cast boolit flaws due to shrinkage: announcing the solution (for me anyway).

[JonB_in_Glencoe]

Old photo, that I posted in cast pic of the month back in 2013.
http://castboolits.gunloads.com/showthread.php?187202-March-2013-Photo-Submission-*Topic-Cast-Boolit-Imperfections

http://i640.photobucket.com/albums/uu127/JonB_in_Glencoe/boolitsShrinkageflaws_zps195192dd.jpg

OK, I've been casting for 4 years.

As like many of us newbies, I am continually seeking to improve my technique. One issue I have had, mostly with long rifle boolits, is shrinkage. A few different examples of such are shown above.

I've asked questions about this, at least a couple times since I started casting. I've tried the suggested answers and while they may have been good ones, they weren't my solution.

For me, this shrinkage issue was about as random as it gets. sometimes it seemed like it was one particular cavity of a mold...so I'd try changing the order that I'd pour the cavities, many times it helped, but the shrinkage issues would always return sooner or later.

I tried different alloy formulations...more Tin, then Less Tin. Once in a while the problem seemed to get solved...only to show up in the next casting session ???

I obviously tried different alloy temperatures and casting faster (to raise the mold temperature) as well as casting slower and using a fan to cast with a cooler mold and getting shiny boolits. It seems each time I'd make a change and go with it, the problem would go away...only to show up after I'd get into a rhythm ...as soon as I'd get comfortable, the shrinkage issues would pop up and get more frequent.

I think I found the solution last summer. If you clicked on the link at the top of this post and scrolled down to #8 to see my March 2013 photo submission, you'll see I edited the text in August 2014 with what I figured out this summer.

I wanted to make a grand post like this back then, but I thought I solved this problem so many times before, I was hesitant, for fear I was wrong again.

So now with several successful rifle boolit casting sessions under my belt, I am comfortable announcing the solution to my problem.

The Solution:
Pouring as large of a sprue puddle as reasonably possible.

My problem I had to overcome to resolve this:
I'm sure I've read about pouring a large sprue and I'm sure I've been told that as well, when I asked about shrinkage in the past. But what it always came down to is...when I'd get into a comfortable pouring rhythm, I pour a smaller and smaller sprue...so as to reduce the amount of alloy usage per pour which should yield more boolits per pot of alloy. I needed to reprogram my brain. More perfect boolits per pot is better than just more boolits per pot.

The Photo below showns my most recent casting session using the NOE 358009, these have not yet been sorted, you may see a couple flaws here and there. NOW, if I have poured small sprue puddles as I did a year ago, more than half would have to be culled.

That mold WAS probably my most troublesome when it came to shrinkage...I suppose it's ratio of length to width, is the greatest of all of the boolits I cast, which would probably exacerbate shrinkage from a small sprue puddle.

I just thought I'd share this, because it took me soooo long to figure it out, even though the solution was always close at hand.
Good Luck,
Jon

http://i640.photobucket.com/albums/uu127/JonB_in_Glencoe/closeup_zps6e12e9d4.jpg (http://s640.photobucket.com/user/JonB_in_Glencoe/media/closeup_zps6e12e9d4.jpg.html)

[RED333]

The faster ya go the be hinder ya get.
This works for a lot of stuff I do, but never thought about it and casting.
Thanks for the info, just helped me a lot.

[44man]

Bottom pour needs a large sprue for sure.
I ladle cast and hold the ladle on long enough for the boolit to take all the lead it needs from molten lead so I can go with a small sprue.
I am so glad you figured it out and you have a fine bunch now.

[**oneshot**]

Once you find what works for a particular mold. Post it above your casting pot so you know for next time. I have some molds that like one thing or another for best results and keep a poster board with notes at my casting station. Temp, pace, pour method, all good things to write down for next time, especially if you use many molds.

