RCBS MOULD 7MM-145-SIL problems

[fastcar]

Hi all
I have been lurking for about a year this my first post .
I am have a problem with a new mould I just got a couple weeks ago .
I am getting poorly formed boolits 70056
I have cast about 800 7mm boolits from a seco mould with out this problem .
I am get about 10% good boolits from the mould .
I brought a 200grn .308 mould of the same style at the same time and I am using the same lead mix without this problem.
I am using a lee pot with a PID to control it at 716F (380C)
Thanks Marcus

[Doc Highwall]

Your mould is dirty and needs to be cleaned some more. It is not uncommon for oils to seep out of the pores of the metal with heat.

[caseyboy]

Looks like something is still in the mould. Try scrubbing it out with liquid soap and an old toothbrush. Also a bit of tin may help.

[Von Gruff]

It also looks like there is a mould pre heat or alloy heat deficit.

[mtnman31]

I'd also suggest a good cleaning. Denatured alcohol while the mold is cool. I've had some molds that took a couple good cleanings after they kept dropping bullets that looked exactly like the ones you had pictured. You could also try smoking the mold.

[44man]

I don't know! Looks like bottom pour with lead starting to harden and more poured in. I would turn the heat up a little and get the mold up to temps.

[runfiverun]

yep a little gunk coming out of the bottom pour and a slow stuttering fill.
line the holes up and shoot them full.
it takes a little bit to get the timing right.

[fastcar]

Just got back from another go cast this mould .
These boolits are still coming out of the mould like this after after a preheat on a gas burner and dropping 60 or 80 boolits
I added half a stick of 50/50 solder to the pot this time round and was getting some " whiskers " on some of the boolits.
Probably getting 30% good now , I have had two goes at cleaning the mould with methanol when I got it and another after about 150 boolits , will give that another go when it cools down.
Also has any one got one of these molds it is throwing about 162grns and is supposed to be 145grn it is 1.030 inch long I am wondering if it has been miss marked and packaged?

[caseyboy]

Yup, I have that mould. With WW plus 2% tin, they drop at 144 grains for me.

[PS Paul]

You mention it is a NEW mold. Since you've cleaned it and had some little better success, I would bet you simply need to clean it some more and just use it a few more times. Not only to correctly "season" the moldk but to also find how it likes to be fed, as RUNFIVE suggests.

Despite the fact you've had success with your alloy and temp control in other molds, I've found, just like firearms, each mold is sort of "a law unto itself" and some of them, particularly new ones, just won't throw good boolits until they've been used several times. Others? Cast perfectly first timeout with little seasoning or adjusting to find how it best likes fed.

You're halfway there, dude! Clean it AGAIN and just cast and heat and cast some more. You WILL get 'er up and runnin' correctly soonenough.

I just went through this with an H&G clone and had to cast withit ('twas brand new) five times until it seasoned up, settled in and cast right.
Good luck!

[fastcar]

Ok I just cleaned it again let it dry off in the sun and cleaned it again and had another casting session still not any better than 20-30%.
I agree it may take a few more heat cycles but it has been very frustrating so far.
Caseyboy what length is is your cast bullet from your mould?

[Lefty SRH]

I have similar RCBS molds and they won't run unless my alloy is 750* and after each pour they go and sit on the hot plate. These are great molds but they like the heat!

[cbrick]

That is a fine boolit design, I have fired perfect 80x80 scores in NRA National Championship Long Range matches from a XP-100 in 7br with it. I have never seen any need to crank up the heat with this or any other RCBS mold. The one in the picture was cast from COWW +2% Sn at 700 degrees. Boolit length is 1.00 inch, mine casts this alloy at 147 gr.

70081

I agree with others that the mold isn't clean enough and the mold temp isn't correct. You could also try fluxing your alloy properly using sawdust.

Rick

[Moonie]

That is a fine boolit design, I have fired perfect 80x80 scores in NRA National Championship Long Range matches from a XP-100 in 7br with it. I have never seen any need to crank up the heat with this or any other RCBS mold. The one in the picture was cast from COWW +2% Sn at 700 degrees. Boolit length is 1.00 inch, mine casts this alloy at 147 gr.

