Has anyone loaded cast bullets for a 416 Rigby, I picked up some 370 grain cast bullets and haven't been able to find any useable loading data.

Try ~50 grains of IMR-4198 and see how those bullets perform. I cast roughly a 370-grain GC'ed bullet for a friend who has a Rigby and that is his load. The only thing I can't tell you is where he has the COL set on his rifle. I don't know if the bullet is up tight against the lands (which in my estimation it should be as cast typically don't like to jump) or if it is slightly off.

Send Bnagel a PM and ask him. He posts on here...

I was loading a cast bullet in the 404 Jeffery and depending on the alloy (I cast different alloys for different purposes) it weighed from about 350 to 375 gn and a 21.5 gn red dot load gave me great plinking load at about 1400fps.
63 gn H4350 gave a superbly accurate 1900fps and 74gn Varget a good recoil practicing 2365 fps again with very good accuracy.
I ran an 87gr load of H4350 for 2415fps but had to het treat the alloy to get there.
That may give you some place to work from for your 416.

I have loaded various weight in my 416 Rigby. Not at home at the moment so can not give specific loads but have used Trail Boss and AR2206H.

I'll try and remember to come back to this thread when I do get home and add the data.

Home, here are some of my results.

AR2206H is also Hodgdon H4895

445grain CBE410FN CAST 68grains AR2206H = 1940FPS

415gr NEI 380-6C CASTV 65GR AR2206H = 2012FPS

370GR RCBS 350-FN 65 GR AR2206H = 2030FPS

I can use more powder as the projectiles I am using are hard cast with gas checks. I was just after plinking loads.

Trail Boss. I use 32 to 36 grains and all bullet weights produce between 1450 and 1700 fps.

Thanks for the replies and information I am only push my loads to 18-1900fps.