.45-70 bullet size

[GH1]

 I'm going to order some non GC cast bullets to load for my Handi, and I've only found one vendor that will offer a bullet sized to .459", the rest are .458". I'm looking to shoot a 405 gr at around 1300 FPS or so.
  I was always under the impression that cast bullets need to be a little bit bigger to prevent leading, if so, why do so few companies offer them?
 I've not slugged the bore, do I need to worry about leading with .458's?
GH1  
 

[Lloyd Smale]

most of my guns prefer .459-461 but give the 458s a try they might surprise you. Mine do better with the larger sizes but still do respectable with 458

[anachronism]

It's kind of like buying shoes by mail order. You need to know what fits. One companys size 12 might not be the same as another companys size 12. So you need to measure your feet, determine if you need a wide or narrow fit, and order accordingly.

[quickdtoo]

Give Western a call, I've ordered bullets as cast(unsized)from him before, I'd be willing to bet many cast bullet mfrs will if you ask, there's a list of mfrs at the top of this forum. I know Chey-cast has .459" 405gr, and Montana has 400gr .460". But I'd follow the advice you were given before, do a chamber cast or check a fired case to see how big a bullet you can chamber, if you can't chamber it, there's no sense in ordering them.

Tim

http://westernbullet.com/45riflecaliber.html

[GH1]

 I just ordered some .459's from Missouri Cast. I have some 150 gr collar buttons from Western that I loaded with Trail boss but I've yet to fire them. I didn't much care for the overabundance of red lube on the bullets, it was a real pain to clean out of my seating die.  It'll be awhile before I get a chance to fire them, given the fact my gun is at the Handi plant being fitted. As soon as I'm able I'll get to the range and post a full report.
GH1

[Missionary5155]

Good morning
1st item to find out is what diameter is the throat area in your rifle.  If the throat diameter (not the groove diameter) is .459 (I would be surprised) then a .458 PB bullet may be a futile attempt at accuracy.  If my rifle measures .460 at the throat I am going to use that figure as minimum and size my cast bullets to .461.  .460 may be OK but will be a fringe minimum.
With PB bullets you must seal the hot gasses behind the bullet or that hot flame pushing past the bullet base is going to cause you problems.  Think of that bullet as a piston in an internal combustion engine.. Hot gas blowby is no ones friend.
That is why many cast bullets are GC types.. that copper disk is going to be very effective at sealing the gasses behind the bullet but again only if it is the proper diameter. 
Mike in Peru

[GH1]

I not familiar with the term throat, is that the same as the chamber? Or is it an area between the chamber and the actual bore?
GH1