Lionelbudge,
Please have a peek here :
http://www.6mmbr.com/fieldtargetposition.html
FT Rules etc. :
https://www.thebfta.net/
HFT rules etc. :
http://www.swefta.org.uk/swefta-hunt...-target-rules/
HFT, as its name might suggest, has rules that are more specific in places - e.g. max. mag limit on scope (IIRC, 12x), and you are not allowed to alter parallax on when your eye is at the scope - so no parallax ranging.
Have fun & a good weekend
Best regards
Russ