70081

I agree with others that the mold isn't clean enough and the mold temp isn't correct. You could also try fluxing your alloy properly using sawdust.

Rick

Rick, your mold pr0n is the best.

[PS Paul]

I too use sawdust as CB Rick mentions. ANYTHING HE SAYS, please pay attention. The man is pretty much "casting genius" and I certainly listen when HE speaks- the truth.

[PS Paul]

That is a fine boolit design, I have fired perfect 80x80 scores in NRA National Championship Long Range matches from a XP-100 in 7br with it. I have never seen any need to crank up the heat with this or any other RCBS mold. The one in the picture was cast from COWW +2% Sn at 700 degrees. Boolit length is 1.00 inch, mine casts this alloy at 147 gr.

70081

I agree with others that the mold isn't clean enough and the mold temp isn't correct. You could also try fluxing your alloy properly using sawdust.

Rick

Hey, man. Your photos of boolits are ALWAYS just about "presentation grade"! Off topic BUT, you have any pointers on anything special you do (diffused light, different light sources, filters, special "colors" like the orange in yer shots) for the rest of us so WE TOO can get really nice pics of OUR boolits??

[whisler]

Forget about the methanol and use dish detergent and water and a toothbrush. Better yet, soak in mineral spirits, then scrub as above. Methanol evaporates too fast for good oil removal unless you are flushing the mold with it.

[cbrick]

:hijack:

I do have a secret for the photos coming out good. I am much too lazy to mess with things like diffused light, different light sources, filters, special "colors".

The first secret is to buy a camera that's smarter than me (not hard), since I am by no means a photographer the camera must know how to take pictures and have a close up setting.

There is no special color used in that picture, it's simply the reflection of the wood shelf the boolit is sitting on.

No special alloy that looks good, as are the vast majority of my boolits it is straight clip-on WW with 2% Sn added, sized with GC & without lube.

So what is the secret? I retired from 34 years in the motion picture/TV industry (not the camera or lighting dept.), the lighting dept. in some cases use light bulbs that can run 20-25 thousand dollars a bulb in an attempt to duplicate the single best light source for a camera there is. The secret is to use that best of all light sources, take your pictures of your favorite boolit outside in full direct sunlight. A clear bright day with no clouds.

That's it, it's that simple. A camera with a close up setting that's smarter than me and a clear bright day. :mrgreen:

Rick

[PS Paul]

You're serious. Never woulda guessed!

thanks, man. I'll give that a try since I DO have a good camera AND we get a few days per year of sunshine up here in Seattle (har har)!

thanks, Rick. It IS appreciated!
Paul

[fastcar]

tried again yesterday , made a few changes .
I tried some other lead I had . It was range pickup that I had melted in a large pot cleaned off all the muck and cast into ingots .
I also cleaned out my pot , there was a lot of carbon in it that I had not noticed before .
And soaked the mold in methanol ( I will try to get a better solvent tomorrow ) gave it a scrub twice more and let dry.
So while the lead was melting I noticed that at 570F the lead was molten , the other lead was like a sludge at this temperature and needed to be up around 660F before it became molten.
7043270433
This is both sides of the same projectile .
they all filled out the mold very well but more than half looked dirty. apart from that some of the best bullets I have cast .
so still one side of the mold dirty ? or maybe need to find a better flux? I have only got bees wax for fluxing , should I stir the pot or let it just sit .
Thanks marcus

[runfiverun]

now you just have oxide inclusions.
stir scrape fire scrape fire

[cbrick]

or maybe need to find a better flux? I have only got bees wax for fluxing, Thanks marcus

From Ingot To Target (http://www.lasc.us/Fryxell_Book_textonly2.pdf)

Read chapter 4 on fluxing and you'll understand what flux is, what you need flux to do and why.

Wax IS NOT flux, wax CANNOT flux. Wax will reduce the tin in your alloy but you need more than that, you need to flux the alloy. I know many published books say to use wax or oil but much has been learned in recent years, just because great grandpa did it that way doesn't mean there isn't a better way, a much better way.