[popper]

IMHO, the idea behind a large sprue is to keep the sprue (reservoir) hot enough to flow into the cavity. Your lower left boolit is interesting because it appears the body is frosty & the base is NOT. Upper left is cold mould. Lower right has bad shank fillout but the rest looks good. I think you also get cleaner alloy as you learned. Too large a sprue will possibly stop proper venting. Maybe the better mould helped also.

[JonB_in_Glencoe]

IMHO, the idea behind a large sprue is to keep the sprue (reservoir) hot enough to flow into the cavity. Your lower left boolit is interesting because it appears the body is frosty & the base is NOT. Upper left is cold mould. Lower right has bad shank fillout but the rest looks good. I think you also get cleaner alloy as you learned. Too large a sprue will possibly stop proper venting. Maybe the better mould helped also.
Popper,
Are you implying that a Large, as possible, sprue puddle is not my solution to long rifle boolit shrinkage problem ?

The photo was taken for a cast pic of the month contest...to show a variety of shrinkages... it was taken 18 months ago, I haven't photographed any other shrinkage issue boolits and that old photo with varied boolits doesn't necessarily convey commonality of the shrinkage I had. Although, I guess I can say the upper right boolit's shrinkage, at mid point (on the bore ride section just above, and including, the top driving band), is representative of the vast majority of the culls I experienced.

BTW, mold quality didn't help...Maybe I didn't convey it clearly enough, The NOE 358009 mold was the worst offender of shrinkage...til I started pouring large as possible Sprue puddles.

I am curious about your comments about cleaner alloy and "too large a sprue will possibly stop proper venting".
How will either of those effect shrinkage ?
and how will that stop proper venting ?

Thanks for the input,
Jon

[JSnover]

I'm not convinced that a large sprue can interfere with venting, since it sits on top of the sprue plate. Venting occurs between the blocks, down along the length of the cavity, through the vent lines.

[John Boy]

Alloy fill out is simple: ladle pour > spout in sprue hole > 5 seconds pour > pot melt & mold same temperature so sprue puddle frosts in 5 seconds and keep a good rhythm. Has worked for me for many years with bullet weights in a 0.05gr Bell Curve. And I cast small and large bullets for long range BPCR shooting the same way

[cbrick]

I always recommend as large a sprue as possible, when ladle casting I not only pour a large sprue I let it keep running right over the side of the mold back into the pot. I don't look at it as pouring lead but rather pouring heat. Can be the cure for several ills and go a long way to quality bullets.

Since it's been since last summer that you've experienced the "shrinkage" I would say that your doing it just right. :mrgreen:

Rick

[btroj]

I knew Rick would throw the ladle in there. I got one after he nagged me like an old woman, he was right.

I don't pour large sprues but I do pour lots from the ladle for a few seconds after each cavity is full. Lots of heat makes a difference.

[Bjornb]

Allow me to post a little experiment i did yesterday while casting. I had about 17 lbs. of 92-4-4 alloy made from certified metals, and I am (was) a firm believer in the superiority of ladle casting. I knew, however, that after about 250 bullets or so, the large Rowell ladle would not be able to scoop up sufficient alloy from the Lee pot, and I planned to switch to bottom pour.
My plan was then to cull and weight sort the bullets from the 2 sessions and compare the 2 bell curves to determine which casting method was the better.

First casting setup:
120860
Second setup:
120861

Now I was convinced that the ladle poured bullets would be more consistent, since the ladle gets a larger, stronger stream of lead into the cavities in a shorter period of time. This did not happen.

Ladle poured bullets:
120865
Not exactly a bell curve to brag about.

Bottom poured bullets:
120866
Disclosure: I have opened the pour spout on my Drip-O-Matic from 1/16 to 3/32 to get a stronger stream of lead.

OK, so I thought that I had discovered something great here, like an "Earth-is-round" thing.

HOWEVER, the more I thought about it, the more one thing started sticking out in my mind:
When ladle pouring with my HEAVY brass 4-banger mould I would rest the mould on the edge of the pot while pouring.

