Scotland has a 7 day limit on the time between asking for the 1:1 and for the disposal for the slot. Thankfully Edinburgh Rifles do a great service as RFDs, enabling this to go smoothly. This is the same policy as
@ashray reported in Thames Valley above, so it seems to be UK wide. Thanks to M@tt for finding where in the regulations this limit comes from.
As evidence: below is a cut and paste from a Firearms Scotland email me for a 1:1 done earlier in the year (converted to italics) so quoted text is clear:
OFFICIAL
Good morning (my name),
Thank you for your email.
To allow us to treat this application as a one for one with no fee, the rifle needs to be disposed of first and application submitted within 7 days of the disposal.
Is this something you can arrange then resubmit this email and attachments including the disposal notification?
Kind regards
(The FEO's name)
Firearms Licensing Administrator
Firearms and Explosive Licensing
Governance, Audit and Assurance
Police Scotland