They also forbid any cocking aids (or gloves or fingerstalls) and the bow has to be drawn by hand... that will probably limit the poundage that most people can draw...
Nice to see another society going against the specific safety instructions of crossbow manufacturers. I see litigation on the horizon - limited to what can be drawn by hand when the manufacturers specifically state not to be drawn by hand. Hmmm.
I have only seen a crossbow at one GNAS shoot ever... and that was the National Flights.
As the rules also state that they shall shoot on a separate target from other bowstyles, they are effectively banned because competitions aren't going to waste a boss for maybe a single archer, when they can get the entry fee for four. Field shoots tend to stipulate that crossbows are banned from their shoots.
Not to mention the fact that the RoS mostly cover what's allowed in competition. Outside of competition is a different matter.
Worrying about an almost non-existent bowstyle in GNAS' world isn't worth the effort. If someone was thinking of being serious about target crossbow in the UK they'd not be going to GNAS shoots, but those organised by the
National Crossbow Federation, who follow the rules set out by the WCSA (World Crossbow Shooting Association), which includes for target crossbow...
The draw weight is 95lbs (43 kg) max. Draw length 12". The total weight of the crossbow can be up to 22lbs (10 kg). Butt hooks are allowed as are open or aperture sights (no magnifying sights). No loading devices are allowed, the crossbow must be drawn by hand.
If you've chosen to shoot a crossbow that can't be shot (well, drawn) safely under the rules of the organisation that you want to shoot at, that's on you. If you buy a 70lb compound, you can't grump about not being able to go to GNAS shoots with it.