Darn bullets are coming out waaaay to big

[Ohio Rusty]

8 pounds of WW lead, fluxed with sawdust. 2 ounces of tin solder added to that 8 pounds as my casting alloy. Using a .429-240-2R 6 cavity Lee mould. All bullets are coming out .438 to .451 !! Using a Lee bottom pour at about 550 to maybe 600 degrees according to the dial. Sent the mould back to Lee with bullet samples of oversized boolits. I can't even get them thru the sizer. They sent the mould back saying all cavities mic'd .429 and the mould drops a .430 to .431 boolit. They also said that my boolits weren't filled out all the way (which should make them smaller) and they also said maybe I have zinc in my lead. (No zinc !! and even if it did have any zinc, the boolits would come out smaller).
So the next thing is this coming weekend to remelt all the boolits I made and cast a dozen or so boolits in each cavity one cavity at a time. Then measure all the boolits that come from each cavity to see what the measurements are of each cavity. I have NEVER had this issue of oversized boolits. This is my first 6 cavity mould and maybe the last. I have always had excellent results with single and double cavity Lee moulds. I'm definitely not a newbie to pouring lead and this one perplexes me ....

I used this same alloy and cast boolits in a Lyman 429244 mould and the boolits dropped from that mould at .431-.432.

Ohio Rusty ><>

[Jim]

Rusty, your measurements have a pretty wide range. Is there any chance the blocks are not closing properly? I've had that problem with a coupla' Lee molds and have to check 'em every time I close 'em to make sure the blocks are shut tight.

I dunno, bud, that's just the first thing that comes to mind.

[Springfield]

Make sure you aren't holding onto the sprue cutter handle, it will hold the mould open. With those kind of specs you would have to have some substantial finning.

[prs]

Agree with Springfield. Make sure your mould faces are clean and not dinged, then keep your hands totally clear of the sprue handle until you are ready to slice. I tend to keep a very modest handshake pressure on the main handles until the initial freeze of all the sprue strip, then rest it 4 or 5 seconds before slicing with almost no effort. I cast right at the edge of light frost and with a large capacity 6 cavity mould like that, I tend to be close to 700F alloy temp.

prs

[DLCTEX]

+1 on sprue handle being the problem. Also you must have been casting wit a cold mould to not have gross finning if the mould was open that much. I preheat my moulds on a hotplate and get keeper boolits from the start and no danger of breaking the sprue handle due to cold sprues.

[John Boy]

My 2 cents ... hold the mold handles and move them up and down. If the handles wiggle - tighten the bolt.
If the handle bolt is loose, the mold halves will not be closing perfectly in line to each other. Also make sure the pins are lubed. I use paraffin because it does not leave a residue ... Good Luck

[montana_charlie]

They also said that my boolits weren't filled out all the way (which should make them smaller)
... ??? ...
Seriously?

[Ohio Rusty]

Last Sunday I decided to clean the mould outside and take a closer look. I cleaned the inside of all cavities with a carbon-tet based cleaner, then was using carb cleaner on the insides of the cavities when I noticed something obvious and odd. I could only see it in the sunlight. It appeared there was a hairline burr or lip sticking out around the cavities. I could see the sun reflecting off the lip. I immediately surmised that a full length milling burr or lip was sticking out from around all the cavities. That must be holding the mould halves apart to give me the oversize boolits !!.

So I took a fine honing stone and stoned all the edges of all the cavities back toward the inside of the cavities to remove that burr line. Any burr sticking out would now be either honed off or pushed toward the inside of the cavity where it wouldn't be cause a problem. I then re-melted the same oversize alloy boolits and repoured them into the cavities. I made 8 to 10 of each cavity, one cavity at a time. After the boolits cooled, I mic'd them and they all turned out .430 to .433 depending on the cavity. That burr line must have been the issue. Now the mould is usable and I won't strip out the screws and tear the sizer off the reloading bench again trying to get oversized boolits thru the sizer. All of these sized very nicely without too much resistance. This Lee mould needed some 'fluff-n-buff' like my Keltec .380 to get it working properly.
Ohio Rusty ><>

[williamwaco]

Make sure you aren't holding onto the sprue cutter handle, it will hold the mould open. With those kind of specs you would have to have some substantial finning.

10 to one: This is your problem.

See this article:


http://reloadingtips.com/pages/missing_tumble_lube_grooves.htm



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