Andy Calpin once won a national UKAHFT round outright using an FT rifle and scope (Ripley AR5S & Tasco Custom Shop) - and he did it all kneeling and standing, apart from the 3 prone only lanes where he had to shoot prone under protest.
That's with a 60mm objective lens, he just turned it down to 10x mag and shot it blurred.
I also shot round with a lad (can't remember his name) who cleared a UKAHFT national round (North Oxon) with a Simmons scope on 20x mag. So it's possible to do if you can point the gun in the right direction.
Give it a go and see how you get on, it's not the Olympics, no one will care what score you get apart from you, and if you don't do so well, you've got a pre-made excuse