What does that have to do with anything? It angles the mould down (if I didn't angle the mould into the pot the 2-lbs. Rowell ladle would pour lead everywhere), and there was never a consistent SPRUE on the sprue plate. Pouring with the Lee B.P. on the other hand, as you can see in the picture, a healthy sprue was poured every time, making for a more consistent quality. Cull ratio (visual defects) was the same for both pours, right on 10%.

So, in conclusion there is no conclusion. My 2 pouring sessions showed what 2 different techniques will produce, but it wasn't apples to apples.
Goodsteel is lending me his 2-cav NOE XCB mould so I can repeat the test with the mould fully hanging inside the rim of the pot so I can leave a sprue while pouring with the ladle. We shall see.

[cbrick]

The smaller pot would make it more difficult. I recommended the Rowell #2 to btroj & I think he uses an RCBS pot. A month or so ago I was at winelovers place and did some casting with my Rowell #2 and his RCBS pot & got a good reminder, the smaller pot took some getting used to. Made me appreciate my Magma though.

I think the healthier sprue is a benefit, been recommending it for a long time, some listen some don't.

Rick

[btroj]

I am seriously considering a Magma 40 pounder. I have a #2 Rowell, I listened Rick, and it is awesome.
I did learn that pouring into the cavity for a period after it is full makes a difference. The base quality suffers if I fill and move on. Fill, keep pouring, then move to the next cavity.

[RobS]

Yep..........sprue plate is too cool and the drive bands don't fill out before the alloy near the sprue plate (base of the boolit) solidifies. A mold that doesn't vent well makes this situation even worse.

[stephen m weiss]

A large sprue puddle creates pressure to fill the cavity, and more hot lead toward the center. What I dont understand is why sprue plates are so darn thin on deep molds. Common parts is a great idea, when they work. But, deep molds need higher pressure. So do smaller diameter molds. What's so wrong with a thicker sprue plate to increase pressure? I drill mine out to increase flow rate, which helps, but cutting the sprue is then harder as well. It frustrates me that mold builders do not address this basic issue we learned in high school casting, like 40 years ago. Molds that do not work does NOT help their business.

[35 shooter]

JonB Thanks! This was a timely post for me as i realized i've been doing this very thing lately...as in pouring a smaller sprue. Today i kept the sprues thick and had no rejects as far as fill out. I just thought the lack of fill out was just the mould getting too hot, but evidentally not, as i had no problems today. This was a good reminder for me...Thanks again!

[cbrick]

What's so wrong with a thicker sprue plate to increase pressure? I drill mine out to increase flow rate, which helps, but cutting the sprue is then harder as well. It frustrates me that mold builders do not address this basic issue

Do have any NOE or MP molds?

Rick

[williamwaco]

Try this experiment.

Pour a very small sprue. Only enough to fill the vent. not enough to make a puddle.
Watch what happens.

You will actually see the lead from the small sprue flowing into the mold through the hole.

In some cases, the flow into the mold will leave a small hole in the sprue and when you cut it off, the hole will continue into the base of the bullet. Alloy will absolutely flow into the mold from the sprue. IF: the metal hot enough to flow as the bullet shrinks.

[Jack Stanley]

Thanks Jon , that explains why my LBT moulds don't have that problem and some of my other moulds do .

Jack

[Calamity Jake]

As you've found, pouring a large spru is important for fill out, but looking at the voids on the
2 boolits on the left and center, makes me believe they are air pockets, not a spru size
problem per-say.
If you will notice that all the voids are no where near the parting lines meaning that the air
was trapped and could not get out.
I have always poured a large spru but on occasion have had the voids shown in your photo,
my cure was to watch what side of the mold it happened on and tilt the mold slightly
in that direction to help remove the air.

[nemesisenforcer]

Good advice. Will try it next time I cast. I bottom pour so my run off doesn't go back in the pot so it can make a mess but I'll work around it.

