You can buy parts on ebay, there are people parting out 73’s all the time on there but first you need to find out what you have since 30 cal was not a 73 cartridge. They were made in 44, 38, 32 and 22 caliber. If you send me some pictures of your gun I can tell you what caliber it is. One picture of the right side of the receiver and another of the barrel and mag tube. Send them to my email address at the bottom of this post.

Bob