Rpeck, please PM me an email address where I can send you M66 related .Pdf documents as I don't know how to post them on the Forum. With regards to adding a 9,3x62 barrel to your 270 existing one, this should be possible as both calibers belong to the same group of exchangeable barrels for Mauser 66. With regards to ordering a new barrel, please see websites in Germany in my post on top of this thread. On the subject of scope mounts, my two M66 (7x64 & 8x68S) are fitted with claw mounts - which is quite the norm in Europe for quality rifles, but I saw on your photos that your M66 is already drilled so you may decide on other types of scope mounts. Louis