Hank, try to get your bore dimensions by slugging/measuring. My step-bro and I tried some Lee 457-340F cast bullets, sized to .451 through a Lee sizer and lubed with my own concoction.We were shooting these in Knight Disc Elites with good to excellent results. Same twist rate as your gun.
They are relatively easy to manufacture yourself but Dan at Bull Shop can surely make them for you at prices that remove much of the DIY incentive. Just email him and be specific aboutwhat you would like to try. Dan might offer/suggest other styles and even make you up a sampler pack for reasonable cost.
http://bullshop.gunloads.com/index.html
Here are some of his bullet auctions so you can see other possible candidates.
http://www.auctionarms.com/search/auctions.aspx?&ad=bullet%20man%20danStick to the .45 cal stuffand I would recommend youselect weights in the mid 300 grain range for that twist.His 45 cal - 385 gn RN Lyman bulletslook like good prospects but I would just about bet he has that Lee mold I mentioned.
He does a great job of casting, packaging, and is willing to work with the individual customer to fill their needs. You would need pure lead, #2 lube, and sized to .450 or .451. I would also recommend some card wads from Track of the Wolf - probably
WAD-460-A (select page 5).
And welcome to the forum.