John Y Cannuck said:
Try
http://castboolits.gunloads.com/
This is the main cast bullet group on the net near as I can figure.
This list (
http://sports.groups.yahoo.com/group/CB-L/ )has been around much longer (there is some cross membership) and was the unofficial site for CBA members (
http://www.castbulletassoc.org/ ) before our own forum was put in place (
http://sports.groups.yahoo.com/group/cbaforum/ ), so there is a much large archive to pull loads from.
Generally there seems to be no need for speed in the 45-70 as general experience is that any 45 projectile will completely penetrate any animal it hits
I'm happy with the load I pulled out of the book by Paul Matthews,
Fourty Years with the .45-70, namely RCBS 45-300-FN over 32 grains of 2400 that I use in my Marlin 1895G which in this short barrel gun chronys at 1800fps plus or minus. I have a bump die that just happened to be bang on for this piece. I have other moulds which I haven't got around to try simply because I had a previously cast supply of the 300FNs for my 45-90.
In avoiding leading, bullet fit is more important than hardness. A soft bullet which will not allow gas cutting around the base of a bullet will work much better than a hard bullet which is gas cut thus leading the bore.
Commercial cast bullets are often made from linotype because using this material they can supply a consistant product in terms of weight and appearance but if the finished product is not the proper fit for your particular barrel you will join the legions who claim cast bullets are no good. You should cast your own and fit them to your gun.
While I have a good supply of linotype I feel it is wasted in the big bores which were designed to operate at 1300fps (1600fps express). These old slow velocity cartridges have taken more game than any of the modern speedsters so I feel comfortable in the original design range especially in the old guns.
Yes the new guns such as the Marlins will take more pressure but then you're looking at cartridges designed for black powder which have excess capacity for smokeless powder unless you go for a case full of surplus airplane cannon powder and the headaches that can develop such as duplex loads to avoid unburnt powder interfering with chambering or consistant accuracy.