[cbrick]

Ya don't have to make a mess bottom pouring but should pour as generous a sprue puddle as you can.

Rick

[btroj]

I was a dedicated bottom pour guy until Rick convinced me to get a Rowell ladle. No more bottom pour for me.

Try one, your won't be disappointed.

[leftiye]

It's about mold temp. The mold must cool from the outside inwards (if you think about it, anything else is impossible), and from bottom to top (the important part). So, the top of the mold must be hot enough that the lead there cools last. Otherwise, the boolit won't be able to draw from the sprue. This is why borderline frosty molds fill out as well as they do. If the top of the mold or the sprue freezes first, there will be voids, or the boolit will collapse if it is hot enough to bend due to vacuum. The large sprue heats the top of the mold, allowing lower overall mold temp to work correctly (without frosting). A mold temp overall that allows an extended cooling time (relatively) for the sprue is what you should look for. I will put my customary plug in here for using an enclosed mold heater to keep the whole mold hot.

[44man]

The Rowell ladle is like bottom pour, need a good sprue and with some molds, a lot of over run. Rick says it well, pour HEAT! I personally don't like them and use a Lyman ladle.
By keeping a tight fit to the plate and tipping up, you can see lead stop going into the mold, then start to flow in again. You must hold long enough for the mold to take more molten lead out of the ladle. THAT is the secret to ladle pouring. I get almost no shrinkage of the sprues, no depressions by a boolit trying to pull sprue metal.
A six cavity would be hard to do my way but I can use two, two cavity molds at one time.

[popper]

"too large a sprue will possibly stop proper venting".
How will either of those effect shrinkage ?
and how will that stop proper venting ?
Had to 'break the top edge of Lee moulds to get proper venting. Large sprue has weight and can force the plate hard against the top of the blocks, stopping venting - the top does vent! Dirty alloy will cause pits like your first pic and is hard to get out of the bottom pour. All the boolits from the NOE are frosty which isn't bad as long as the mould doesn't get too hot.
Last mould I got leaves frost in the middle but not on the base or nose. Long boolit in a short mould block? Looses heat faster at top & bottom?
edit: poured a bunch of 145s for the BO this morning. Sprue plate has the channel (2x), was getting a lot of BAD rejects. I watched the fill and saw lead pushed by AIR back up the hole. Several with no real base. Moved the bottom pour shelf up 1/4" and poured each cavity by itself ( also cranked the PID up by 10F). Few rejects after that. These are for BO PB test so my culling is very critical. Plan to do another batch in the morning. Probably need to order a standard plate from Tom.

[snuffy]

Jon, your terminology is off a bit. I don't see shrinkage, I see poor fill-out. Most likely a cold mold, or not enough tin in the alloy. What is the alloy?

I agree with the ladle comments, but the rowel ladle is just another way to dribble lead onto a sprue plate. Most ladlers use the overflow method to over-fill the cavities by letting the lead spill off the tops of the mold. The Lyman type allow you to use the "tit" on the bottom to seal the ladle to the sprue hole taper, putting the full weight of the lead in the ladle to act to guarantee fill-out. Holding the ladle in contact with the sprue plate for a 5 count allows the cavity to draw all it needs, you can then pull away to make a small sprue puddle.

The rowel ladle works as well, but with some molds, it would be a problem to over-fill the sprue plate. For instance the cramer type hollow point molds, the pins would be covered with the spillage. Prying the lead off those could take a while!:mad:

I quit the bottom pour method for most rifle molds, just couldn't get fill-out. Lyman bottom pour ladle to the rescue. I call it pressure casting. With the lee 20 pounder, it's darn hard to hold a mold tight up against the nozzle, 20 pounds of lead has too much pressure.

Pistol boolits are fine with bottom pour, the short fat form fills easily with a straight shot from the nozzle.

[cbrick]

Jon, your terminology is off a bit. I don't see shrinkage, I see poor fill-out. Most likely a cold mold, or not enough tin in the alloy. What is the alloy?

