Re: 6.5 wssm
If I were making the call, I would opt for a 6.5 WSM over a 6.5 WSSM. The 7mm (or 277) WSM will have a larger case capacity. Additionally, the WSSM brass has been criticized for inconsistent accuracy related to thick necks. Just about every rifle maker that ever produced a WSSM rifle has discontinued their line making future availability of brass a distant second to the WSM brass. Just my two cents.