Bullet base mold fillout???

[seagiant]

Hi,
I have an RCBS 38-150 (KeithStyle?) SWC mold that I'm having a little trouble getting the base of the bullet sharp! This is a great mold and the bullets are VERY accurate even with the ones that the base is a little rounded. I use this bullet in .38spl and .357 mag. with excellent results but this bullet coming out with a soft base every now and then bugs me!

I've tried putting the heat up or down.Poring the mold close to the nozzle or farther away(I use a bottom pour pot) using mold release not using mold release,ect,ect. I'm sort of out of ideas,also the bullet is sharp on driving bands and nose,only soft on base??? Hopefully some of you might have some ideas on this. Thanks!

[buck1]

When you fill your mold, let the lead overflow for a second or two after its full. and also check your vent lines for lead, and I have had luck with a slower fill of the cavs at times. If all else failes add a little tin or EVER SO SLIGHTLY open some vent lines a itty bitty bit. ...buck

[seagiant]

Hi Buck,
That's a good idea I remember now that you mention it about taking a hobby razor knife and just running it in the vent lines to clear any burrs in the mold. I'll try a good cleaning and do the vent lines and see what it does. Thanks!

[fourarmed]

One thing I have found to fill out those really stubborn molds is to make the bottom-pour pot work like a dipper: press the mold tightly against the spout and open the pour lever for two or three seconds. Then drop the mold down a quarter to a half inch (a stop helps) and let the alloy continue to run for just a fraction of a second. (If you don't do that last step, you get tiny little sprues that tend to stick to the sprue plate.) I'll bet that gives you fewer rounded bases.

[44man]

I've been casting since the 50's and have tried a gazillion times to make boolits from a bottom pour furnace. I can cast 1000 straight boolits with a ladle and get only four or five rejects. With the bottom pour I pull my hair out so I just quit trying. A tiny piece of slag in the spout will end all hope of getting a good boolit. The ladle can be cleaned.
The top inner edge of the mold blocks should be broken with a fine file to help vent the base. Just a deburring is all you want.
Any of you fellas getting all perfect boolits from the bottom pour rank right up there with Einstein. Just not worth the trouble. Yeah, I will hear all kinds of comments but none of my friends can do it either, and that takes in about 500 years of casting experience. We ALL own ladles now!

[Bass Ackward]

Hi,
I have an RCBS 38-150 (KeithStyle?) SWC mold that I'm having a little trouble getting the base of the bullet sharp! This is a great mold and the bullets are VERY accurate even with the ones that the base is a little rounded. I use this bullet in .38spl and .357 mag. with excellent results but this bullet coming out with a soft base every now and then bugs me!

I've tried putting the heat up or down.Poring the mold close to the nozzle or farther away(I use a bottom pour pot) using mold release not using mold release,ect,ect. I'm sort of out of ideas,also the bullet is sharp on driving bands and nose,only soft on base??? Hopefully some of you might have some ideas on this. Thanks!

Sea,

Your mold is not venting at the top before the mix solidifies. Since you can't heat your way out of this problem, you need to take a stone, or a file if you can be gentle, and put a slight taper on the top of your blocks so it can breathe. Then you can turn the heat back down.

I cast bottom pour and have no molds that don't throw 100% yield after they warm up.

[Maven]

Seagiant, After you do what Bass says, also try loosening the srue plate so that it almost swings of its own weight. That sometimes helps improve venting as well.

[StarMetal]

I'd quit shooting cast if I had to use a pot and a ladle. I use to do that and to me it's god awful slow and tiring. I'll take my RCBS furnace any day of the week. The only rejects I get are the ones till my mould is up to operating temperature, that is if I didn't preheat them.

Joe

[seagiant]

Hi Fellas,
Well I'll tell you something I'm getting my notebook and writing all this info down so I don't lose it or more important don't forget it!!! Being gone from home for months at a time you seem to go through endless learning curves on these things and I think this will help. Thanks again!


U.S. Merchant Marines!
We carry the Fight!

[David R]

Umm bottom pour for me! Ladel is a pain in the butt. All my boolits come out except till the mold is warm and most of them do too. I just expect to throw the first dozen or so back.

Think of it, 6 cavities 45 cal, just fill em up with an endless supply of nice hot molten lead. No stinkin ladel needed. I use Lyman, RCBS and Lee molds.

Back on subject. Throw in a little tin from where ever you can find it, if you HAVE to, buy a pound of 95/5 from homo depo and use 1/2 the roll. See what it is like to have em come out perfect.

Let us know how it works out.