I agree with the ladle comments, but the rowel ladle is just another way to dribble lead onto a sprue plate. Most ladlers use the overflow method to over-fill the cavities by letting the lead spill off the tops of the mold. The Lyman type allow you to use the "tit" on the bottom to seal the ladle to the sprue hole taper, putting the full weight of the lead in the ladle to act to guarantee fill-out. Holding the ladle in contact with the sprue plate for a 5 count allows the cavity to draw all it needs, you can then pull away to make a small sprue puddle.

The rowel ladle works as well, but with some molds, it would be a problem to over-fill the sprue plate. For instance the cramer type hollow point molds, the pins would be covered with the spillage. Prying the lead off those could take a while!

I quit the bottom pour method for most rifle molds, just couldn't get fill-out. Lyman bottom pour ladle to the rescue. I call it pressure casting. With the lee 20 pounder, it's darn hard to hold a mold tight up against the nozzle, 20 pounds of lead has too much pressure.

Pistol boolits are fine with bottom pour, the short fat form fills easily with a straight shot from the nozzle.

Gotta disagree with ya on the Rowell snuffy. The reason for overflowing the sprue plate is to pour heat while giving the bullet base the alloy it needs. Proper casting does not require pressure casting whether ladle casting or bottom pouring. The very last thing I do is . . . "dribble lead on the sprue plate". I routinely use both MP and Hollow Point Molds Cramer style with this method with no issues. Both pistol AND rifle bullets cast perfectly with the Rowell.

Not saying your wrong for you. If your methods work for you then your certainly doing right for you. On the other hand it doesn't mean other methods are wrong just because your not doing it that way nor does it mean the Rowell ladle dibbles lead.

Rick

[243winxb]

Sprue plate hole diameter to small. Enlarge it.

[44man]

I do not believe in "pressure casting" since molten lead is a liquid that will not compress. I believe in feeding molten lead as the boolit shrinks. A sprue can set up and freeze before a boolit in a hot mold. Keep the sprue molten and the boolit can draw so keep pouring or make a large sprue.
I fill my Lyman ladle, pour one boolit, wait until the sprue sets and the pour the second with what is left in the ladle with no difference at all. Why are both boolits the same with half the lead in the ladle for the second? It sure isn't pressure!

[captaint]

On one occasion I was having trouble getting 9mm boolits to fill out the base. I had my harder alloy in the dippin pot, so I used the RCBS ladle which has always been trouble free. Now and then I would get perfect bases and it really puzzled me. Why ?? Turned out it was the ladle resting on the sprue plate. If I didn't hold the ladle above the sprue plate, the venting was not adequate - rounded bases. Keep the ladle off the plate and it could then float up just a little - enough to give me great fillout on the bases. I had broke the edges on top of the mold too. I wish all mold makers would cut the top of their molds a la Veral Smith. Now that works.... Just my experience. Mike

[geargnasher]

Large sprue puddle or contact pouring with a ladle accomplish the same thing: Keeping a molten supply of gravity-fed alloy available to the bullet cavity until the bullet has solidified. I use a bottom-pour almost exclusively and have no issue pouring an eighth-inch thick or thicker sprue puddle, even with Lee six-bangers I get a solid ingot almost as wide as the plate for a sprue. Of course I probably use less tin than most of you so the surface tension of the alloy is higher. Gotta balance that puddle and not let it fall off the plate or run into the next hole while pouring the sequence of cavities.

Gear

[243winxb]

Look like very frosted bullets to me. http://i640.photobucket.com/albums/uu127/JonB_in_Glencoe/closeup_zps6e12e9d4.jpg Sprue plate hole diameter to small. Enlarge it.

