Bullet Mould Question

[Mixed Nuts]

Researching bullet casting and cast bullet shooting for the .357 magnum - thanks High Road - I've come to understand a few things about cast bullets in revolvers.

Thing one - It's better to have bullets sized slightly larger than cylinder throats.

Thing two - it's better to have cylinder throats that are slightly larger in diameter than bore size.

Considering the above and the .358 reamer diameter of the Manson throat reamer, one can't help but notice that most .357 bullet moulds are described as throwing .358 sized bullets.

Yet .359 would be ideal for a .358 throat and .357 bore.

My question is: Do the moulds described as throwing .358 diameter bullets actually throw larger diameter bullets? They must, right? I see .359 sizing dies but seldom do I see .359 or .360 bullet moulds.

 

[jaguarxk120]

It all depends on the alloy you are using. Some will cast larger bullets and some alloy's will cast bullets on size or smaller.
What counts is how your gun shoots with those bullets and lube combination.
For the most part follow the Lyman cast bullet handbook.

Now if you really want to have fun start using cast bullets in a rifle, now that's fun.
Some loads will shoot like bench rest and some will shoot like a shotgun.

 

[243winxb]

Most do with the correct alloy. Molds are regulated by an alloy the manufacture picks. The higher % of antimony in the alloy, the larger the cast bullet will be.

Lee 95% Lead / 5% Tin mixture. . Lyman has there own #2 when i started casiting. Saeco alloy (2% tin, 6% antimony, 1/4% arsenic, 91.75% lead). Lyman 45acp mold drops bullets at .452" . My Saeco 358/158gr drops at .360" i have to add linotype to ww/scrap lead to make the .452" diameter. I avoid Lee. RCBS makes good molds in 2 cavity, sold mine to upgraded to a 4 cav.



Bullet Sizes & Weights – How to Vary Them. http://www.redding-reloading.com/online-catalog/88-bullet-moulds-charts

 

[Walkalong]

Thing two - it's better to have cylinder throats that are slightly larger in diameter than bore size.

Considering the above and the .358 reamer diameter of the Manson throat reamer, one can't help but notice that most .357 bullet moulds are described as throwing .358 sized bullets.

Yet .359 would be ideal for a .358 throat and .357 bore.

A tight slip in the throats is good enough almost all of the time. So, .358 is fine for a .358 throat.

Unless you are using way to hard an alloy for the pressure even .357 in a .358 throat can work since it will bump up under pressure and seal the throats.

A .358 bullet in a .358 throat for a .357 groove diameter is generally fine.