A 22-250, 243, 260, 7mm-08 and a 358 for example, are all going to weigh different amounts. The web site weights would always be an approximation. The guy has been promptly responding and encouraging you to call him to try and work out a resolution. He offered 2 resolutions already.
They do need to update the website but when I see the same weight for all cartridges listed, I know they are an approximation. Based on the emails you are posting, I'd have no trouble working with MRC.
