45 Colt loads for Rolling Block Rifle

[Miseryguts]

Hi, Always fancied a Rolling Block single shot rifle, and am shortly to be the proud oner of one in 45 Colt calibre (not ideal I know, but allowed at all my clubs from 50 to 200m, and I have all the kit and materials to reload that calibre anyway).

So, it is a Pedersoli, and does any one know what the proof pressure in these is? Is it 14000 as per SAAMI, or 15900 as per Pedersoli download, or anything from 19000 to 30000 as per some powder manufacturers?? (cup/psi by the way). I would like to stretch it to 300/400m on my own ground, but really need to get the MV up a bit to have a reasonable chance of hitting anything other than a barn door, which would be difficult at a "do not exceed" of 14000.  With Unique or Blue dot the MV would be around 1100 to 1200 fps, whereas I would like to be looking at 1300 to 1500 or possibly more with a jacketed bullet?

M (dreaming in Monmouthshire)