Why would you ever want to replace a prometheus tightbore?? lol
Dont worry, you dont need to have the EXACT elngth of barrel required, and you dont need to fill up every last mm of available barrel space. And I know this is hard to believe, but you can actually use a silencer AS A SILENCER instead of hiding a barrel extension!!!
I KNOW! Isn't that just an amazing concept?? lol
Get a 455mm barrel instead of a 488, with a good gundoc, you won't notice a difference going from a 368 to 455mm barrel, let alone 488 to 455