Good vs Bad Sprue Shooting Test: Lee Mold

[Dean2]

Rifleman

I am not trying to sound like an elitist or snob but I have almost always found the "Budget" route to be a far inferior choice. It can be made to do the job but the smoothness, proficiency and accuracy is usually not anywhere close to the quality alternative. I have gotten to the point that I will save a little longer to buy the well made version rather than put up with the aggravations of a cheaper copy. I find the cost difference is usually only 10-20% and to me that is well worth it for the better model. The re-sale on the top of the line gear is a whole bunch better too.

The better molds hold the heat better, cast far fewer rejects and properly cared for are impossible to wear out. In addition to the pleasure I get from using the better gear and teaching others how to use it, I would also far rather leave an inheritance of quality gear that will last a few more lifetimes and the older I get them more I think about that.

 

[necchi]

I find the cost difference is usually only 10-20%

In this case the Lee vrs Lyman mold cost is over 350%,, we're talking the difference between $20-25 to $70-80.
That's a significant difference.
The OP has many Lyman molds,, he's just having trouble with this one Lee that he's trying.

There are nuance differences in the method used to cast when changing from Steel to Aluminum alloy molds.
I think in this case the issue is the actual pour,, there's a small tipping movement made with the wrist during the pour, starting with the mold at an angle then leveling as the pour finishes the cavity, allowing molten lead to "swirl" when filling. The new double molds are a PITA, and I've found over pouring the final at the sprue helps,, the super hot 1000° melt temp isn't helping,, it's over kill.
Many of us have and still use Lee molds with great success, don't get me wrong I have several Lyman also,, but there is a different learning curve with the Lees. If Spike Buck stays at it he'll figure it out.

The biggest lesson in this thread is bad cast ball don't shoot as well as good cast ball.

 

[mooman76]

Another thing I don't think mentioned is make sure you leave a good size sprue puddle. As the lead cools and shrinks it can leave voids especially when it doesn't have the lead puddle to contract with.

 

[AZbpBurner]

Great minds think alike - I think it's the clear desert air! See the end of my 2nd point in my comments above.

Casting voids happen easiest with those using the bottom pour lead pots when you fit the pour spigot into the recessed sprue plate hole. No puddle allows the metal to contract & instead of filling with lead, they form air voids.

 

[mooman76]

I guess I missed that point but it was worth mentioning again. For awhile (many years ago)I was trying to get the sprue puddle down smaller thinking it would be better in the long run. Worked fine on the steel moulds that stay hotter but when I used my Lee moulds, I started having more rejects.

 

[Spikebuck]

For awhile (many years ago)I was trying to get the sprue puddle down smaller thinking it would be better in the long run. Worked fine on the steel moulds that stay hotter but when I used my Lee moulds, I started having more rejects.

I noticed this myself. On my Lyman molds, I have, over time, cut way down on the "puddle" size with very little excess. Being my first experience with a Lee mold, I followed my Lyman experience and after getting past the "bridging" issue I started with the same "small" excess and it was a disaster. I increased the size and could see it "settling" into the mold.

I didn't see that Lyman offered a .575 mold...only .570, but maybe I missed it. And then there's RCBS molds, but all I see on their website is .4xx sized molds.

I'm sure I'll get past the learning curve. I want to thank everyone for their inputs. Next batch I'll cut back the lead temp to what I normally do with my Lymans, but let the mold heat up better (though I thought I was doing that to begin with). Since this is a two-cavity mold, I'm going to enlarge the pour hole on one of the cavities to see if that helps. Then I'll let it sit a few seconds longer before whacking the sprue cutter.

 

[James Morris]

I've started tumbling my round ball in my homemade tumbler mounted in my lathe. Tumbling a couple of hundred for 45 minutes makes the sprue simply disappear and I no longer bother looking for them when loading and still winning events with them.

 

[Kansas Jake]

I have an old rock tumbler that I haven't used for years. I may have to put it back to use and start tumbling my home cast RBs.

Do you add any oil or stuff to keep the balls from oxidizing?

 

[Rifleman1776]

Do you add any oil or stuff to keep the balls from oxidizing?

Yes. One tiny squirt of WD-40 will do the job. Not real important but yer balls will still be purty after a few months or years.

