Can cleaning a muzzle brake on a precision rifle change group any after a cleaning?

My rifle shot .250” groups all day long until I removed Fat Bastasd muzzle brake and cleaned it. It was carbon filing really bad. Now brake is cleaned my group’s are about an inch now compared to the .250” prior to cleaning.

I have two go to loads for rifle and now both have changed. This is the only thing I’ve done to rifle so is this possible?  Point of impact is same just grouping bigger.

I didn’t mention the rifle due to this problem should apply to any platform I would think.
Thanks ahead.

Change in torque working some magic on the rifling?

Did you mess up the threads or forget a shim? In theory shim distance would function like a non-adjustable tuner.

Ding the crown when cleaning?

Did you pull the action out of the stock? Action screw torque?

ETA: are these a new batch of loads or ones you previously shot? Just because you used the same recipe doesn't mean it came out right. Or maybe a different lot # of factory ammo (but I doubt factory is shooting ¼")

The brake is self timing.

The loads are the same recipe that I’ve shot for a while now with same good results. I anneal regularly and use a foster shoulder neck die for die use. I do the best I can to follow exact process. Still using powder from an eight pound jug for a while now.  

I have not had the action out of stock in a while. I will check torque on all fasteners in morning though.

When I put brake back on I just tightened it down.  Maybe I should remove and the torque it to spec.

Play with the torque on the brake..

Just curious what you used to clean the brake and how. I tried cleaning my aluminum brake after putting about 8000 rounds through it. That carbon did not want to come off. I tried soaking it jn various solvents and cleaning products but I eventually resorted to picking it out with a sharp screwdriver.