An interesting and clear email. However, I must state that I have a major problem with the mindset in the wording quoted above; which appears to run counter to sporting shooters sticking together: 'united we stand'.
The wording appears to reflect a, perhaps subconscious, attempt to cross-contaminate other calibres and shooters, rather than focus on comparison with the actual primary threat to public safety.
The FCSA response absolutely shouldn't say 'a bad guy armed with a 300wm or 308'. Such language draws other sporting shooters into this facile HO argument, putting further wind in the sails of this new HO myth that terrorists would see stolen privately owned firearms as a realistic/practical route to arming themselves; which is a nonsense that's been discussed on here before: The terrorists' primary route is the easiest one; vehicles, knives and improvised explosives; with smuggled Eastern and Middle Eastern assault weapons a, more difficult, but equally attractive (to them) route.
The FCSA should not allow or endorse comparison with 'bad guys' armed with other sporting calibres (what a silly and dreadful term; 'bad guys'); you should be making comparisons with the primary threat that's prompting the review: Islamist terrorists (note: Islamist, not Islamic)) armed with eastern block military weapons in calibres, 7.62x39, 7.62x54 or 12.7mm, either obtained in Europe and the former USSR or in middle east.