 

[M. De Land]

Couple of tricks I picked up using my Lee molds for round ball casting are:
1. Take the sprue plate off and sharpen the bottom of the pore hole by working it flat across a diamond lap or stone. This cuts the sprue more efficiently and opens the hole a bit leaving the edge sharp.
2. With a carpenters pencil add a layer of graphite to the bottom of the sprue plate and the top of the mold block. This keeps the lead from adhering to both helping immensely in making a cleaner sprue cut.
Let the lead pot heat up enough to leave just a hint of frost on the balls for the most complete fill out.
Heat the mold up by dipping the corner of it in the pot for the first casts then work out a cadence to keep that hint of frost going on each ball. This is a very good temperature check for both mold and pot melt.

 

[hawkeye2]

"Take the sprue plate off and sharpen the bottom of the pore hole by working it flat across a diamond lap or stone. This cuts the sprue more efficiently and opens the hole a bit leaving the edge sharp."

That is a trick I learned many years ago and is very important with Lee molds. I have no problems with Lee molds but I have found the sprue plate to be distorted, possibly by the process used to cut the hole, and the first one I tried galled the top of the blocks right away. Stoning the bottom side makes a better fit on the blocks, eliminates the wear and cuts the sprue better. Also, if you have problems filling the mold fast enough don't be afraid to take a countersink to open the hole (stone after). Replacement plates are cheap and Lee's customer service is great. It's not a bad idea to keep an extra plate and some small parts on hand anyway.

 

[Kansas Jake]

Thanks. I'll try that.

 

[longcruise]

Something I've never done to any of my many Lee molds but am going to try it next casting session. :hatsoff:

 

[Spikebuck]

MD, thanks for the excellent tips.

Per the instructions that came with the mold, they warn about galling between the sprue plate and mold and recommend some beeswax or high-heat lube, which I used. Do you find that with your procedure this becomes unnecessary then and the graphite is enough?

 

[Billnpatti]

1/2 inch hole in the sprue plate ?????? Surely that is a misprint. Did you mean that you used a 1/2 inch bit to enlarge the hole? How big was the actual hole in the sprue plate when you finished enlarging it?

 

[M. De Land]

The main thing to prevent mold gaul is to get the bottom of the sprue hole ground flat so all burrs are removed.
The pencil graphite works as both a sprue lube and keeps lead from sticking to the bottom of the sprue plate and top of the mold.
This works with any mold iron, bronze or aluminum.
Another thing I learned to do on gauled molds is to remove the pin and sprue plate then turn the mold upside down on top of a piece of sand paper over a sheet of glass to remove any gaul scratches in the mold top.
This enlarges the hole slightly but cleans up the mold top very well.
The pin is pulled by putting copper jaw liners in a bench vice and pulling the mold away from the pin after a slight twisting motion.

 

[Sun City]

I bought a PRB mould from Lee about two weeks back and I've been casting bullets of all kinds since 1948 and I've never before seen a mould this poor delivered new...as for having an obvious flaw/flaws! The entry holes in the top of the mould block are oval/elongated and not concentric! There's no way in hades :cursing: this mould can deliver accurate projectiles! When I contacted Lee one of their 'talking heads' advised me that this was normal! I couldn't resist telling that guy that his comment was pure BS!!

Untitled by Rick Mulhern, on Flickr

 

[mooman76]

But the RBs do shoot accurate. Others moulds like RCBS and Lyman have a sprue and they shoot accurate too and they have more weight displacement than the Lee does to throw it off. Proof is in the shooting.

 

[smoothshooter]

Putting in just a tiny pinch, literally, of powdered graphite in the container you tumble them in works wonders. The balls come out almost black and somewhat shiny.
Have never had any of them corrode even after being stored for several years.

 

[pwbsmokey]

Years ago I had a T/C .490 aluminum mold, and I was having fits trying to cast with it. Probably 75% had to go back in the pot. Then I got a Lyman mold and had no problems. My melting pot is a Lyman Mini-Mag, and there is no temperature control. I would get wrinkled balls as the mold heated up, then a few good ones, then frosted ones when the mold got too hot. I could never get the right cadence to stay in the sweet spot of the mold temp. I sold the rifle and molds and now have a 54 cal. GPR and a Lyman .530 mold. I cast about 6 balls that are wrinkled, then I'm good to go. By the way, I bought all 3 molds on ebay, and they were priced between $20 and $40, so at least for me, steel molds are the way to go.