When a weight's put on a rifle barrel at the muzzle, the barrel whips at a different frequency and harmonics for each shot. That extra weight makes the frequency lower. If it changes such that the bullet's leave while the muzzle axis is on the down swing, accuracy will be compromised. Slower bullets will leave at a lower angle, faster ones at a higher angle.
Best accuracy happens when the opposite happens. Slower bullets leaving at a higher/greater angle are compensated for their drop. Faster ones won't drop as much down range so their leaving at a lower angle doesn't cause a problem. This is the reason why the Brit's .303 SMLE's were so accurate at ranges past 500 yards with ammo having big muzzle velocity spreads.
So, I think your accuracy will change; maybe better, maybe worse.
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master