new caster learning

[scion19801]

So i think i have come up with a good culling process. Cast the rounds, using magnifier and good light - check for defects (flashing, wrinkles, anything that don't look perfect), then roll test (listen for perfect smoothness like rolling a marble or ball bearing. any clicking is a no go). Then weigh them to see where the batch dropped at.

Now for the issues:
1: seeing alot of wrinkles in the skirts. ( My guess is Mold is too cold?)
2: seeing an odd wrinkle pattern almost circular right at the ring (halfway) in the head, slightly behind it, and very repeatable in my last casting session.  (Not sure what this was about. Again possibly Lead to cold?)
3: Was seeing some that had very fine whiskers. (From what i've heard this should be the Ideal sport for things.)
4: My lead is freezing within 2 sec on the sprue. ( Again think my lead temp is too cold.)
5: After the casting session i checked the mold over and pulled it all apart to make sure things were ok. Did find a slight piece of lead that must have gotten done in one of the corners (maybe a 1/2 mm in diameter) that could have been causing some issues. Everything else looked good.
6: After getting a handful that passed the culling test. Some shoot properly, and still get some that want to spiral. My weigh out on the shortest pin gave me a .8 grain spread from 28.4 - 29.2 grains. This has been my largest spread yet in weight. But i was checking every 4 mold drops to make sure that the pins were set correctly to eliminate flashing on the skirts. I did toss my first 20 directly back to the pot after cast, knowing the mold needed to get a more consistent temp built in. then after seeing they were dropping ok, did my run.

My casting cadence is mold on its side. Pull up a the dipper touch the mold flip upwards to pressure pour. hold for a second or so, then quickly tip the dipper away. then repeat for the second cavity. set dipper back in the pot. wait a 4 count (sprue has already froze by this point) and toss the previous sprue back to the pot. tap the sprue open, tap the mold handles and drop the pellets on a towel. reach down and use the sprue (to keep the mold blocks parallel to each other) with a little wigle to close the mold. twist back upright, with the sprue coming closed and back over the pot to start the process again.

[Loren]

Now for the issues:
1: seeing alot of wrinkles in the skirts. ( My guess is Mold is too cold?) 
Yes, along with melt temp being low.  Get a thermometer...it will help a bunch with quality casting

2: seeing an odd wrinkle pattern almost circular right at the ring (halfway) in the head, slightly behind it, and very repeatable in my last casting session.  (Not sure what this was about. Again possibly Lead to cold?)
Again cold mold and melt.

3: Was seeing some that had very fine whiskers. (From what i've heard this should be the Ideal sport for things.)
I always see whiskers (not flash) as a sign that temps are good and I am getting good mold fill.  A little tumbling in a tub with the other pellets typically will break off the whiskers.
4: My lead is freezing within 2 sec on the sprue. ( Again think my lead temp is too cold.)
That is pretty quick. 


My casting cadence is mold on its side. Pull up a the dipper touch the mold flip upwards to pressure pour. hold for a second or so, then quickly tip the dipper away. then repeat for the second cavity. set dipper back in the pot. wait a 4 count (sprue has already froze by this point) and toss the previous sprue back to the pot. tap the sprue open, tap the mold handles and drop the pellets on a towel. reach down and use the sprue (to keep the mold blocks parallel to each other) with a little wigle to close the mold. twist back upright, with the sprue coming closed and back over the pot to start the process again.

I found that throwing sprues back in the pot really causes bad temperature fluctuations, driving your casting temps down.  I actually have furnaces.  One is a bottom pour and then just a plain furnace.  I throw sprues into the regular furnace and melt before being recharged into the bottom pour pot.  It helps my production by not having to wait for the main furnace to come back up to temp after recharging, and helps quality because I am able to keep a steady temp in the bottom pour furnace I am casting from.

Control your temps and that controls your casting.

[Chickenthief]

1, 2, 4 = lead + mould to cold
Lead +2-3% tin = in the 720+F range for optimum fill out.
If the total amount of pellets in the mould is under 200-250 grains then you pretty much need a hotplate to lay the mould on for several seconds during each casting cycle. Pour and then rest mould on hotplate until sprue has solidified. As you gain confidense and experience you will pick up casting speed and a hotplate will be void.

3 Finns equals to much puddle pressure, have never had problems with it unless i put the mould directly up to the spout while pouring. I have cast litterally tons of lead for black powder weapons (ie soft) over the past 35+ years.