Rick

[randyrat]

Use a wooden stick to scrape the carbon off the sides of your pot. Dip it slow into your molten lead moister will come out of even dry wood.

Since I have been using a wooden stick, my bottom pour never clogs and there's no inclusions.

Scrub the heck out of that mold using a good detergent and an old toothbrush, even after the Methanol cleaning. I use one like Ajax, something that is a little course to aid in lifting off contaminates.
I'm not sure if it is inclusions, Lead temp or or you have some stubborn petro in the mold cavities.

Sawdust is the best for fluxing

[Doc Highwall]

One side of the mould looks good but the other needs more cleaning.

[fastcar]

Ok I have read chapter 4 on fluxing ingot to target . I have cleaned the mold with soap and water .I fluxed with saw dust and used a stick to stir the pot.
They are looking better But I am getting inclusions that I did not have before .
Does it matter what wood the saw dust comes from ? should I be trying to stir the saw dust into the lead?(got splattered with lead trying to do that)

[Three44s]

You said you are using range lead.

That's going to be dirty.

When I reclaim wheel weights .... also dirty ........ I use a plain lead pot .... a large one for faster output and also to get away from trying to clean a bottom pour pot so often.

I run my "dirty" lead twice into ingots and flux both times.

Before I use my bottom pour, I clean it to perfection .... take it all apart and clean everything and anything I can reach!

Now, I run my very clean reclaimed lead ingots into the bottom pour and flux that lead again.

It's very hard to get your lead alloy "too clean".

Also for point of reference, I threw my Marvelux fluxing agent away .... it's a guarenteed pot cruder upper!!! ........

............Who needs that?

I like to use a good metal spoon for the deep scraping while fluxing, use a wooden stick (inserted into the melt very slowly due to trapped moisture and the danger of of the tinsel fairy making an appearance) for the upper portion of the melt and saw dust on top of the molten lead .........

If I don't have the wood materials at hand, I will use bullet lube ......

...... but...... I like the wood stuff the best.

As I learned the value of wood items for stirring/fluxing right here on this forum ..... I layed my spoon aside for a time .... but then a gracious member brought me back to my senses and the spoon is better for the bottom of the lead pot.

The reason is this:

The fine particles from the wooden stir stick and burnt sawdust will not float from the bottom of the melt reliably. The metal spoon sheds nothing if it's clean but it will bring impurities up to a higher level in the molten alloy where you fluxing agent particles will re-surface.

If you get the introduced carbon particles too far down in the pot, you may not get it all back up. That said, it will also likely then end up going out into your mold ..... just where you really don't want it.

You just asked about stirring the sawdust into the melt ......

Here's the rule: What ever you want to submerge in the melt .... had better be pre-heated.

With the saw dust that means that any moisture is burned off by letting it lay on top until you are sure it's "dry" from pre-heating.

Even metal objects carry moisture in their pore spaces. Pre-heat everything!

Pre-heat your ingot molds too!!!

The tinsel fairy is very MEAN!! Don't invite it to your casting session!!

Three 44s

[cbrick]

should I be trying to stir the saw dust into the lead? (got splattered with lead trying to do that)

As for me, I never use a wood stick to stir or scrape, a slotted stainless steel spoon is all I use. I never try to get anything under the surface of the melt, lead is dense enough to hold it there.

From another thread in the alloy section, explains it pretty well.


Actually, you can tell how much to flux if using a true flux like sawdust. When "smelting" scrap, I throw in several handfulls (enough to put about a half-inch layer across the pot) and bring up ladlefulls of lead to drizzle through the charring, smoldering sawdust over and over so as much alloy as possible is directly exposed to the sawdust for purification. The sawdust will "absorb" (oversimplification) certain elements we don't want like aluminum, zinc, iron, calcium, and some others) while leaving the tin and antimony bonded with the lead behind. Allow the sawdust to char mostly to ash, and it will likely be like burned-up aluminum foil. Skim it all and do it again. The ash will be finer and less clumpy. When your sawdust chars to a nice, even black color without the burn-foil clumpiness, most of the impurities that it can remove are gone. Sometimes it only takes once, sometimes three or four cycles of drizzling the alloy through until it's ash, skimming clean, and dumping in more sawdust to get the yuck out. Removing the bad contaminants makes a WORLD of difference to the way an alloy will cast. Gear

[randyrat]

OK........ Use a wooden stick, hard wood last a bit longer. Then use a spoon and see which you like the best.

