Out-Of-Round Question

[BenW]

Hey all, first post here. I've recently started casting, and my first batch boolits are severely out of round. I'm using a Lee 401-175 TC mold. I can see and feel the part line. Measuring across the part, I get ~0.398", along I get 0.405". I have cleaned the mold, and the problems have only gotten worse. I can close the mold completely, then shift the mold halves past each other to get the cavities to meet better, which suggests to me that the pins are loose or something like that. I'm thinking of getting a new mold, but in the meantime I have a question:

Can I size these boolits to get them more in round or is it too oblong?

Thanks for your help!

-Ben

[uscra112]

Welcome to the wide, wide world of Lee.

If I had to use those boolits, and I had a lathe, I'd make a swage tool to "bump" them round. Sizing will not make that .398 dimension any bigger.

(Full disclosure - I do have a lathe, and I did have to do this for some boolits from a Lee mould recently.)

[Lance Boyle]

I'd adjust the pins like you mention. Looking at the mold from the sprue plate side is the cavity visibly out of round? If so not much is going to fix that up front.

You may also trying a cooler alloy and a hotter mold and see if that helps.

[Pb2au]

Get a hold of Lee. It sounds like something is suspect in the mold itself. The pins are most likely the culprit. Lee won't know there is an issue unless we tell them. I just had a sprue cutter lever break on one of their 6 cavity molds. 6 days later, new lever.

[243winxb]

.006" is too oblong. From Lee FAQ
Oversized bullets
Posted by on 24 October 2011 07:58 AM
There are a few reasons your cast bullets are oversize. 1) There is a nick or burr on the mold face 2) Splash of lead on the mold face 3) No or insufficient lubrication on the mold alignment pins.

A common error with bullet molds is omission of lube on the sprue hold down bushing. This makes it difficult to swing the sprue plate all the way over to the "closed" position in preparation for the next cast, and also tends to force the mold block halves apart, resulting in out of round, oversized bullets. If your bullets are oversized when measured perpendicular to the part line there is a very good chance the mold is not closing all the way due to the lack of lubrication.

Aluminum molds require occasional lubrication. They should be re-lubricated if/when you notice the sprue plate begins to become more difficult to move and/or when the mold blocks do not line up when the mold is closed. Lack of lubrication will cause the mold blocks to mis-align, or the sprue plate to gall the top surface of the mold.

A technique that works well is to have a glob of hard, stick-type bullet lube (like beeswax or Permatex Anti-seize) about the size of a .45 slug rolled into a football; when the mold gets hot, touch one end to the aligning grooves along the sides of the mold block, on the underside of the sprue plate, and on the steel pins along the bottom of the mold block. Use sparingly, as if any gets into the mold cavity it will cause wrinkled bullets.



http://leeprecision.net/support/index.php?/Knowledgebase/Article/View/332/0/oversized-bullets

[Certaindeaf]

The barrel will make them round. The fin line proper is really not measured. Do you lube the locator pins on that mold?

[BenW]

Thank you for the replies.

Looking from the sprue plate, I can see the cavity halves are not lining up. There is full closure, but one half is past the other. I can, while squeezing close the mold, shift the two halves into proper alignment, which is why I think the pins are undersized or the holes are oversized. As a note, there is slop in all directions. For instance I can, while looking from the sprue plate down, move one half farther down, all while keeping the mold fully closed.

Measuring the bullet diameter perpendicular to the parting line measures undersized, while measuring along the split is way oversized. I haven't lubed tis mold since I didn't, until after the problems started, have an appropriate lube (all I had was liquid alox, which is a non-no in the instructions).

I'll try contacting Lee and see what they say.

-Ben

[sandman228]

I had the same prob with a .452-252 swc mold . I sent it back to midway they sent me a replacement it was the same way I sent it back and just gave up on it . to each there own but I do not like lee's new molds I prefer the old and may not buy anymore lee molds because of it . there 6 cavity molds have been this design for quite some time ive only had that trouble with 1 out of about 6 I own .

[garandsrus]

Send the mold back...

[Dan Cash]

Send the mould back for refund; get a quality mould. Lee is the Yugo of the casting world.