My shooting buddy sent in the payment with his serial number and got one for his revolver - it was a literal 'drop-in' fit. I have not sent in for the $30.22 WMR cylinder for my wife's Heritage Rough Rider, but I think I should. If a barrel length is changed, then a new serial number and new registration must follow. BATF maintains this information and it cannot be altered. Can I change my Rough Rider barrel to a different size barrel? No, because your Rough Rider was registered to you with a certain barrel length and serial number. Example 1: RR22B4 RR stands for Rough Rider 22 explains it is small bore B is the color 4 is the barrel length Example 2: RR22999MB6 RR = Rough Rider 22 = Bore Size 999= 9 Shot. An easy guide to understanding your rough rider, all your guns info is in your model number. Heritage Rough Rider Model number explanation. And are a guide to the price you may expect to be charged locally for those. Your e-mail address, street address, telephone number and purchase information will be kept strictly confidential. We will periodically send an e-mail to our customers advising them of new products. This information is for our records only.