RCBS makes a mold that normally drops them about 375gns and .448 diameter when cast from 20:1 alloy. Bertram and BELL both make cases, but the Bertram tends to be cheaper and quality is fine. As far as not casting yourself, here's a place that does loaded ammo, but I have not used any yet.
Aardvark Labs LLC
Glenn Anderson pres
PO Box 3180, Glen Ellyn IL 60137
They have a 43 Mauser load with a 346gn lead bullet. I have not checked it, but it ATB a binary tin:lead alloy, which is what you want for the older rifles. S/F...Ken M