OH and mould preheat!!!
Perfect bullets from gitgo is a result of proper mould preheat. No need to use good lead and time just to cast the mould up to temp. Hotplate ;-)

[triggertreat]

I don't know what casting pot you are using, or whether it is PID controlled or not.  If it is just being controlled by a mechanical rheostat, the temps are changing as the material quantity declines, not good.

I had this issue with my Lee Pro 4 20lb. pot.  I built a DIY PID controller for it and now my temps stay consistent regardless of material quantity.

Here is a link to my build along with the how-to videos to build it.  It's really easy to build:

PID controller build for your casting pot with instruction videos

One mistake I was making even with the PID controller in place was adding back in my sprue cuts right away during my cast.  Don't do that, wait until you are getting low and need to actually refill the lead supply.

[scion19801]

was able to get a pic of the cast circle defects at the ring of the head. Seem to be getting this alot. I know my temps were higher this time and i had alot of whiskers this pour and my spru puddles was taking about a four count to solidify. And it doesn't appear to be just one cavity or the other seems both do it, got way more bad than good.
Need to get a temp gauge and rule out lead temp. I have a 2 quart cast iron pot about half full and, and using an old propane stove top high BTU burner.

edit:
What is a safe temp range for the 2 cavity brass mold to not excced? Don't want it to/or overheat it.

[triggertreat]

was able to get a pic of the cast circle defects at the ring of the head. Seem to be getting this alot. I know my temps were higher this time and i had alot of whiskers this pour and my spru puddles was taking about a four count to solidify. And it doesn't appear to be just one cavity or the other seems both do it, got way more bad than good.
Need to get a temp gauge and rule out lead temp. I have a 2 quart cast iron pot about half full and, and using an old propane stove top high BTU burner.

edit:
What is a safe temp range for the 2 cavity brass mold to not exceed? Don't want it to/or overheat it.

Ok, I see.  I like my lead between 825° to 850°.  I get good fill out, and casts drop good out of the mould.  The mould needs to be hot.  I use a hot plate and mould thermometer to keep track of the mould temp on startup.  I run a little extra lead over the sprue plate to keep it hot while casting.  A damp rag can be nearby to cool the mould down some if frost starts occurring on the slugs.

[Mark Davis]

Those little spots are from lead splashing, sticking to the wall of the mold, and starting to harden before the cavity fills that full.

On large powder burner bullets, one solution is to pour on the edge of the sprue instead of straight down the hole.

For a pellet mold I would look at more heat in the lead, dipper, and mold, as a solution.

[scion19801]

Thanks guys. I ran things abit hotter last run, still seeing a few of the above pictured spots, not as many. I then started getting alot of flashing at the seems. Some i noticed only seemed to have it on one side of the pellet. It almost seem like the mold may have a burr and not closing down all the way. I was getting the whiskers as well. But they break away when you roll them, I found if i dont keep alot of lead in the hooded dipper. then the whiskers wouldn't be as bad.

[scion19801]

i think i just figured out my spiraling issue. there may be an issue with the mold. the pellets are out of round. i get full circle rifling engagement on the skirts, then on the heads only two spots are showing marks about 180 degress from each other on some. then on others it is 3 spots in a triangle so they would be 120 degree separation.
Basically they are not dropping perfectly round.

[Mark Davis]

If the pellets come out of the mold undersize and out of round, I'm pretty sure NOE want's to know about it.
And they will be very good about replacing the mold.

[scion19801]

Ok. So I tore the mold down again. Went over it and found a few burrs, some lead got behind the handle between the mold. Also found some nasty flashing burrs around the meplat area. Got it all worked and cleaned up.
NOE  Al  Swede called me and we talked. Told me to push the mold temp to 500 and try smoking the cavities lightly. He said my lead temp sounded good by seeing the same pic I posted here. Try again and see what I get.
So I made a double run. Made one run then put all my sprue cuts back in the most and took a 10 min break and started again. But I think that was what cause a lot of the same bubble circle to reappear agin. I had left my mold sitting over my melt to keep it warm and toasty, but it must have cooled down more than I thought. Got everything hot, had to make a few adjustments to the sprue plate as it wasn't cutting clean. Getting a lot of flash in the meplat area now. Al said it sounds like my tin content is on the high side. Got a ton of whiskers. But I found a hopefully ingenious way to deal with them. Managed to get 200 nice looking pellets tonight. Testing tomorrow to see what they.do.
So for those that cast and get/find whiskers. Grab a towel, put the pellets in the center. Fold towel over the pellets and grab the ends and roll/mix the pellets back and forth in the towel like they'd be in a tumbler. These came out so pretty and smooth. Man I hope these ones finally perform as they should.

