As techguy says SGC countersignatory has to be a person of 'standing', FAC referees can be anyone that has know you for the allotted time (aside from those specified on the form). On my grant i just used 2 of my mates that i've known since school - no probs
Thanks for the replies guys and gals. I'll call the firearms department (its Hampshire so I won't hold my breath on getting through) but failing that, I've got a friend who is a nurse. That should cover it hopefully.
Has known you personally for at least 2 years
Thinks you are an honest upright trustworthy citizen
Doesn't have hangups about guns
Shows up when you go looking for them in cyberspace or on some official record (The Army List, the register of solicitors / barristers / MPs / used-care salesmen / whatever)
Comes up as a complete blank on criminal records.
As long as the person you ask has enough standing in society that the police can actually refer to them if necessary and isn't themselves a crook, you should be fine.