Need help in finding bullets for loading ammo. I am looking for 400 gr. cast. I have several rounds for this rifle which is chambered for 50/45. The ammo that I have was made from cut down 50/70 bell cases. I have never loaded black powder but do load smokeless. Does anyone have any info on a load for this rifle. The rifle is a remington rolling block saddle ring carbine in 50/70 caliber. I just never got into black powder reloading.