Smashed lube grooves

[abunaitoo]

Since there is no lube when PCing, how would it be if a boolet was sized enough to smash the grooves????
Just wondering.

[sureYnot]

If you're talking about ending up with something like this, it should work swimmingly.

[Dragonheart]

The only purpose I can see for a lube groove on a PC bullet is a place for the extra metal to go when sized. Eliminating the lube grooves completely I would think you are now into swaging. As long as you can maintain a flat base on the bullet and it is to the size you need for the barrel, why not?

[popper]

As Dragon points out, only problem is all the Pb displaced by the bore/lands goes to the base and gives fins. May or may not cause a problem.

[NoZombies]

The only issue is concentricity. unsupported bullets can get lopsided as they're pushed through too small a die. It's especially easy to see on long rifle bullets. I don't have any photos, but imagine a mildly banana shaped bullet...

[fredj338]

The only issue is concentricity. unsupported bullets can get lopsided as they're pushed through too small a die. It's especially easy to see on long rifle bullets. I don't have any photos, but imagine a mildly banana shaped bullet...

^^THIS^^ Depends on the bullet casting round but if it is at all oval, then you get a weird distribution of displaced metal around the bullet as it is sized concentric. I would think it would take a lot of sizing though.

[NoZombies]

^^THIS^^ Depends on the bullet casting round but if it is at all oval, then you get a weird distribution of displaced metal around the bullet as it is sized concentric. I would think it would take a lot of sizing though.

Yes, also the slight misalignment of punch and die can make the sizing non-concentric.

[wrinkles]

Wouldn't it be simpler to remove the bands from the mold?

[Dragonheart]

Actually, if it is a cast bullet it is already not concentric when it comes out of the mold. Take your best effort and roll it with a dial caliper and watch the needle jump. This is physics of the process and has nothing to do with the skill of the caster or the or quality of the mold.

When the liquid metal in the mold is cooled it is constantly changing diameter from thermal expansion. When you open the the mold part of the alloy is exposed to room temperature while the rest is protected so the roundness is compromised. The halves of a mold cannot be put together with zero tolerance, so this adds to the problem; end result non-concentric (lopsided) bullet.

Sizing only makes the band round and does nothing for the bullets nose, so the bullet remains non-concentric. Doing nose sizing as a separate step as in the NOE system will make the nose round, but like laying a nickle on a quarter they are both completely round, but that does not mean they are concentric, so the bullet remain non-concentric. I think the ultimate answer is swaging; reforming the bullet completely in a single step to make it concentric. We have discussed this before, but to my knowledge no one make a mold & swage die combination that would bring casting and powder coating into a new era.

[Phantom30]

Fine turning castings with a CORBAN swage is expensive, and the punch is just as important as the die. Plus then you have pre and post PC dimensionality to work, doubles cost. Unless you are planning to make precision cast bullets for a post apocalypse army, just buy more factory bullets.

[NoZombies]

I think the ultimate answer is swaging; reforming the bullet completely in a single step to make it concentric. We have discussed this before, but to my knowledge no one make a mold & swage die combination that would bring casting and powder coating into a new era.

An adjustable core mold is sufficient, since the swaging die will do the work of giving the bullet it's shape anyways. I've messed a lot with PC'ing a core and then sawging it. It just plain works.

[P Flados]

Hmmmmm,

kinda like



I like the idea (and the results).

More info was posted previously in other threads.

This is actually a "bump up" sizing with a low-tech made at home "forming die" that is similar to swaging but easier & cheaper.

[Phantom30]

How do you maintain a G1 BC >.4 nose shape with your process?