Sizing die question

I have just started casting using a lee mold for 500 grain .459 bullets for my custom built High wall, the barrel is a Green Mountain with a bore of (this was checked for accuracy) .458 across the grooves. I decided to buy a Lee sizing die and lube kit but all they have is a .457 die, what the dickens is a .457 good for? Maybe I am missing something but would .457 be too small for a .458 bore? The few bullets I have cast so far appear to be .459 but they are not perfectly round, being out-of-round by nearly .001, and so I thought a sizing die and lube kit would produce lubed bullets and at the same time correct the slightly out-of-round problem. I tried .458 cast bullets from Midway in my 45/70 Marlin but accuracy was poor so a friend suggested I try a .459 which turned out to be far better even though it was the same weight. Thinking the same may be true for the Green Mountain barrel since it slugs almost identical to the Marlin I just fail to see the use for a .457 slug. Why size down to .457 am I missing something?

I don't know off had but I'm sure there are some guns that use .457. Lee will custom make you any size you want for like $25 or Buckshot here also will make one for you. I personally would just shoot it as is. It will round out as it travels down the bore of your gun and .001 out of round is no big deal.

What is the diameter of the as-cast bullets? If not excessively large, do what I do. I shot as-cast.
You can pan or tumble lube. You can order a custom sizing die that is the same as your as-cast diameter or whatever size you think is what you want (you will most likely do best with 0.459-0.460" bullets, though larger bullets, as long as they chamber, will be at least as good).

oldred, You may need a .459" or larger cast bullet. If so, you can easily lap out a .457" Lee sizing die to .459" - .461" as per Buckshot's tutorial: http://www.castpics.net/subsite2/How...Size%20Die.pdf

Ok I ordered the lee .457 lube and sizing kit, I never even thought about honing it out but after thinking about that suggestion I can see where that should be simple enough. Thanks

I had Lee make me a .459" sizer for .45-70 as well as a .380" for .38-55 for my Hi Wall and Rolling Block.

Shoot em like they drop - your barrel is the perfect sizing die.

Wes