Mystery solved regarding my 'double shoulder'.

I understand that the 'double shoulder' was common when the Dutch East Indies rifle/carbines were re-bored/re-chambered to 303 Brit since the 303 has a sharper taper. What puzzled me was that my bore was still the original 6.5mm. It turns out that I have a Dutch Mannlicher that is chambered (badly) for 6.5/303. I just ran a 303 case through a 6.5 mm neck sizing die down to a point where the rim to neck length was the same as the fired case and it chambered perfectly. I then made up a dummy round with a Woodleigh 160 gr round nose and seated it to the base of the neck and it chambered without any difficulty.

If nothing else it makes forming brass a heap easier! That said I will trim the formed case by .020 inches because it is exceptionally close to the chamber length indicated by the chamber cast.

Murray