6,5x54mm M-S Loads

[fsrmg1]

I noticed that a lot of the pre-war Steyr 6,5x54 M-S rifles have an oversized groove diameter of up to .268". How do they shoot with a conventional .264" bullet? Does this cause a lot of gas cutting and copper fouling? It looks like only Hornady and PPU make proper sized bullets, but that is still such a limiting factor to only have a couple options.

 

[Mannlicher]

I am owning 2 M 1903 in 6,5x54MS - one with 45cm barrel (Stutzen) and one with 60 cm (take down).
Best results with 160 gr Hornady RN and 156 gr Lapua Mega. Both .264 diam. Also the Standard factory load
of RWS - 10,3 g RN - has .264 diam. . Light bullets are not recommented for the 6,5 MS. Round nose bullets are
my favorites, , no spitzer.

Mannlicher