[seagiant]

Hi Gentlemen,
Well with so many people here trying to help me out I figured I better go work on the Mold and see what I could come up with. I took it all apart cleaned it with degreaser and ran a knife tip over the vent lines and then put a very slight bevel on the upper blocks where they meet with my trigger stone and tensioned the sprue plate correctly and the mold started throwing perfect bullits almost from the git go! The other thing I noticed is that the bottoms of the bullit is a lot smoother than it was and better looking now? I want to thank everyone for the suggestions and help!!!

[floodgate]

44 Man:

"I've been casting since the 50's and have tried a gazillion times to make boolits from a bottom pour furnace. I can cast 1000 straight boolits with a ladle and get only four or five rejects. With the bottom pour I pull my hair out so I just quit trying."

You have to remember, bottom pour only works on even-numbered days of the month, ladle on odd-numbered; EXCEPT on Leap Day (Feb. 29), when neither works.

floodgate

[beagle]

Aw now, floodgate, you know that's true only in CA.

I can cast with either but prefer the bottom pour as it's less tiring over a long run.

Bass is right on the venting. Bevel the top edges where the mould blocks split the cavities with a fine stone. Just enough so that you can see a little "shine" along each edge of the block when held up to the light. This should cure base fill out.

Then vary the distance that the lead drops from the spout on the bottom pour. Some moulds like it hot with the mould right against the spout and some like different distances. You can vary the temp but I set mine by thermometer and leave it alone and vary the drop distance. Some moulds like to be canted left or right a bit before you can get good bullets. You'll jet have to find the sweet spot. But above all, bevel the block edges. First thing I do when I get a new mould./beagle

[44man]

Floodgate, I love your answer!
I admit to getting some good boolits from the bottom but I think it really depends on the furnace being used. I have never tried bottom pouring with my new Lee pot. My Lyman was made in 1961. My friend has three new Lyman pots and they don't get hot enough even for a ladle. One had the thermostat removed and runs wide open and boolits are still wrinkled. (I can't even get them to work.)
Maybe a quality furnace works but being retired on a fixed income, I can't buy more then a Lee. I even had to resort to making my own molds to save money.
I know bottom pour works because all the commercial boolit makers use them. My stuff just doesn't.
I just cast a 20# pot empty running 2 molds (with a ladle) and did not get one single reject. I pre-heat my molds with a little mold furnace I made and the first boolit from each mold was perfect. I kept waiting for that bad one to appear but none did. 20# of lead with zero rejects makes me happy.
I can understand that a six cavity mold would be a pain with a ladle, however I don't have one. I have a lot of Lee 2 cavity ones and even running two molds, one my home made and one a Lee, the Lee gets hot enough to frost boolits but mine doesn't. If I used just Lee molds, I could run three at a time.
I guess what I am saying is that if you have a quality furnace it works but if you have cheaper stuff like me, the ladle is best. Besides, I am so good with it, I won't change (being a hard headed old fart!)

[fourarmed]

The molds that have caused me the most trouble are: molds for BIG boolits, big molds for little boolits, and hollowpoint molds. The extra pressure you get from a dipper or from pressing the sprue plate against the spout of the BPF often makes all the difference needed.

[buck1]

I get a better ratio of keepers with the ladle, but even with the throw backs the bottom pour gives more good bullets in the same amount of time . Just my .02 ......buck

[44man]

I will never forget when one friend brought several furnaces to work and set them up on benches in the tool room. He had a pile of molds and went to work. He was a lead so just put his guys to work and spent the day casting boolits and round balls for himself and some of the other guys. I stopped in once in a while and was amazed at the piles of balls and boolits. Eight hours of casting can make a lot. BUT, I never seen one good one in the bunch. I hurt his feelings when I said to throw them all back in the pot! He was using the bottom pour on one pot and a ladle in the other. The problem was that neither pot was getting hot enough with the knob all the way up.
I was having a problem with my old Lyman and called them for a new thermostat. The woman laughed when I gave her the model no. She could not believe it was still working. No parts though! I took out the thermostat and cleaned the points, then adjusted it. It still works but not good enough for the bottom pour so I plugged the hole.
I would cast a bunch, then the sprue would freeze before removing the ladle. Darn thing was going cold before turning back on. Even the lead in the pot was solidifying. It works pretty good after I fixed it.
Maybe the Lee would work because it gets a lot hotter and holds temperature good but I am fixated on the ladle. Kind of like the only sex available for an old codger!

[JohnH]

Way back when I was young and just four days older than dirt, I had a couple Lyman molds that gave me fits with exactly the problem you describe. I solved it by making sprue plates from 1/4" 6061 aluminum. 'Course as has been mentioned, they swung freely but not loosely, and probably vented better than did the factory steel plate. The thing about that is that even swinging freely, the steel plate would reject bullets. I never had that trouble with a mold up to temp with the aluminum plate.