Loads for a Lyman, 452651BV

[Ghost101]

If I may pick ya'lls minds once again. I have cast some Lyman 452651BV , Boolits. Sized and lubed with "FelixLube". I'd like to fire these thru two different guns. 1) Ruger Vaquero, early heavy framed , an 2) Bushmaster .450.
I haven't been able to find any load date for cast boolits for the .450. The "Lyman Cast Bullet Handbook", 4th edition, only has a load for a Saeco (Redding)#454, in 300 grs. Different profile altogether. My boolits with the GC weight in at 344 grs., without they are 330. The hardness on these is 25-36 BHN on the LBT hardness tester. They have sat under my reloading bench since last winter. It's taken me awhile to set up my lubersizer. Just with that statement you know I'm fairly new at all of this. All other boolits cast an shot up to this point have been TL an sized with Lee's unit. The book says, with a 300 gr. boolit for an example; Unique at 4.8 grs - 6.1grs, for fps of 628-764 an pressure up to 13,900. I suppose thats for a Colt or one of the many SAs of it's design.

What I need is a loading for these two firearms with this boolit. But thats not all. I would like to know how ya'll get to that number. I must admit that my math skills are poor to say the least. But I do have friends with the ability to work out stuff for me.

Thank You once again!

[dondiego]

I'd start with 7 grains of Unique for the Vaquero. I use up to 9 grains of Unique in my Vaquero with a 250 gn. boolit. For the .450, use the starting load data for the Saeco boolit.

[runfiverun]

for the vaquero it's pretty simple the gun itself has a pressure limit and you can go up to it's designation the load books will show different "colt" loads.
you can go from or up to there with the lower pressure loadings, i just look for a load that is fairly accurate and comfortable to shoot.

for the 450 i'd start by making a dummy round and checking fit and function.
then working with known data [if it's for a lighter bullet] i'd have to reduce the load based on case capacity reduction and err on the side of caution working with just a few rounds at a time.

[Ghost101]

I suppose that a filler should be used. I haven't use a filler in smokeless powers, only COW in BP pistols.