Pinned and welded to be sure. Some states still mandate the "Permanently secured muzzle device".
They are pretty easy to spot if you know what to look for. Before you go tearing out the wrench next time take some time and examine the Muzzle device really well. Usually you will find a spot that is slightly discolored or has sanding/file marks. Take a file lightly to that spot. You will typically find that it is harder than the surrounding metal. That is why the finish looks different. Parkerizing will take differently on different hardness/alloys.
The way I deal with them is via the mill.
A 1/4 or 3/16th" carbide mill will chew through the hardest weld bead. Once you get through the weld the pin will usually start to spin in its hole. I have always been able to blow them out or pluck them with a magnet at this point.
Remove muzzle device as normal.
If you dont have a mill then careful use of a die grinder with a carbide burr or stone will suffice.
Forget a drill press and drilling it out. You will just burn up HSS bits (How did I know that?)
BTW- The only time you have to worry about permanently securing the muzzle device is:
1- You live in one of the states that still has a ban in effect.
2- The barrel is less than 16" without the device. At that point you need to install a device and permantly secure it so the total length is in excess of 16"
There are 4 methods of "Permanently securing a Muzzle Device" that is acceptable to the BATF:
1- Fusion weld no less than 180 degrees around the circumference of the device.
2- 4 equally spaced tack welds around the circumference of the device.
3- Silver Soldering with a melting point of 1100 degrees or more.
4- Blind pin and weld pin by fusion welding.