Hair brain idea or Doable ? You decide

[standles]

Ok folks here goes.

Looking at a 45/70 bullet design similiar to a postell.

Make the mould nose pour
Have the bottom open so a plug (similiar to a hollow point plug but would be flat topped) can be insterted.

This would index off the lube grooves

Depending on how far I inserted the plug I could get mulitple grain bullets from the same mould.

Ex. (toitally made up numbers)

1 groove 600grain
2 groove 500grain
3 groove 400 grain
Etc.


Is this doable/adviseable? I assume at some point your going to be to short on the bullet and the CG will be off causing tumbling.


Your thought?

Steven

[45 2.1]

Barlow/Lyman did it about 100 years ago. It was called a perfection mold available in nose pour designs.

[snuffy]

Do-able maybe, practical-I doubt it. Positioning the bottom plug would have to be precise, as would the fit to the driving bands. Or else the boolit would have fins on the base. The there's the expense for all that precise machining. Sounds like a project for a tool&die expert, who's also a boolit caster!

[Morgan Astorbilt]

Definitely doable. Below, is an adjustable .334 nose pour mold made for me years ago by fellow schuetzen shooter Frank Zika, for my re bored 8/15x46R Aydt schuetzen rifle. It's a copy of a DWM hollow base design popular back in the golden days of schuetzen shooting in Germany. DWM used to market these bullets, wrapped individually, complete with a primer and powder charge. Frank made it based on a Cerrosafe chamber casting I furnished. Don't know if Frank is still making molds, the last time I shot with him, he was making high quality tang and front sights.
Morgan

[jtaylor1960]

Some of the custom mold makers still make adjustable nose pour molds.They could be handy for fine tuning a gun by varying the bullet weight while maintaining the nose profile and fit to the chamber.

[standles]

Thanks for the info.

I have a couple of aquaintances that are machinists. Maybe I can invite them over for a cookout, get a few beers in them, show them my sketch idea, and then say "aww never mind you probably couldn't machine something that complicated anyway.




Steven

[Bullshop]

I am trying to get a pic of one posted for ya but am having trouble with photobucket. God willing it will get done.
Blessings
BIC/BS

[Bullshop]

Here ya go

[Bullshop]

This is a Tom Ballard mold in 40 cal. Its hard to see the adjuster plug on the right. It is adjusted for a 280gn(three drive bands) boolit as is and will go up to about 450gn. Tom does good work.
Blessings
BIC/BS

[beagle]

It is doeable and from either end. I made a adjustable nose on a 358315 and it holds position very well (see 358315 modified in articles on Castpics).

Just a new rerun on the old Ideal perfections. Only problem with them is I can't get one.

It would be possible to do that and have a GC design as well./beagle

[45 2.1]

It would be possible to do that and have a GC design as well./beagle

You need to run that by your machinist if you want to adjust the GC end............................

[Morgan Astorbilt]

A GC should be no problem. You remove the base pin before opening the mold anyway, so the base pin can have the cavity for the reduced OD GC seat. If this is tapered, there's no problem with the GC's falling off, even if they're not crimp-ons. Lube grooves aren't necessary for the full length of the bullet, so the bottom of the cavity and the pin can be smooth, and the cam latch as on mine used, allowing infinitely variable bullet weight, and no need to take care to put the pin in the right lube groove.
Morgan

[beagle]

Morgan...right on brother. Normally, the adjustable portion must have the old Cramer setup where the adjustable portion is attached by a screw and allows that portion to flop free and release the bullet when the mould is opened. Not a problem making a GC'd adjustable base mould./beagle

[seppos]

Definitely doable. Below, is an adjustable .334 nose pour mold made for me years ago by fellow schuetzen shooter Frank Zika, for my re bored 8/15x46R Aydt schuetzen rifle. It's a copy of a DWM hollow base design popular back in the golden days of schuetzen shooting in Germany. DWM used to market these bullets, wrapped individually, complete with a primer and powder charge. Frank made it based on a Cerrosafe chamber casting I furnished. Don't know if Frank is still making molds, the last time I shot with him, he was making high quality tang and front sights.
Morgan

That looks nice expesially as ogive fits my rifle troat, there is deep generous lube grooves and that it is single mold.

S

[Ballistics in Scotland]

As has been said, it is an old, albeit mostly now-forgotten idea. The most complicated bit of the machining would be to have the plug held by an annular ridge in the lube groove of your choice, and that isn't necessary if you have the moveable base plug (or moveable nose in a base-pour mould) accurately located in some other way, even when you are casting a lot of bullets quickly.

Morgan's would be accurately located by the interrupted flange for one of its bullets, and it looks like the stud can be moved to different heights by loosening a locking screw. You could have two or more of those locating studs in the bottom of the mould, into which the flange could lock at different depths.

You could also have the plug screw into its hole. You would only have to trap it within one thread of its intended position in closing the mould, and then if a rotational index mark is matched up, its height is very accurately located.

If the threaded hole is considerably larger than the bullet, it could be located considerably more in one half of the mould than the other. Then it would stay in place as the mould is opened and closed. If you are making your mould from scratch, it would even let you dispense with locating pins. Of course you would have to do without the rather attractive little concave base Morgan's mould provides. But I don't see much harm in that.

[Scharfschuetze]

Wow! This thread was started over 8 years ago.

Anyone wishing to do what the OP originally posted about should contact Dave Farmer at Hoch Moulds. If anyone can do it, he can. He's the consummate mould maker and my most accurate 30 cal mould came from his shop 30 years ago when he bought the shop from Richard Hoch. The Hoch nose pour design would be most amenable to your idea.

Here's the link: http://hochmoulds.com/

[Harter66]

Accurate does the moulds but requires a 3rd party for the base pin.

[runfiverun]

it seems multiple pins would be the way to go.
just stick in the 350 pin and pour, or the 400 pin and go.
the gas check shank could be cut into the pin.

[popper]

Interested in a nose pour mould as I shoot a lot of flat PB for rifle. Seems like this could be done with a 4 part mould, CNC tooled. Bolt/pin the top/bottom quarters. Makes sense as the base steers the boolit but doesn't make much sense for pointy ones. GC bases are easy to pour good so doesn't really apply either. Due to expansion IMO steel would be the material to use.

[Buckshot]

Not a bullet mould, but rather a 'core' mould I made to create cylinders of various weights for swagging into slugs for paper patching. In the left photo the center cavity has a core in it.



The principle is the same, but of course for a GG bullet the pins would have to be set to co-incide with the drive bands.

..............Buckshot