I understand the weatherby action is 34.2mm while the SAV is 34.4mm, The barrel nut takes the place of the shoulder, could probably expend a few neurons arguing whether or not it contributes to the strength, I’d say so though.

With the lug not adding to strength; has anyone interference fit it for this purpose??

Bolt thrust; I’m chambering an improved case with minimal slope and bolt thrust is directly proportional to this geometry. Parker famously tested his chambering WITHOUT a bolt and the case stayed put while the un-improved ‘slopey’ cases shot out at almost projectile velocity. Even without the improved cases; as long as you make sure there is NO OIL in the chamber area; bolt thrust should not be an issue. Make sure you wipe out the chamber before use!!

Area of lugs; I tried to work it out some time ago; I came to the conclusion that there was not an appreciable increase in shear area on the wby multi-lug .

Appreciate the input mate.