[44man]

Sprue plates are a pain. I had many that I could see light under so I lapped them. Doesn't work no matter what you do since edges always cut more then in the middle. You will have a rocker. When I started making my own molds and plates I found to leave mill marks on the mold top and mill the plate, leaving those marks too. When I milled a lapped plate I could see the cutter touching the center more so now if a plate is not flat, I mill it.
I also break the edges for venting but the mill marks also vent very well. End mill cuts make great vents. I also found I only needed to vent one block-.002" deep using a "V" cutter I swing by hand with a fly cutter. I advance .025" for each line.
My molds are crude compared to customs since all I have is a Smithy, lathe, mill, drill. But it has been a learning experience about how a mold works, bar none.
A tribute to the wonderful mold makers but maybe the dead smooth sprue plates or ones too thin should be looked at.

[Cap'n Morgan]

I believe the shrinkage in a boolit more or less happens in multiple stages. The first stage is when the lead goes from molten to solid state, and the shrinkage will be high, somewhere between 5-7% depending on the temperature of the molten lead - the higher the temp. the higher the shrinkage. The second stage takes place in the solidifying temp. zone and is typical between 0.5 to 0.9% depending on the alloy. The third stage is when the boolit cools from AWW! &%¤#HOT!! to room temperature and the shrinkage here is quite small, about 0.1%

Now, 5-7% shrinkage may sound like much - and it is! But since it is an continuous process from the second the molten lead comes in contact with the mold, most of the shrinkage compensation will happen during the filling of the cavity. This is probably why a slow fill often will produce the most uniform boolits. Still, the base of the boolit must have a resevoir of molten lead (the sprue) to draw from right up till it enters the solid state or a cavity will form - often it will just look like a small pin prick in the base, but if you probe it with a needle you'll find a larger cavity below.

[cbrick]

I think the biggest problem most people have with sprue plates is not getting/keeping them hot enough. Sprue plates don't have the mass of the mold blocks plus they spend a fair amount of time sticking out in the air, they loose heat quickly. Pour a generous sprue puddle not to have a nice large sprue but because you are pouring heat. Casting with a cool sprue plate can be nearly as problematic as casting with a HP spud that is too cool or the mold too cool.

Pour heat!

Rick

[44man]

I think the biggest problem most people have with sprue plates is not getting/keeping them hot enough. Sprue plates don't have the mass of the mold blocks plus they spend a fair amount of time sticking out in the air, they loose heat quickly. Pour a generous sprue puddle not to have a nice large sprue but because you are pouring heat. Casting with a cool sprue plate can be nearly as problematic as casting with a HP spud that is too cool or the mold too cool.

Pour heat!

Rick
100% correct. Nothing worse then a sprue setting before a boolit hardens.

[popper]

run into the next hole while pouring the sequence of cavities. Else you get those gnarly wrinkles. Broke the top edge of the 31-142C this morning with the edge of a box knife ( just 'draw' the blade across the edge). Obvious reject rate went WAY down, 20 from 200+ poured. My 'perfection' cull went from ~40% (yesterday) to ~10%. Now to order the standard sprue plate - channeled one doesn't work for me.

[Just Duke]

Allow me to post a little experiment i did yesterday while casting. I had about 17 lbs. of 92-4-4 alloy made from certified metals, and I am (was) a firm believer in the superiority of ladle casting. I knew, however, that after about 250 bullets or so, the large Rowell ladle would not be able to scoop up sufficient alloy from the Lee pot, and I planned to switch to bottom pour.
My plan was then to cull and weight sort the bullets from the 2 sessions and compare the 2 bell curves to determine which casting method was the better.

First casting setup:
120860
Second setup:
120861

Now I was convinced that the ladle poured bullets would be more consistent, since the ladle gets a larger, stronger stream of lead into the cavities in a shorter period of time. This did not happen.

Ladle poured bullets:
120865
Not exactly a bell curve to brag about.

Bottom poured bullets:
120866
Disclosure: I have opened the pour spout on my Drip-O-Matic from 1/16 to 3/32 to get a stronger stream of lead.

OK, so I thought that I had discovered something great here, like an "Earth-is-round" thing.

