What happened to the nose-pour mould?

[Spindrift]

So, I’ve pondered this a while, and I just don’t get it.

Premise #1: It is a well described fact of ballistics that uniformity at the base of the bullet is more important for accuracy, than uniformity of the nose. This is reflected in the design of open tipped match- bullets.

Premise #2: when casting bullets, the part of the bullet that faces the sprue plate, is more likely to have geometric variation, than the other end.

Premise #3: The part of the bullet carrying the sprue cut is more likely to have a porous structure, making it more likely to change shape when exposed to a certain force.

When considering these premises, it seems abundantly clear (to me) that all moulds with flat noses should be nose-pour moulds. To do otherwise, would be to put the weakest part of the bullet where strength is most important- and accept unnecessary geometric variation where it is most harmful.

But there are, to my knowledge, no nose-pour moulds in current production.

So, guys. What happened to the nose-pour moulds?

 

[Ian]

Hoch makes them, I have one and so does Ben.

I've wondered the same thing, particularly regarding round/flat nosed or truncated cone handgun bullets which could easily be either lathe-bored or cherry-cut like normal base-pour moulds.

Pointy-ish rifle bullets make the mould necessarily more complex due to machining limitations. The moulds must have either a second "sprue" plate on the bottom so the mould can be bored from that direction, or have a spud similar to a hollow-base spud fitted for the same reason. Removable spuds and base plates introduce geometric and thermal variations which, in essence, make their would-be advantages more or less a wash.

 

[Charles Graff]

I have an old El Paso made NEI nose pour clone of Lyman 31141. It cast .310 X .301 from ACWW. Darn good mold, but not much more accurate that base pour versions.

 

[Bret4207]

I've got 2 Hochs. I've yet to run any tests. No time.

 

[RicinYakima]

The issue is the cherry to cut the cavity is weaker and breaks more often than the thicker shank of the base. HTH

 

[RicinYakima]

Hoch and Pope don't have that issue because of two plates.

 

[popper]

Exact reason I do my PB rifle as a really short GC shank mould. Very crisp or easy to cull base.

 

[Spindrift]

Thanks for your repiles!
Didn’t think about the machining limitations- it makes a lot of sense.
Learned something today.

 

[RBHarter]

My PB/HB M-P is a nose pour also as well a a couple of Minie' balls ..... Lee even makes a couple .

Your premise is correct . There is the matter of the nose being the thin part of the mould RB moulds are pretty easy to mess up . And there's the tangical sprue .....

 

[L Ross]

There's a Hoch around here somewhere. A 175 grain .30 caliber. The bullets shot from that single cavity mould grouped just as well as the .312-155-2R from my $19 Lee two cavity but were more tedious to cast. A distinct loss of interest followed.

 

[Rick]

I have that mold also. Haven't touched it in 25-30 years. It has what amounts to two sprue plates, top and bottom and greatly complicates getting mold temp correct. Once you get that figured out it casts a fine bullet but I too lost interest in it.

 

[L Ross]

I have that mold also. Haven't touched it in 25-30 years. It has what amounts to two sprue plates, top and bottom and greatly complicates getting mold temp correct. Once you get that figured out it casts a fine bullet but I too lost interest in it.

Maybe if we were shooting Pope false muzzle, breech seated Schuetzen rifles it might be worth the extra work of making nose pour projectiles, but I doubt it.

 

[RicinYakima]

Maybe if we were shooting Pope false muzzle, breech seated Schuetzen rifles it might be worth the extra work of making nose pour projectiles, but I doubt it.

I have two Hoch moulds; one is a .510" for my 50/70 Rolling Block and 50/70 C. Sharps Arms 1874 and the other is a .462" that is a great target bullet for the Trapdoor. An hour casting with either one is a five year supply of bullets.