Well unless your barrel is threaded it won't screw on. And yes it does seem to alter POI. Funnily enough we were at the tunnel (100 yard) range last night and John has a T3 Tactical and a Sako Finnlite, the Sako is threaded as he uses a Sound Moderator (Silencer) common here in the UK for Deer Stalking and he tried the Sako with the Muzzle brake and the POI was way off. Shooting with the Sound Mod then with bare barrel alters the POI about 5" vertically with 150 grain Sako factory .308 ammo using the brake it's even more

We have not noticed a real difference using the brake in accuracy but the Sound Mod certainly makes difference for the better groups with this Sako factory ammo anyway.