Using Pre-ban uppers for post ban builds

[BattleRifleG3]

Ok, say there's a muzzle brake out there that strikes my fancy, and it's available for pre-ban barrels. Would it be legal to buy a current manufacture pre-ban style upper and permanently attach the brake, then grind down the bayonet lug before installing it?

[kck]

Yes It is legal.You made the upper post ban legal with the permanant brake,and losing the bayonet lug.

[BattleRifleG3]

I thought so, but with so many "you can't use it if it came from here" laws, ya gotta ask. Thanks for the info!