I think DOC is on the right track.

WOW! Lots of good info here on this thread for you.

[nekshot]

I had a mold that cast boolits just like yours. I simply gave up and turned the heat up all the way, took a qtip soaked in KROIL and swapped the inside and outside of mold and cast frosty boolits for a while (atleast 10 casts) and the mold cleaned up and now casts nice boolits. Hey at this stage any thing is worth a go!

[Doc Highwall]

I get my lead from a indoor range that only allows 22rf. and it is mixed with lots of sand and dirt when I shovel it up from the bottom of the back stop.

I use a 14 qt. Dutch oven to melt this in the first time over a propane burner and flux the hell out of it and pour it into 8" cast iron frying pans I bought at wall world.

First I fill the pot to the top with the raw lead and then start the fire in order to heat it up. When it is 700+ degrees I flux it and stir it several times. The 14 qt. Dutch oven holds approximately 250+ pounds without going over the top edge. I have 4 of the 8” cast iron frying pans and the ingots from them weigh approximately 20 Lbs. each meaning I drain approximately 80 Lbs. of lead out for each pour. This leaves approximately 170+ Lbs. of lead in the 14 qt. Dutch oven, I now refill the pot slowly and put the cover back on the pot while it re-heats up. By this time the lead in the 8” frying pans have cooled enough to empty and I keep repeating till I run out of lead.

Now that I have several stacks of 8” ingots that will fit into a 8 qt. Dutch oven I am ready to re-melt and re-flux before alloying the lead. The first thing I do is weigh what 4 or 5 of the ingots weigh and add their weight up knowing that they will fit into the 8 qt. Dutch oven. I place them into the Dutch oven and start the fire, when they get up to 700+ degrees I again flux and re-flux several times. While waiting for the lead to melt I weigh out the material I am going to alloy with it so it will be ready.

I now pour this alloy into different shaped ingots that identify what it’s contents are by shape, and still able to fit into my LEE pot with a PID unit I bought from Frozone a member here.

Using this procedure means I have had fluxed my alloy two different times to clean it, before it even goes into the LEE pot for casting bullets helping insure a clean alloy and bullets without inclusions.

When I smelt I am wearing all natural materials like cotton and leather that only burn if hot lead spatters on them, unlike synthetics that melt and burn. I have a ball cap on backwards with a full face shield and a leather welding apron, while wearing a long sleeve shirt with the collar up and heavy leather gloves that go up to my elbows.

This is the time most likely that the tinsel fairy will visit, so I take the most precautions at this time.

I preheat the ingots on a hot plate with the mould/moulds at 300-325 degrees which is above the boiling point of water, so the danger of the tinsel fairy visiting when I replenish the LEE pot with new alloy is highly unlikely.

Because I only put clean alloy into my LEE pot contamination is kept to a minimum, and having the right shaped scrapers for the pot helps in getting contaminates to the top with fluxing and removing them.

The biggest problem I have now is, insuring that the mould is clean and free of burrs in order to get good bullets.

[Larry Gibson]

Range lead usually has antimony but little tin.......suggest you add 2% tin and then flux real well. Cast with the alloy at 725 - 730. Might want to add 20% lead also. I've used "range lead" (lots of jacketed and commercail cast handgun bullets and .22LR bullets) over the years from several different ranges. Adding the tin, and about half the time, the lead make it into a very good alloy useful for most all handgun and low end rifle cast bullet loads. When WQ'd the BHN is often in the 16 - 20 range and it then makes very good rifle cast bullets for 1800 - 2100 fps shooting. BTW; numerous batches of range lead I've used did just what yours is doing; adding the tin and lead and then fluxing real well always cured the problem and gave excellent cast bullets.

Larry Gibson

[Smoke4320]

Many people here have been doing this much longer than me but hete are my suggestions .
use sawdust as a flux . I use cedar dog bedding chips . A Pinch between three fingers and crush.
Works and smells good too