New Lee molds, no vent grooves?

[fatelk]

I finally bought a couple new molds; a Lee 6 cavity for .380 and a 2 cavity in .30 cal. I've been tinkering with them, getting them cleaned up and trying them out when I noticed something odd - no vent grooves. There are machining marks across the molds faces but they are light and definitely not vent grooves.

When I hold them up to the light together, I can see a sliver of light through them so I wonder if they are just using a new design of some kind. They seem to work OK. I have been having some problems with minor wrinkles but I have some questionable allow in the pot right now. I suspected a very slight zinc contamination until I noticed the lack of vents.

Anyone else have some new Lee molds and notice this?

[Littleton Shot Maker]

I've had several sets of molds from various co.s, Lee, LYMAN, SAECO, magma, RCBS etc. some of the vent grooves were so deep, that if the mold got too hot or the two halves were not up tight I would end up with fine little webs of lead.

Some mold that had no vents grooves depended on the male - female , tab and hole that act like the "spacer" some no matter how hard you squeeze it would not close 100% acting like a vent slit, you only need the hot air to escape the mold as the lead is pour into the sprue plate holes.
Those little tabs can wear down (automated casting machines) with tons of use but you should have made you money back by then.

I should also state for the record. that I have used Lee molds, and won't any more, I have had a few guys give me lee molds made from Al. they went straight into the scrap pile. I will only use Steel Molds now.

[gon2shoot]

Mine have vent lines that look like they were cut with a razor blade [smilie=1: wrinkles went away.

[lancem]

That is the new style, I have several of them in 6 cavity and they work well. The vent is the machined area that you noticed which is unlike the old style line venting. Once you get the mold good and clean and your alloy good I think you will find they cast good boolits. I don't know what Lee uses as a protective oil but it seems to be a bugger to get off well. On my steel molds I just use brake cleaner and spray them off, with the lees it takes more than that to get them clean the first time. Next one I get I'm going to take the comet/toothbrush/sink method and see if that gets it real clean the first time.

[dkf]

The new .380 6 cavity I have does not have any vent lines. I am going to machine some in when I get the chance to. I just feel the fill out is not as good as it should be.

[fatelk]

Thanks guys. I see what you're saying about the grooves. The faces look like they were cut in three strips, and the middle one is slightly deeper, acting as a vent.

I was frustrated when I first used it, in that the bullets were dropping out of round, .358x.360. I found some slight burrs that might have been keeping it from closing perfectly so hopefully that's the problem.

When I sized the .358x.360 boolits to .358, there were slight flats partway up the sides of the nose. This doesn't work so well in the intended pistol.

I should have bought a Ruger! This darn Taurus TCP has a .358 bore and a very short throat. I tried two other Lee designs in it with no success. The 105gr SWC didn't work at all because of the short throat. The 102gr RN had to be seated so short that it bulged the little .380 cases. This new "Ranch Dog" design looks like it should work if I can get round bullets out of it. The one odd malfunction I noticed when I loaded and tried a few rounds was that it jammed on the second round for each of the two mags full I fired. I'm not sure what's going on with that.

[Walter Laich]

I use the toothbrush/comet method followed by a goodly blast of acetone and then kroil. I've been known to put the last two in on hot molds but I'm old and don't have long to live :)
I hear getting them up to temp, letting them cool and repeat a number of times does a good job of getting the oil out.
.
I've had good luck smoking the molds with a kitchen match. This seems to give me good bullets from the start. Only have to do it once as by the time I need/should do it again the oil or whatever is gone.

[tomme boy]

A lot of the old makers never used vent lines at all. I have had a few molds that the lines were completely filled with lead when I got them. They still worked fine. Mold up to temp and alloy up to temp and the right cadence will make very good boolits.

[JonB_in_Glencoe]

I use a fine diamond hone and break the top edge (cavity side) of the mold halves, just a little bit, that adds one vent line at the most crucial spot. I do that on all my new lee molds.

[zuke]

Tried my first one out yesterday, worked like a charm.

[MtGun44]

The machining marks are done intentionally to vent the mold.

Bill

[deerspy]

ok i have a new lee mold 150gr FN and have not cast any bullets yet to cold here, but was looking at it it will not close all the way has three machine cut across the faces
of blocks the top comes together tight but if look in the cavities you can see light every where so I got filler gauge out and you can get .002 in up to the guide pins on each end is this going to work or am I just wasting my time with this mold?

[leadman]

Try it before you condemm it as it will probably work fine. Andy Lee said he is copying some of the methods of plastic injection molding. Do use care with the new very fine machining to creat the vent. I scrubbed one mold with BarKeeper's Friend (like Comet) and a toothbrush and ruined the mold as it wore the metal away. didn't take much either.
I got a new 6 cavity Lee 38 WC TL today and it is great. Andy must have changed back to the flat sprue plate on the bottom and put vent lines in the top of the mold again. glad to see this.
The oil came off the mold easily with brake cleaner from WalMart. I also move the sprue plate out of the way and run hot lead in each cavity for about 15 or 20 seconds letting it overflow into a pan. This seems to either burn or flush out the oils. Once or twice of this and the molds are good to go.