Static shooting is open to anybody the same way UK clubs have open days.
Mullen7 is 100% correct, we normally open the Dynamic Shooting class/training to existing shooters for 2 main raisons :
- NTTC is a declared association with the French authorities and we want to make sure participants have no criminal records, ie : If the UK police is happy for someone to handle a firearm, it is good enough for me

- There is a lot to learn/assimilate over a WE so a participant nervous about handling firearms would slow down the teaching for the class.
Having said that, I experienced 3 occasions of full Dynamic Pistol classes made up of people with zero firearms background. One was "pink-shooting" where the female partners come to try their hubbies' hobby, one was made-up of doctors, prospective tribunal experts, studying "trauma by firearms" (I confirm nobody was shot & no autopsy was subsequently performed

All experiences were very conclusive. The final say lies with our head Instructor but I am pretty confident your brother would be very welcome & would like the class very much
