You have to answer that question. First, let me give you some information from Alpha Precision's web site:
"When cast bullets are used, the bullet should be .0005 to .0010"larger than the barrel groove diameter. Ideally, the cylinder throat will be .0005 to.0010" larger than the bullet. To illustrate, Douglas .44 handgun barrels typically have a groove diameter of .429". The cast bullet should be .4295 to .4300". The cylinder throats should then be .4300 to .4305"
You will also note that Beartooth's bullet selection for the .44 240gr. bullet has 5 different diameter selections. These optional bullet diameters are not based on the manufacturer of the gun, but the groove diameter of your particular gun. You can try each diameter by process of elimination or you can "slug" your barrel to determine it's specific groove diameter and then apply the information from above. You can buy a kit for slugging your barrel or purchase Mr. Stanton's "Tech Guide" (see Beartooth home page) that will not only tell how to do it, but the cheapest method/material to use. The price of the Tech Guide with it's recommended material will be cheaper than the kit and you'll have a document that offers a lot of other information as well.
Hope my poor explanation isn't too confusing and helps a little,
For myself, I load only for a mod #24 S&W, in the 44 caliber family. How ever I've loaned my molds, press and loading books to some friends, who felt the need to make loud noices with their 44's.
So, out of several load developement projects I've not found one that did not like .430 or .435. Each of these revolvers had been lapped, to remove the frame/barrel constriction.
Arkypete makes a very good point in referencing having lapped both guns to remove frame/barrel constrictions. Lapping and it's advantages are covered on this site in other posts and covered in detail in the referenced Tech Guide. I realize my response may have been more than you were interested in, so I'll close by saying that the majority of my nine .44's use .430.
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