Hi,
I personally have not done it, and would not use 6.5mm bullets in a .25 Cal rifle. If the bore was weak, I would slug the barrel to determine exact dimensions.
The very largest you would want to exceed with jacketed bullets would be .002". Changing bullet diameter would have an impact on pressure, and could be dangerous.
I have some 303 Savage CIL bullets that measure .310", .002" oversize. However, I am hesitant to load these bullets as I do not have any loading data.
In addition, the design on the .264" bullet may not work well in the twist rate of the 25/35, compromising accuracy.
Chris
