I don't think there is an official #5 weight record. In the UK we have the BFCC which is the only national club and these are our records Records | BFCC - Home Of Uk Fly Casting
I know Rick has thrown 140ish in practice, I have watched Paul Arden cast many over 130 including the outright BFCC record. I have cast several over 130 (best 138) in practice. Records have to be cast in competition, and there's the problem. You don't get to choose when when you get your three minutes like you do when you practice. The chances of those three minutes co-insiding with perfect conditions are slim to say the least.