HOWEVER, the more I thought about it, the more one thing started sticking out in my mind:
When ladle pouring with my HEAVY brass 4-banger mould I would rest the mould on the edge of the pot while pouring.

What does that have to do with anything? It angles the mould down (if I didn't angle the mould into the pot the 2-lbs. Rowell ladle would pour lead everywhere), and there was never a consistent SPRUE on the sprue plate. Pouring with the Lee B.P. on the other hand, as you can see in the picture, a healthy sprue was poured every time, making for a more consistent quality. Cull ratio (visual defects) was the same for both pours, right on 10%.

So, in conclusion there is no conclusion. My 2 pouring sessions showed what 2 different techniques will produce, but it wasn't apples to apples.
Goodsteel is lending me his 2-cav NOE XCB mould so I can repeat the test with the mould fully hanging inside the rim of the pot so I can leave a sprue while pouring with the ladle. We shall see.



Bjorn, I sent you a PM sir. Did you get it?

[JonB_in_Glencoe]

Look like very frosted bullets to me.

Sprue plate hole diameter to small. Enlarge it.

IMHO, they are completely frosted, but not over frosted. The photo was taken at my casting bench, right in front of a east facing window...lots of direct sunlight and the reflections can make for a washed out photo. If you look at the engraving on the mold, is it also washed out, kind of soft and fuzzy looking? ...I can tell you, this NOE mold as well as my others have nice crisp engraving. Bottom line, the boolits look more frosted in that photo, then they actually are. These were cast with a small fan blowing on the drop area and cast at a cadence so the sprue freezes at 4 to 6 seconds from when the galena stream stops. If I were to slow up a little, I get a boolit with a frosty middle and shiney ends and I've found those to not be as consistent as when they are completely frosted.

OK Why do you think my sprue plate hole diameter is too small ?
And what will I achieve by enlarging it ?

[cbrick]

OK Why do you think my sprue plate hole diameter is too small ?
And what will I achieve by enlarging it ?

IMHO not much as long as you keep the sprue plate hot enough.

Rick

[btroj]

I am with Rick. Keep the plate hot and the easiest way to do that is with a large ladle pouring hot lead over the plate.

[243winxb]

OK Why do you think my sprue plate hole diameter is too small ?
And what will I achieve by enlarging it ?
Faster fill. I also enlarged the hole on the Lee 10 lb bottom pour when i had the same problems. Different mould.

[snuffy]

Large sprue puddle or contact pouring with a ladle accomplish the same thing: Keeping a molten supply of gravity-fed alloy available to the bullet cavity until the bullet has solidified. I use a bottom-pour almost exclusively and have no issue pouring an eighth-inch thick or thicker sprue puddle, even with Lee six-bangers I get a solid ingot almost as wide as the plate for a sprue. Of course I probably use less tin than most of you so the surface tension of the alloy is higher. Gotta balance that puddle and not let it fall off the plate or run into the next hole while pouring the sequence of cavities.

Gear

Gear to the rescue--again. " gravity-fed alloy" is what I was attempting to say, pressure casting was a poor choice of words.

Rick, again my lack of english training causes poor conveyance of my meaning. Dribble or drip is wrong to describe pouring lead from a ladle onto/into a sprue. I guess I meant the difference between a rowel and the Lyman is the possibility of mating the teet on the Lyman to the tapered sprue hole to create a seal. I don't see how that could happen with the rowel. I still don't see how you could avoid covering those cramer HP pins with lead if over-flowing a MP HP mold.

I have two rowels a #4 and a #5 for smelting, they're great ladles.

[btroj]

I use an MP 359640 HP mould with my Rowell ladle, no problems. I tilt it slightly so the pins are uphill so the lead flows off the other side. No problems at all. I have used an NOE RG mould with it too, same thing. No problems.

If you do get lead on those pins you can just pour more hot lead over it and it will all flow off.

