The 1/2 works great for milling smaller quantities of chems in HF barrels.

[enanthate]

Im currently using 13mm alumina media, but just ordered 17mm lead. The alumina is OK, but takes alot of milling time, and your chems should be quite fine already.

 

Just got some Pine charcoal that is everything from 10mesh to airfloat. Alumina media doesn't break all the pieces, leaving alot of coarse charcoal. This is never a great idea, specially not when using the charcoal for rolling/priming etc, as you will have a bunch of coarse charcoal left in the bucket that doesn't stick to the stars/etc.

 

My jar is loaded 3/4 with media and 100g powders.

 

The point Im trying to make is, get lead when you're already going to order something. You will probably get it eventually anyway.

Edited October 20, 2014 by enanthate

[Sparx88]

I'm using 115 .60 5% antimony lead in my 3 lb jars. They break down all but uncooked wood. Just an option, maybe not the best for everyone. I bought a small cast iron pot and a Lee double .60 ball mold and made them melting down hardcast lead buckshot. I feel lead is ideal.

[MrB]

I just wish higher antimony content was easy to come by over here. Nowadays you cant even get lead wheel weights, I had to resort to buying pre-alloyed bullet casting lead which has a disappointing hardness, at 5% Antimony, even if "water-quenched".

It doesn't affect milling in any noticeable way, but it does make you recast your media more often. Which is boring. I went and bought a couple of ball sinker molds, and modded them with handles, and tweaked the way they fit together, so now i at least can make 8 12mm or 7 15mm balls at the time... The drawback is i need to cut them apart instead. *sigh* cant get everything, i guess.

B!

[enanthate]

I've milled a few kilograms of BP so far, all using commercial willow. Today I tried my first batch with some homemade pine that I got from ebay. WOW. 2 hours of this stuff in the mill beats 4hours of willow easily. This BP is HOT! 2 hours with alumina round balls.

 

I'm saying this because before being concerned with milling media, get your right charcoal. This is far more important!

 

Didn't realize how big the difference is until today, this little piece of information can't be repeated enough.

[Bobosan]

I'm using 115 .60 5% antimony lead in my 3 lb jars. They break down all but uncooked wood. Just an option, maybe not the best for everyone. I bought a small cast iron pot and a Lee double .60 ball mold and made them melting down hardcast lead buckshot. I feel lead is ideal.

 

Sparx, where did you get the double 0.600? Haven't found a reasonable source for a double. Got my single Lee 0.600 mold off ebay.

[Sparx88]

I got mine off ebay last xmas. I don't have the info you would need as it was the only listing for it. It's not there anymore I was looking sorry. Seems they have every other size under the sun though lol. Heres a pic I just took of it.

 

 

edit, Looks like Lee has them at the website for 25.95 with handles. I think thats about what I paid for mine.

Edited October 21, 2014 by Sparx88

[eekAmouse]

Bobosan,

You can also check the swapin&sellin section over at castboolits.com

[Bobosan]

Thanks eek. I'll check out that forum section.

[Sparx88]

oops, sorry meant to edit and doubled up.

Edited October 22, 2014 by Sparx88

[Sparx88]

I just wish higher antimony content was easy to come by over here. Nowadays you cant even get lead wheel weights, I had to resort to buying pre-alloyed bullet casting lead which has a disappointing hardness, at 5% Antimony, even if "water-quenched".

It doesn't affect milling in any noticeable way, but it does make you recast your media more often. Which is boring. I went and bought a couple of ball sinker molds, and modded them with handles, and tweaked the way they fit together, so now i at least can make 8 12mm or 7 15mm balls at the time... The drawback is i need to cut them apart instead. *sigh* cant get everything, i guess.

B!

 

Same here bud. Just gotta use what you can get. I reload 12 gauge so hardcast buckshot was really easy for me to choose. So far after maybe 160 hrs of milling various things even aluminum no need for recasting yet. Though I'm no expert in what degree of wear mandates re casting. Here's some before and after pics. I use these in some of my reloads for those buckhammer moments. Looks to be about .037 wear, is that bad?

 

 

edit- the more I think about it theres more than 160 hrs on those. The aluminum sessions were between 36 and 48 hrs each x 3. So maybe more like 250 hrs. I don't keep a log of this stuff, just a ballpark guess.

Edited October 22, 2014 by Sparx88

[Bobosan]

Chunky charcoal will wear media quickly so I imagine aluminum would be just as abrasive. I have separate media for charcoal and BP and the BP lead has only lost 0.002-0.003.

 

Two sets of lead mill media, one for BP only using premilled chems and one for charcoal only. The media is cast 0.600-0.602 diameter, wheelweight 75% linotype 25% and water quenched. After many hours of BP milling, the BP lead media is 0.598-0.600 and the charcoal media is 0.589-0.591. Note the smooth surface of the charcoal media which is worn the most. The only charcoal milled has been Paulownia and Willow with Willow being the harder.

Edited October 22, 2014 by Bobosan

[Sparx88]

Ya see all my stuff isn't pre milled and I use pauls and pine from out back . The charcoal is chunky as i break it in a freezer bag then into the mill jar for servicing. Then it's mixed with the rest and milled further. The aluminum starts out as 1/8" bits and milled to about firefly is all. It's amazing that charcoal can do that compared to salts.

[Bobosan]

Bobosan,

You can also check the swapin&sellin section over at castboolits.com

 

Just found and bought one from Midway. Last time I looked they didn't have a double cavity. $22.00 including shipping and NRA roundup.

[enanthate]

I purchased lead media from cooperman yesterday, it doesn't say it's antimony so I assume it's not. Do these balls get worn quickly?

I'm asking because I won't be able to recast them. Should I order more right away?

edit: These balls will be used ~25hours before new years eve I recon, so not alot.

Edited October 22, 2014 by enanthate

[Sparx88]

Maybe about as quickly as mine do since mine are about as close to pure lead as you get with anything containing antimony. Yes there is better to be had but under the circumstances theres nothing wrong with what you have on the way. You can use these till they shed a cal or 2 like if they are .50 cal you can use them until they are .30 cal in reality. If by then you could have a chance to purchase something better or get a mold and recast when needed. The amount of lead given off is so little it's not a concern in the hobby pyro that we do.

[enanthate]

Thanks, sounds like I'll be fine then. They are 17mm, and my mill is 3lb. so I would actually prefer they go a bit smaller in size

[Shadowcat1969]

Actually the .50 cal works great in the 3 lb mill. It also shouldn't shed that much in only 25 hours of milling, mine lasted well over that and I was just using muzzleloading balls originally.

[enanthate]

.50 cal is about 12mm, mine is 17. It is supposed to be a bit too big from what I've read, but I'm sure its gonna do just fine. My alumina already mills HOT bp in 2 hours so it shouldnt be a problem Those are 12mm though, hopefully it isn't too much of a difference. We'll see.

Edited October 23, 2014 by enanthate