Originally Posted by
robert12345
Humm....
Folks seem to think that the limiting factor in getting high velocity, ...with accuracy, when using cast bullets, ..is the lube.
Nope, it ain't the lube....
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The limiting factor in high velocity, with accuracy, is the lead alloy.
Lead is soft, the push generated by the exploding gunpowder, ..is a heavy fist, of fast quick force !
That fist of explosive force, hits the bullet base first, and it hits the bullet's .......front ...last.
The base of the bullet, accelerates, before the point.
Lucky for us; the base flattens out, filling the throat, and the bullet's nose then slumps, filling the bore.
And the overall result is an accurate shot leaving the rifled barrel.
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A pointed cast lead bullet has vastly more airspace around it's nose, "to slump" than a round nose bullet.
That is why pointed lead bullets are notorious for being inaccurate. ( They exit the muzzle bent at the point. )
To shoot a pointed lead bullet accurately, we must cast them very hard, then use very light charges of fast burning powder.
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If accuracy at velocity is what we want, we are limited to round nose bullets, rather than pointed lead bullets.
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A study of bullet lubes is fine, but if you want high velocity with cast bullets, and you wish to use a pointed bullet, then you need to cast the bullet a hell of a lot harder than we can at home, and/or, we need a propellant which gives the bullet a long slow push to high velocity.
We in our home work shops, do not have the technology to make bullets hard enough to make them shoot fast, and there are apparently no powders suitable for a long slow push needed for gentle launches to high velocity in cast bullets.
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In the long run, unless technology changes, we are pretty much limited to 2200 fps.