I found this elsewhere from "One on top of two" moniker.
6.5 Creedmoor Users Please Note the Following:
URGENT AND IMPORTANT NEWSFLASH.
For those of you who use MOD Fixed Firing Ranges, particularly Wiltshire’s SPTA (Salisbury Plain Training Area) ranges (and most likely nationwide Military Fixed Firing Ranges).
With immediate effect, a ban on the use of 6.5 Creedmoor ammunition has been imposed. This ban has come from the top, Westdown Camp, who are responsible for safety on all MOD ranges across the UK, not just Wiltshire.
The issue appears to be with range safety and the use of 6.5 Creedmoor. ie this chambering exceeds the safety template of 7.62mm/308 Win by enough of a margin to be deemed unsafe for use on Fixed Firing Ranges.
When this ban came out (Thursday 26th) FCSA immediately informed NRA’s Nic Cauldry to seek clarification with MOD.
It is confirmed that the ban has been imposed. Furthermore, clubs and range users will need to acknowledge the ban (when other Training Areas bring it online) in writing, otherwise further range bookings will not be processed until said users have replied and acknowledged the restrictions on 6.5 Creedmoor.
If you need further information on this, contact your club’s secretary’s and seek clarification from your local MOD/Landmarc Representative.
Currently this ban is for SPTA users only, but we hear that it is likely to be rolled across all MOD Training areas where Fixed Firing Ranges are used by civilian clubs
And this from NRA website ..
The NRA is aware that Defence Infrastructure Organisation (DIO) has announced a new restriction on the use of the 6.5 Creedmoor cartridge on fixed ranges on the Salisbury Plain Training Area (SPTA). This restriction applies to NRA Clubs licenced to use SPTA ranges.
The NRA is working with our colleagues in DIO to better understand the restriction and any broader implications for civilian users of MoD ranges elsewhere in the United Kingdom. As we get more information, this will be communicated to members and Clubs.
Nic Couldrey
Regional Ranges Manager