Ok, so we all know just how loud and annoying that little bugger is, and I myself want to do something about it, without going to expensive procedures, and extended downtime.  I figure that one reason the blast from the break is so much, is due to the fact that the clearance of the bullet to the end of the muzzle break is very close, right?  Would reaming out the bore of the muzzle break a few thous help any?  My only concern is that this could have a deteriorative effect on the bullet's trajectory when passing through the muzzle break.  What do you think?

Now if I am crazy, someone please tell me.  Also, if this is not a good option, I would like to know exactly how that break is attached to the bushy's (14.5" barrel so they say it's fixed) so I can see to having it replaced with a better option.
Thanks

If I remember correctly someone posted a message that he had enlarged the hole on his mini-Y and it decreased the noise significantly...

Before you open up the exit hole, there are a few things you should be aware of.  First, is how to enlarge the exit hole.  You have to be careful not to damage the crown of the barrel.  I guess you could take the upper off and open the hole up with a milling machine.  But, if you screw up, it will be expensive.  You could take the brake off, but Bushmaster blind pinned it, right?

Second, opening up the hole would reduce the noise, but also the effectiveness of the brake.  The brake is NOT loud for the shooter, only for the bystanders.  When I shoot, the sight picture doesn't change, allowing me to follow up with a second shot.  I've been trying to get the second shot off (and still hit the target) before the first round hits.  At 200 yds, I almost have enough time.

Its a great brake, why mess with it?

IMHO, this brake is too noisy for both shooter and bystanders. I didn't notice it until I was introduced to A2 FS and I have to say that mini-Y comp literally kills your ears.

To do it properly it would have to be reamed either on a mill, boring machine, or take the barrel off the upper and turn it in a lathe.  Doing it is not the problem.  What I really want to know is will it negatively affect accuracy?  If anyone can tell me, please do.

I tried.  The thing was still a concussion machine.

If you have the cash go ahead and have Kurt's Kustom Firearms put a brake on there for you.  You won't regret it.