[Wayne52]

The only time I got whiskers was when I used lead that wasn't pure, I don't have a temperature controlled pot and I think that if I had one I could have turned the temp down some and suspect that might have taken care of the problem.   Tin is really good to mix with the pure lead but that would be the only thing that I'd mix together.  I no longer use pellets that I've melted that were store bought because you never really know exactly what might be in them

[scion19801]

So. i'm still getting spiraling. got pics of what i found. getting a lot of flashing in the meplat area now. Also a close up of 3 of my meplats. was still getting a few of the circle defect, but got way more better ones this time.

[Mark Davis]

Flash on the meplat is a problem with your sprue plate, many casters run with the sprue plate loose enough to swing when you tip the mold.

I have been casting some every morning, they are getting better, but still not good enough to stash away for later.
The whiskers seem to be the problem.
 
Changes to my casting looking for good pellets;

Went to ladle pour, 35 years of bottom pour under my belt and filling those tiny cavities was just to exciting.
Being left handed, the ladles available way back when were all right handed so I got a new one.

I'm using a lee 4lb pot. Wayne's one temp pot works for him, so mine is set to max temp.

Bought an old clothes iron at the 2nd hand store, took the handle off and made a stand from MDF board, JB welded a block of 6061 aluminum to the face, Makes a good mold and ladle preheater, my casting space just did not have room for a hotplate. Works good.

Have spent some time several mornings adjusting the pin holders. They now do not leave flash on the bottom of the skirt, and the mold closes most of time. Started tapping the hinge pin after closing the mold, while holding the handles together. Brass mold would probably work better than my aluminum.

On Knife's advice quit using sawdust, and now use 20 muleteam and paraffin as flux. Lead is cleaner.

Wayne says pure lead= less whiskers, so all the lead I was working with got cast into cores for 300 grain jacketed swaged bullets. It was from lead flashing with the soldered seams cut out (20cents per lb from scrap yard). Broke out some plumber's pigs, axed them into pieces small enough to fit in the pot. Still have whiskers.

All the new movements in casting this way are clumsy to me, gotta get me some technique!

On the bright side, first groups were 6+" at 25 yards with a 75% reject rate.
Now getting 1 1/2" with reject rates 30-40%. 9 shot groups are usually 7 or so in 2 distinct groups and a couple flyers.

I need to have some kind of a divider on my bench to separate pellets from different cavities in groups, I suspect the worst whiskers are from cavities near the end of the mold, and the two group thing could be  pellets from different cavities.

JSB 25 grain pellets shoot 5/8-3/4" outside measurement.

[scion19801]

I'm currently setup casting the heavies. they weigh in about 28.8 grains. going to go try to get some pure lead at a scrap yard tomorrow. called them and they said they got about 500 lbs currently of pipe and pipe flanges. going for the pipe. $0.80 cents a pound. hard to beat that. Gonna try another run tonight adding in some more pure lead. I think my current batch is heavy on the tin.
To get rid of whiskers wrap them in a towel and twist the ends back and forth so the pellets tumble against each other. Worked really well to get rid of whiskers.
I have adjusted my sprue so that you have to bump it by hand to close it. it no longers falls open on its own. I also think it could be because I'm cutting my sprues to soon or not soon enough. Should i be tapping my way thru the sprue or all in one go?
I checked the best i could with calipers to measure the head bands at the widest point. Getting anywhere from .252-.2455. So i think my sprue cutting is messing with the heads. If i keep the roundness tolerance to .002-.003 i don't see very much spiraling. anything more and i reject cause they will definitely spiral.
did shoot a few groups. nothing to brag about. could get a nice cluster under 3/4" of three out 8. the rest are scattered around it. So things are getting better. Oh and i did manage to get a chipper at 29 yards. I think it was luck more than anything.

[Mark Davis]

Two scrap yards here to shop at, one wants a buck a pound, the other much more reasonable.

I want to open the sprue plate with hand pressure, If it has to be wacked, to open then the castings are rejects to me.

