Wow, you sure went through a lot of effort.
I have owned several bone stock 96 Mausers and one 38. The 38 & 1 96 had handgun scopes mounted on S&K mounts that replaced the rear sight. Either would do 1.5 MOA with several handloads. The other 96 had a G&H sidemount with a Lyman Alaskan with a 6X Litscherts upgrade. With 140 gr Sierra MKHPs and W 760, it would put 10 in one hole all day long. None of these rifles were "tuned" at all.
The most accurate 6.5x55 I have ever seen (and own) is a Tikka 595 Master Sporter, a genuine 1/2 MOA rifles (in all calibers).
Good Luck with your project !
