Inconsistant Results In Two Bullet Mold

[Shooter30-06]

I have been casting for about a year and generally have had satisfactory results. I am using Lee two- bullet molds and dipping from a Lee furnace. I have noticed that I consistantly get a better bullet from the interior (closest to the handle) mold that the second/outside mold. This happens no matter which mold I fill first. I simply have more rounded edges and wrinkles from the outside mold. I have also attempted to cast at a higher temperature but have the same outcome. I would appreciate your thoughts on how to eliminate this problem since casting one at a time is pretty slow. I have to tell you I have gotten some really good information on this website. Thanks folks!

[AZ-Stew]

Try increasing the flow rate from your bottom pour. Doesn't take much. Sounds like it's not filling quickly enough.

Regards,

Stew

[JSnover]

try dipping the mold to help warm it. Does it happen all the way through the session or only in the beginning?

[theperfessor]

A-Z, he said he was dipping from a LEE pot. I missed that the first time I read it also.

- Check front cavity for proper ventilation. May need to break top edge of mold lightly with file for better venting of base.

- May need to enlarge pouring hole slightly and rechamfer sprue plate.

- Front cavity may not be as clean as rear cavity, it may still have a little oil or grease in it.

You don't tell us what weight/size bullets you're casting; this might help others help you more.

[JKH]

sounds like its not hot enough, there is more mass closer to the inner cavity which will keep the mold temp higher than the outer. Try getting a fresh ladle full for each cavity pour to keep temps up a bit more.

Also, it could be that the particular mold cavity that has issues may need further cleaning, how did you prep the mold when it was new? Aluminum is actually quite porous and will continue to ooze oil for some time if not prepped properly. Try scrubbing with Dawn dish detergent and an old toothbrush, then boil it with more dawn, then scrub and boil it again. It can be somewhat tedious but if you dont get all the oil out it will take a long time to do it via casting and frustrate you no end.

Jeff

[Shooter30-06]

To answer your questions, this has occurred in all three calibers I am casting which are 429, 358, and .458. I always get a fresh ladle for a pour into each cavity. I usually preheat the mold by setting it on top of the furnace during the initial meltdown and during any delays. I do not usually dip the mold into the lead whcih I intend to try. I am intrigued with Jeff's response since the last session was preceded some days before by a thorough cleaning with white gas. I left the mold outside to let the gas evaporate off but did not do any other cleaning. Maybe this residue was inhibiting the process but I continue to wonder why one mold cavity shows up as a problem more often than the other. I think the suggestion about enlarging the sprue plate sounds good also.

[mpmarty]

shooter3006 don't drill or dremel your mold until you have thoroughly cleaned it with brake cleaner and or boiling as earlier post suggests. After that if you still have a problem do a search here on leementing molds; finally if all else fails before picking up the dremel try smoking the mold cavities only with either a propane torch or an acetylene torch. Good luck and by the way, Welcome to the insanity.[smilie=6:

[lwknight]

I bet the last chamber that you usually fill is the 1 that gets more wrinkles.
If that is the case then its because you open the mold when the last cast cools. The last chamber does not give as much heat to the mold as the ones that sit there waiting for you to fill the last cavity. Molds will cool more on the ends than the middle.
Try casting the end cavities first then the iner last and see what happens.
Since you say that it happens in all 3 molds, it has to be your way of doing things like not casting fast enough to keep everything good and hot.

[AZ-Stew]

Sorry, I DID miss the part about dipping. In the Navy, we said RTFQ (Read The Cotton-pickin' Question). I didn't. The solution is the same, though. Get more heat into the mould by increasting casting speed.

Sounds like you need a bigger dipper. As lwknight says, one hole in the mould is cooling before you get a chance to fill it. So either you need to fill the second cavity more quickly, or you need to get more heat in the system by increasing pot temp or casting faster (Cast, cut sprue, dump. Cast, cut sprue, dump. Cast, cut sprue dump. Save the sorting for later.)

Regards,

Stew

[Leftoverdj]

You can't clean a mould with a contaminant.

We get this non stop and it never ceases to amaze me.

[MT Gianni]

I would try loosening the sprue plate screw. It amazing how a little looseness there improves venting. This is paticularly true if the base is where your wrinkles are and incomplete fill. If it is in the nose try filling the outside cavity first. That will keep heat in that cavity longer and reduce temperature related wrinkling.

[chris in va]

FWIW, I'm brand-spanking new at this but discovered something with my 9mm Lee double mold today.

I was also getting the partial fill problem with the outer hole. No amount of smoking, lubing, or cleaning would fix it. Most of the boolits had a rounded base. Turns out my lead was too hot! Once I turned down the heat a bit, the alloy would pour nicely into the sprue holes and pillow up instead of run off the mold. Every boolit cast after that was absolutely perfect.

[765x53]

One cavity = one ladle full, second cavity = second ladle full, etc., etc.

[JKH]

I am in the not enough heat camp, dipper pouring is slow and tedious no matter how practiced you are (I am sure there old laddle dippers that will counter that point, however I let it stand).

What type of ladle do you use? an open top is slower and will allow the melt to cool considerably, if you have to ladle cast I would highly suggest a Rowl bottom pour type of lade which has a lot of mass to it to keep alloy temp higer and less surface area of the melt is exposed to the air which also slows cooling.

As stated by another member, it has to be technique, not the mold as you are having consistent results with multiple molds, cause and effect.

Keep plugging, you'll get it :^ )

Jeff

[mooman76]

If increasing the heat doesn't help I'd go for the venting problem especially since you say on cavity fills good and theother doesn't. Loosen the sprue plate a little. You will know immedetely if it works.

[runfiverun]

venting is my pick too the perfessor and others had good suggestions.
tightening and loosening the sprue plate can fix issues on bases with all types and sizes of molds.
the angling on the inside of the mold blocks can help too but takes a light hand.

[montana_charlie]

I don't have any multi-cavity moulds, so I have refrained from saying anything. But, I just read the whole thread to see where the discussion has gone. It looks like every aspect of troubleshooting the problem has been mentioned, but apparently no solution has been found.

So...trying to think outside the box...

That front cavity seems to be the troublemaker. It is also closest to the sprue plate pivot.
That means it is more likely to get contaminated by any lubricant used on that pivot.
This could result in a 'dirty cavity', no matter how spiffy it was when you reassembled the mould after cleaning.

What kind of lubricant are you using...and how much?

CM

[stephen perry]

If you are not doing this check temp in pot before starting. I would suggest 700 deg if WW. On my LEE 10 pot that is a setting of 8.25.

Also pick up the tempo. Instead of 200 bullets per hour go for 300-400 per hour. If I feel good I like to do 800 bullets per hour with a single lots more with a 2 ,4, or 6. Cast the forward bullet first and see if that makes a difference. Flux every half hour and stir top to bottom. You should do better.

Stephen Perry
Angeles BR :brokenima

[Shooter30-06]

Just to briefly update - I took the advice of Chris in Va. and decreased my temperature on the furnace and had much better results. I had nearly as many usable bullets coming from the front mold as the back one. I have to say this was counter to my expectations since I agreed with the posts that a wrinkled and rounded result usually means inadequate temperature. However, during the prior casting session I had increased temperature and saw worse results. Thus, Chris"s suggestion seemed worth trying and worked. Thanks to everyone who commented or made suggestions.