I have been experimenting with tumbling the pellets to remove whiskers too. First go was with 15 lb Thumbler's tumbler.
I just put the pellets in with no media and rolled them around. The went in nice, smooth, shiny.
Came out looking like the face of the moon, but not a whisker in sight!  Decided to test fire anyway, putting them in the mag of my Matador the were visibly small at the skirt. Amazingly, they were my best group at that point.
Made me think the whiskers are part of the problem.

Next experiment was small 1 lb capacity rock tumbler loaded with ground corn cob and turtle wax. Did not remove the whiskers. Did not shoot well either.

Then put pellets in a lyman turbo tumbler with dirty corn cob for an hour. The pellets came out dirty grey, but the imperfections were very visible. Sorted out the good ones. Blew the dust off, put about 70 of them in a sandwich bag with about 1/2 a drop of Mobile One synthetic motor oil. squished the bag around until the oil was distributed. These are the best shooters so far.

This evening, rubbed the edges of the mold face with a popsicle stick, just re smoothing burrs and suspicious of the spots right at the shoulder of the pin. Uncomfortable with the  sliver of light visible between the mold blocks.

Next experiment will be cast tomorrow. Then in the lyman turbo tumbler with new, crushed walnut media.


Your towel strategy sound good, I'm going to give it a try if... uhh...when the walnut media does not give sub MOA groups.

[scion19801]

Tonight's session is done. Tried a few things. Found that if I tip mold to dipper then rotate upright to pour then. Get dipper out quick but keep mold upright till sprue freezes the do the same with the next cavity. That seemed to cut down on bubble defect. Got 75 percent keepers almost a full tin in 3 hours. Sprue plate is tight to brass mold but still seem to get a lot of meplat flashing. Guess I'm gonna have to run it over sandpaper on top of glass to make sure it's flat. My furthest pin from handles seems to like to constantly hold on the pellet and require numerous taps to get it to pop. But when upright and open mold pins fall right out of place.
Still getting a lot of outta round meplats. Tried both gentle tape to cut the sprue and one quick fast cut. Same results. Hopefully once I switch to pure lead tomorrow things will clean up.

[Nvreloader]

Mark

I have been having good success cleaning up OEM CM HP pellets via tumbling,
I also use a Model "B" tumbler with 10#'s of SS pins, dump in 1000 pellets,
fill to within 1/2" of barrel lip of hot tap water, add a squirt of DAWN soap and run for 5 minutes, timed.

Dump the water and the pull the SS pins out with a magnet and collect the pellets,
I made a tube of a heavy weight towel, dump the pellets in, close the ends with my hands,
then tip each end up allowing the pellets to roll down to the ends of the tube for several trips,
then spread the pellets on a alum cookie sheet and set in the hot sun for 1 hr or until dry.

The amount of flashing I get is unreal per can, the tumbled pellets turn out very smooth and uniform,
no mold lines etc, I still need to roll test and weigh them and Wax them, before I shoot for groups,
as compared to other tins of pellets that are untouched etc.

I got 5000, all at the same time..................
these pellets seem to be very accurate out of 3 of my rifles, the Varmint, Gauntlet and the 79 QB,
haven't tried the Sentry yet, awaiting parts before tear down, slow leak.........

YMMV,
Don

[Mark Davis]

Don, I had discounted the thought of stainless steel pins. But with water they would not be so bad. My problem is that last vent line close to the edge of the skirt, If the flash would go away, hopefully accuracy will improve.
I have been talking whiskers, but the one vent closest to the edge of the skirt is more robust, perhaps flash is a better description.
Using an effective flash removal treatment, the hollow base pins can be adjusted just a bit looser, which will make the mold close better. I'm going to loosen all my pin holders and slip a shim under there, then tighten the screws.

Scion, with the sprue plate tight, adding heat can make the plate not want to sit flat against the blocks.

[scion19801]

i keep a close eye on the sprue plate, i can see daylight on one end that rotates when cold. we'll see what happens. I got 9 pound of pure lead and gonna add 44 grams of my previous batch, if i have fill out issues, to pick up a touch of tin. I ended up getting 63 pounds today for $54. got a lot of regular pipe lead. has 2 or 3 solder joints. and some lead pipe flashing about 4 or 5 of them.
Need to figure out an effective way to release the solder joints and keep them seperate from my pure lead as they should be tin joints. already smelted and cleaned up, and pucked about 6 of them weight about 4 lbs per puck. grabbed some paraffin way to use as flux.
cant wait to see how this batch goues tonight. I am determined to get this dialed in. LOL