ROUNDBALL CAVITIES

[Tinhorn]

MY roundballs are LOUSY! Cavities, wrinkles, stuck in mold, the list goes on. I need Help!
My gear- NEW Lee .490RB mold, Lee leadpot set at #5 heat, Lyman lead dipper that fits sprue plate, pure lead from Midway, paraffin for cleaning dross.
What am I missing, talent? steady hand? I don't get it, these should be good bullets. The lead LOOKS nice and clean.... Help me out, somebody! Tinhorn

 

[Grenadier1758]

The wrinkles and cavities are a sure sign that the lead is too cold. Turn the heat up. I have my Lee Lead Pot set at 8.

 

[bang]

Soot the mold with candle.
Heat the mold. I put mine on top of pot while lead is melting.
Pour till the puddle on sprew stays liquid a couple of seconds recycleing the lead and when you cut it it seems soft. This is when you know the mold is hot enough.
I find the lead pours best at close to 800^.
I use 1600^ aluminum antieize on the cutter, hinge and alignment pins. Resoot the mold occasionally.
Add small chunk of wax to molten lead to clean. It may flame but don't panic. Let it burn out. A good time to put mold on top to get some soot. IMO if it doesn't flame it's not hot enough. Once out stir and spoon out debrie. Reapply wax occasionally. Not technically needed but won't hurt and an opportunity to soot.
I pour till the puddle stays liquid about 5 seconds then let mold cool no more than one minute. Usually that's at the point I need to add lead to the pot. I just lay the mold on the top so it cools a bit but stays hot enough to pour good.
If I'm pouring in cold weather I keep a propane torch handy to keep the mold hot.

 

[sussexmuzllodr]

Slightly hold the mold at an angle as you pour. I will ensure a complete fill.

SM

 

[Tinhorn]

MORE FROM TINHORN- So my frustration boiled over, I snatched up my .562RB mold for my Leman barrel, dead cold, off the bench, as cast 2 very acceptable bullets, no soot, no preheat, no nothing. 1 and done.
And the Difference Is: that 10yr old .562RB mold has lots of straight gas vents, and the new mold has about 4 for the whole mold, both block faces combined. I Emailed Lee Precision, and told them to slow down their Surfacing Flycutter to 1/3 speed to make more vents. I breathlessly await their response...…...Tinhorn

 

[sussexmuzllodr]

MORE FROM TINHORN- So my frustration boiled over, I snatched up my .562RB mold for my Leman barrel, dead cold, off the bench, as cast 2 very acceptable bullets, no soot, no preheat, no nothing. 1 and done.
And the Difference Is: that 10yr old .562RB mold has lots of straight gas vents, and the new mold has about 4 for the whole mold, both block faces combined. I Emailed Lee Precision, and told them to slow down their Surfacing Flycutter to 1/3 speed to make more vents. I breathlessly await their response...…...Tinhorn

I noticed on a new lee mould my Nephew had in fact does have a new kind of surface finish on it .
SM

 

[Bledfor Days]

I'm guessing the gas vents are the little lines on the face of the mold. Here's a pic of a
New Lee mold
TC from the 80s
Lyman from 80s

 

[mooman76]

Add a tiny bit of tin to your melt. It won't change the hardness of the lead but helps the lead flow better for fill out. Like someone else said turn up the heat. Every mould does different like guns all have their own personality. Also did you preheat the mould?

 

[Tinhorn]

Thanks for the help, Bang and Grenadier! I went out to the shop and cut 4 lines of gas vents into the blocks with a Jewelers Saw, cleaned up with a mill file, and within 4 pours, Good Bullets...… Lead pot at #8 heat, hold dipper into sprue plate 5 seconds, good roundball. I have another mold coming from Midway in .495" for my rifle (.490" for Belt Pistol) and I will for sure cut the gas vents in it before I use it. I wonder what Lee Precision will have to say about my Flycutter suggestion? Tinhorn

 

[Tinhorn]

Bledfor Days- You're right on the money, the gas vents on the new molds plug with lead immediately in the pour. and no more gas gets out. All your other molds vent all the way to the top of the pour. Big difference......Tinhorn

 

[SDSmlf]

I have a couple of Lee molds with the ‘newer’ style venting and have no issues. Work just like the ‘older’ style. Probably have a dozen Lee molds for muzzleloaders.

 

[Bledfor Days]

I'm also setting the volume knob to 8.

 

[EC121]

I have used Lee molds for years. Poured good balls and never worried about the vents. However, I smoked the mold and used a thermometer to set the temp. Usually about 775deg. or so. It will vary with the pot level. When the temp goes up I add more lead. Near 8 on the knob scale.

 

[Jay Templin]

Gotta hold yer mouth right, and squint just so.

 

[Eterry]

Some molds drop easier than others. I use a small nylon hammer to strike the hinge, some molds barely need a hit, some do. I think RB molds let the bullet fall easiest. I smoke my molds before first using, then they seem to get better with age. Another thing I've noticed on Lee molds is being sure they blocks align properly. An older mold can be bad about this. I have a couple I have to check the underside to assure alignment is on. You shouldn't be getting lead in your vents...maybe you need a tighter hold on your handles. 90% of my molds are Lee.
keep your lead and mold hot, I mold two different bullets at a time so the sprue can cool down while i pour a second one. Try it.

 

[Tinhorn]

I'm OK for now, and I noticed that the flycutter made a lot more vents in your RB mold than mine had. I am sticking with the jeweler saw process for now. Does Lyman still make RB molds? I had their very intricate 500g Minie mold for a Navy Arms rifle, maybe 50 years ago, prior to shooting patched ball rifles only. It was steel, and very well made. As I recall, I bought the handles separately from the mold blocks, and they got hot while casting. Tinhorn

 

[mooman76]

Yes Lyman does still make RB moulds and RCBS also. I crank my lead pot up all the way and as I cast I gradually turn the pot down as the mould heats up.

 

[VADSLRAM]

I always get the first 4 or 5 casts all wrinkled. I just chuck them back in the pot and keep pouring. Once the mold get hot they cast just fine. a cold mold will "grab the lead and make it look wrinkled.
I have found that casting with the lead too hot you get more shrinkage, sometimes so much that I get a dimple at the sprue location. So I mold at just past the melting point. They solidify quicker that way too and I can darn near go production line speed. It does make the first couple mis cast but It works out in the long run.

 

[Scoper05]

The lead is to cool and the mold itself is too cool. And like mentioned hit it with a lighter or a candle and get some black stuff on the inside of your mold.

 

[Tinhorn]

OK, got the answer from Andy at Lee Precision- He says increase the lead-pot temp to the max to burn out oil in the mold, and impurities in the lead to get good fill-out and prevent gas bubbles. I told him about sawing more gas vents in the mold block, but he didn't address that. So that is the Official Word from Lee Precision on wrinkled, pitted roundball from their mold. Andy says frosted appearance is OK. Tinhorn