Why two different mold diameters for one caliber?

[Diesel]

Newbie question here: I just bought a two cavity Lee mold for a .44 MAG. I noticed that they offer a .429 and a .430 diameter mold (dependant on bullet style and weight). I only planned on buying one sizing kit for all of my .44's. Do I need to buy two; one for each casted diameter?

Thanks in advance for any help!

[high standard 40]

It is suggested that you size your cast bullets .001" over bore diameter. The 44mag is supposed to be .429 bore and would require a .430 cast bullet. Of course the only way to be sure is to slug your barrel. I size mine .430 and they shoot fine. I have a Lee mold in 214gr SWC and I had to lap the mold to get it to drop bullets of a diameter I could use. It was dropping .4285 from the factory. It now drops bullets .4315 and I size them to .430 and they shoot well.

Charlie............

[Willbird]

Just a guess, is one mold a tumble lube and the other a grease groove mold ??

Bill

[missionary5155]

Diesel... Greetings and WELCOME !!!
Then there are other calibers that use so called 44 boolits.. like 44.40 44 special 44 Russian.
The 44-40 may have throats .427 up to .429+.
44 Russian may have .428 and past .431.
So manufacturers have a habit of listing ALL the possibilities their mold may work for.
Try some boolits cast from your mold. Maybe they are FAT enough to fill the throats of each cylinder. Try to push a boolit through each cylinder/ throat. Hopefully they get stuck in the narrow end (THROAT) towards the barrel or at least be SNUG. Also see if they are fat enough for the barrel.
BUT what you need to do BEFORE buying molds is measure the throat size and barrel of your revolver. The boolit needs to fill the throat at ignition or hot gasses are going to blow past the boolit base and cause you problems. And not all the throats on the same revolver may be the same. The barrel MAY be larger diameter than the throats ...Bad. So I would measure and get a mold that will be .001 larger than the widest throat.
There are simple solutions also if you already have a TOO small mold. You can open a mold up SEARCH "Beageling a mold" . This is an easy solution.
Yea just starting out can be problematic... but you are headed right by ASKING FIRST. I trust you like to read....
God Bless you Mike

[Diesel]

It would appear that you are all correct! Thank you for the help. Time to read more on this little obsession of mine...;)

[Buckshot]

..............."I only planned on buying one sizing kit for all of my .44's. "

Gee, wouldn't THAT be nice :-) Of course I don't know how many 44's you have so maybe one will do. As previous posters said, it's up to the gun what it wants or refuses to do well with. One rule of thumb that's kind of universal to get you headed in the rigth direction anyway, is to slug the barrel first, and with a revolter to also slug or use calipers on the chamber mouths.

Hopefully the chamber mouths will be the same as the groove or even a bit larger. Bad news the other way around. Then if they'll chamber with room, size the boolits a thousandth OVER the chamber mouth.

Oh yeah, welcome to the board too!

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

[44man]

Some .44's have smaller bores. You need to slug your gun and measure it. Most S&W's will have a .429 groove to groove and Ruger's will have .430. But they vary a lot.
It is still best to go larger as long as a round will chamber. You should fit the boolit to the throats instead of the bore and the throats should be larger then the bore.
A .430 will be right for the S&W and .431 to .432 for the Ruger.
If you are lucky the mold will drop larger boolits then listed and you can shoot them without sizing unless they have a gas check. The check needs crimped but you can just put it in a sizer far enough to do that. Use a size die the same size as the casting drops from the mold.
Like Mike says, they make .44 molds for other then the .44 mag. Stick with the largest.

[EDK]

Just to make things more interesting, the very popular MARLIN 1894 44 magnums usually run closer to .432. Ranch Dog, our resident boolit designer specializing in MARLIN rifles, designed his excellent tumble lube boolits to run .432 AFTER sizing and installation of gas checks. Since I'm casting and reloading for 3 MARLIN rifles, assorted RUGER single actions and Smith & Wessons, I chose to size to .432.

:cbpour::redneck::Fire:

[Bret4207]

Just get the biggest one they offer, it'll stand a better chance of working than a smaller one.

[mtgrs737]

Just to recap what the others have already said, slug the bore and the cylinder throats. Cylinder throats should be .001" or greater over the barrel groove diameter for best results. Shoot as cast or size to cylinder throat or slightly over size as long as the loaded cartridge will slide into the guns chamber. Too tight of a fit in the camber caused by a boolit that is too large can raise pressures upon firing and cause an unsafe condition.