new to casting lee 457-450 casting heavy!

[harryman]

I'm new to casting and need help ! have a new lee double cavity 457-450. It is casting heavy, 460gr-465gr . I'm using wheel weights from work for ingots I don't think any zinc got mixed in but any thing can happen. any suggestions?

[338RemUltraMag]

This is normal, my RCBS 30-180-FN is suppose to be 180 gr but it casts out at closer to 195. It is what it is in the mold world. And as a side note Zinc would leave your boolits lighter not heavier, that is why they float in the melt

[Bullshop]

Why would it be a problem?

[harryman]

It's not a problem just wondering if its normal for a mold to cast that much heavier than advertised.

[btroj]

The weight is dependent upon alloy, actual cavity diameter, and cavity depth. Small variations in the actual size of the cavity coupled with a different alloy than it was spec'd with means a heavier bullet.
Ignore that. Just load it and shoot it. The gun will never know the difference.

[harryman]

that was my plan just to shoot them. their just for plinking anyways, the mold is a little small for my gun at .457 but it was free a.459 would be more suitable .

[btroj]

Do they drop at an actual .457? Does your barrel slug at .459?

If those are the actual measurements you could easily have a leading machine there.

[harryman]

yea it drops .457 and the barrel is .459 . Im gonna shim the mold to try and get it .459. the ones I have cast I'll just put back in my pot .

[oldfart1956]

If the beagleing (shimming) doesn't suit you harry lap that bad boy out. These Lee molds are soft enough I could lap one with bacon grease and table salt! :) Seriously. I've lapped my Lee .459/405gr.hb out to where it's dropping Lyman #2 at .465 and then I size them down to what I want with a modified Lee sizing die. And the boolits are dropping rounder than when I first bought the mold so yes it can be done. Adding a little tin (lead-free solder) to the alloy might gain you a little in dia. (better mold fill-out) but I doubt it'd be enough. I had to do it...Trapdoors bores tend to run large. Audie...the Oldfart..

[harryman]

will try lapping I have some fine and medium compound . thanks for the info

[Bullshop]

To answer the question, yes it is normal and will very depending on the alloy content.
To address the under size issue, cast in a soft alloy not exceeding about bhn-8 and use a relatively fast burning powder not slower than 2400. The soft boolits will bump up and make the gas seal just as they do in muzzle loaders (bore diameter not groove diameter) shooting conical boolits.
I shoot .458" diameter boolits from a Trapdoor with a .462" groove diameter barrel with excellent accuracy and no leading.
The load I shoot most often is 21gn 2400, with a 520gn rnpb boolit and packing popcorn filler.
I shoot the same load with a 500+gn paper patch boolit patched to .451" diameter which is about bore diameter not groove diameter.
For these loads I use boolits cast in pure lead or alloyed to not over bhn-8
For this to work I have found two points critical, the alloy hardness and the powder burn rate. An alloy harder than about bhn-8 becomes iffy and a powder slower than 2400 has the same effect.
Stay within these guidelines and the actual diameter of the boolit is not that important. It can be anywhere from bore diameter or slightly under to groove diameter or slightly over and still deliver very good accuracy free from leading.

[harryman]

the problem with powder is my gun is a bfr in 45-70 with a 10" barrel 4759 is the only thing I have found that is accurate thanks to 44mans advice. Like I said I am new to casting and cast boolits the info from the guys on here has been great I'm glad to have found this sight. thanks to all that have helped with my journey so far.

[Bullshop]

OH! Sorry I didn't know we were talking revolver.

[JeffinNZ]

I thought RCBS specced their moulds on linotype. That would be why they cast heavy.

Advertise it on Ebay as a 'limited run, custom mould cut to throw extra heavy'........

[warboar_21]

I have the same mold and mine drop at .457" as well. When I weighed mine they were closer to 455 average wt with wheel weight alloy. I tried shimming mine and the first results are about .459". My bore is 457" so I don't know if i'll bother sizing them or not.
I think I will try lapping it as well since the bullets are a little out of round with the shimming. I think if I added more high temp tape and then sized down it would be more uniform.

[338RemUltraMag]

I thought RCBS specced their moulds on linotype. That would be why they cast heavy.

Advertise it on Ebay as a 'limited run, custom mould cut to throw extra heavy'........

I dont find it a problem, I load em and shoot em and never gave it a second thought.