New N.O.E. 30 XCB mold woes (maybe)

[Cliff]

Received this Alum. 2 cavity 30 XCB mold, just before Christmas. The meplats of the bullets, ends in a vent line. Here's the result.

Do you think that the excess metal on the meplat will cause an imbalance, or, not enough to worry about? This was cast from Lyman #2. But other mixes, like w/w + 2%, do the same.

Next, these cleaned up a little with my thumbnail.

Any thoughts?

 

[Ian]

I wish I knew how to take photographs that were even half as good as yours.

One observation is that you'll probably find that the incomplete band fills will make more difference to flight than the fins on the tips of the noses will, excepting the variances in seating depth that the fins may cause.

Something you could try is switching alloy to 50/50 clip-on WW and pure lead, with no additional tin, and heat treat the bullets to the toughness required by your load. I also notice some nibs from the vent lines all up and down the noses in addition to the fins, which makes me think you're pressure casting, something that should not be necessary at all with that mould. If you make a "natural drop" of the alloy through the sprue plate, angling the mould slightly, and make sure to keep the mould hot enough to fill out the shape of the mould while using the less fluid alloy, that should make for very clean, balanced, accurate bullets. 50/50 alloy is good to about 45K psi and at least 2700 fps in a .30-caliber rifle with a 12" ROT with a good heat treat and month of aging, provided you have all your duckies in a row. Might be good for a little more velocity with a slower ROT to reduce stress on the engraves.

 

[Rick]

I wish I knew how to take photographs that were even half as good as yours.

Want a tip? Take your pictures outside in direct sunlight. Nothing any camera likes better than sunlight, even $200,000 motion picture cameras and their $40,000 light bulbs. For all the compliments I've had on my pictures sunlight is the secret, I am certainly no photographer.
.

 

[Rick]

The flashing on the noses won't cause much of a problem and should flick off with a finger nail. The base of the bullet steers the bullet in flight, not the nose. I would be more interested in seeing how the bases turned out, can't see that in the pics.

 

[waco]

Cliff. That's a good looking bullet there. I looked hard at this mold myself....

 

[Brad]

I wouldn't fret over that little bit of flashing.

 

[Cliff]

Thanks..
The camera is an old Sony Cyber Shot. Not sure about pressure casting. I cast with an old Lyman ladle, full of lead. I turn the mold on it's side, put the ladle to the sprue plate, then quickly rotate up. I'll try the 50/50 with no tin added and at a slight angle and heat treat. If I try to just pour the lead through sprue hole, I get somewhat rounded bases.

As a side note, I just heat treated about 100 of these at 450* for 1 hour and quenched. With the lead alloy calculator, I can always remelt and make something else.

 

[freebullet]

One of my Noe molds did that intermittently. Looked to me like I was having a hard time getting them to close tight enough. I sanded the bushings a scooch & it closed up much easier & no more winged bullets.

My other noe molds close just fine but, I'd still like to see a bit more bevel on the bushing noses. Several more I'd like to get from noe yet.

 

[Cliff]

The base of the bullet steers the bullet in flight, not the nose. I would be more interested in seeing how the bases turned out, can't see that in the pics.

Haven't sorted out any bad ones yet.....

 

[Ian]

Yep, you're pressure casting with the ladle, and that alone can cause finning. The Lyman #2 is very fluid and will fill vent lines if you give it any encouragement via head pressure. If your bases are rounded, most probably your sprue plate isn't hot enough because you aren't pouring enough extra metal over it with the ladle after you fill the cavities.

 

[Rick]

I never inspect bullets while casting with one exception. I inspect the bases, when the sprue plate is opened before opening the blocks is the perfect time see any imperfection in the bases, any rounded or incomplete fill will show up like a neon sign. Any such bullets go straight into the sprue pile, I don't care what the rest of the bullet looks like.

I don't use the Lyman ladle, Rowell is my choice. By continuing to pour alloy over the sprue plate and allowing it run off back into the pot the sprue plate gets and stays hot and the bullets have alloy to draw from as they cool and shrink. Never been a fan of pressure pouring, ladle or bottom pouring. Works for some I guess, just not my thing.
.

 

[Cliff]

Thanks Ian,
In the morning I'll try the 50/50, no tin, the way you suggested.

 

[Ian]

I highlighted some of the things I WOULD worry about, that will affect the way the bullets shoot more than a little nose flashing. The bases look pretty decent, though some might not be perfectly flat or square. Try cutting the sprue before it is quite as hard, and do so with a gloved thumb while pressing down against the top of the blocks with it, that will help ensure that the bases are packed in square and have no sprue bumps.

 

[Ian]

Thanks Ian,
In the morning I'll try the 50/50, no tin, the way you suggested.

The alloy won't fix everything, like Rick and I wrote you'll have to work on your technique a bit (with either alloy) to get perfect fillout and nice sharp, square bases. 50/50 is a lot more difficult to cast with than Lyman #2, but using it will accomplish two things at once: Help you really get your casting technique sorted out and also makes a much more versatile bullet which you can fine-tune in toughness to your exact needs. It is also better behaved at high launch pressure, if you're into that sort of thing. Don't think for a minute that a gas check will mask a base defect when you light the fuse.

 

[Cliff]

WOW! Those defects really show up n the pictures. These bullets are from a different alloy thats been in another pot for a few years. No idea what it is. But, I thought I'd make some with it.

 

[Rick]

Don't think for a minute that a gas check will mask a base defect when you light the fuse.

Exactly yes. I've known a lot of casters that believe if a defect in the bullet is covered up with either lube or a gas check it's not a defect any more. Silly thinking, a defect is a defect is a defect. Matters not if you can still see it it's still there and still a defect and it's most important on the bases.
.

 

[Cliff]

I do need to work on technique. I was casting some NOE 311-299 with 50/50 and got a lot of rounded bands, like the ones you circled. But they, the bands, were somewhat frosted and rounded.

 

[Cliff]

Here is a few of the Lyman #2, sized at .311. I used a Lee push through die. Not all bands are equal on these either, but the bases were good.

These were heat treated at 450* for one hour.
I would say, my technique isn't refined enough.

 

[Ian]

Any particular reason you're making them so hard?

 

[Cliff]

To use in an AR-308 that I just put together. Not sure if they need to be this hard, but the feed ramps scar'em up, a little, on softer bullets.