[6bg6ga]

I also experimented with spru size and found the large spru was the better way to go.

[cbrick]

If you do get lead on the pins nothing more than a flick from a gloved thumb removes it, all of it IF your mold is at proper casting temp.

Modifying sprue plates isn't necessary IF the sprue plate is at proper casting temp. Most problems casters encounter with the plate is simply a plate that's not hot enough.

Rick

[Forgetful]

A little Bismuth goes a long way to combat shrinkage.

A large sprue is noted in most casting guides, including those found on here.

Zinc pouring has this problem in a major way. You need a propane torch to keep the sprue molten, to solve it.

I almost widened the sprue hole on one of my plates (very large boolit, ~1.5oz) because I couldn't get enough fillout. Turned up the temp, added tin, nothing worked. Thought about it. Then I switched from the bottom-pour pot to the lee ladle because the pot took 4 seconds to pour once (not fast enough)... Couldn't pour enough without needing refilling of the ladle. Tried an RCBS ladle, it holds enough and it's cast iron. Didn't need to nipple-pour, I just poured. Fill out not a problem. Turned down the temp, went back to original alloy, not a problem anymore.

[44man]

A propane torch on the bench is my friend. Cool plate or mold not hot enough, just play a flame around all. Don't hold in one place.

[Bullwolf]

A propane torch on the bench is my friend. Cool plate or mold not hot enough, just play a flame around all. Don't hold in one place.

I always have a propane torch on the bench as well. Sometimes it's even lit. :-o

A propane torch makes for a nice removable H.P. Pin warmer too. Saw a really nice picture of a pin holder, here on the forum.


- Bullwolf

[JonB_in_Glencoe]

A propane torch on the bench is my friend. Cool plate or mold not hot enough, just play a flame around all. Don't hold in one place.
Yep, a torch is very handy.
I use the HF butane torch. it's nice and small and with a touch of a button, I have a HOT flame.
http://www.harborfreight.com/http-www-harborfreight-com-micro-torch-42099-html.html

[JonB_in_Glencoe]

If you do get lead on the pins nothing more than a flick from a gloved thumb removes it, all of it IF your mold is at proper casting temp.

Modifying sprue plates isn't necessary IF the sprue plate is at proper casting temp. Most problems casters encounter with the plate is simply a plate that's not hot enough.

Rick
Rick,
thank you for all the comments you posted throughout this thread. I agree heartily with most of them, I have almost no experience with Ladles, so I can't concur with that, but I'll be on the lookout for a better one to try, I have the newer Lyman, it seems a bit small ?
Jon

[cbrick]

I guess I meant the difference between a rowel and the Lyman is the possibility of mating the teet on the Lyman to the tapered sprue hole to create a seal. I don't see how that could happen with the rowel. I still don't see how you could avoid covering those cramer HP pins with lead if over-flowing a MP HP mold. I have two rowels a #4 and a #5 for smelting, they're great ladles.

"Mating" or "pressure pouring" is not necessary. If that's what your doing and it works for you there's nothing wrong with it but it's not the only way and again, it's not necessary for quality bullets. I never pressure pour whether ladle casting or bottom pouring.

It doesn't matter if you get lead on the pins IF your mold is at proper casting temp, a flick of the thumb with a gloved hand knocks it right off the pins.

I have Rowell #1, #2 & #5. 5 for smelting, #1 for small bullets or single cavity molds & #2 for almost everything else.

Rick

[btroj]

The pins also run smoother if coated with a good lube, like Bullplate. The lead simply won't stick to that stuff. Hot mould, proper lube, no problems.

Jon, I got a #2 Rowell after much discussion with Rick. It holds well over a pound of lead when full and let's you pour lots of lead, and heat, into the mould. One ladle will fill any mould I own. the #2 is a snug fit in my RCBS pot but I wouldn't have anything smaller.

[JonB_in_Glencoe]

sometimes it's good to bring up an older thread about a common problem.